1
|
Woods S, McKiel A, Herda T, Klentrou P, Holmes MWR, Gabriel DA, Falk B. Different discrete motor-unit activation patterns in the flexor carpi radialis in boys and men. Eur J Appl Physiol 2024; 124:1933-1942. [PMID: 38285213 DOI: 10.1007/s00421-024-05417-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 01/06/2024] [Indexed: 01/30/2024]
Abstract
BACKGROUND Lower activation of higher threshold (type-II) motor units (MUs) has been suggested in children compared with adults. We examined child-adult differences in discrete MU activation of the flexor carpi radialis (FCR). METHODS Fifteen boys (10.2 ± 1.4 years), and 17 men (25.0 ± 2.7 years) completed 2 laboratory sessions. Following a habituation session, maximal voluntary isometric wrist flexion torque (MVIC) was determined before completing trapezoidal isometric contractions at 70%MVIC. Surface electromyography was captured by Delsys Trigno Galileo sensors and decomposed into individual MU action potential trains. Recruitment threshold (RT), and MU firing rates (MUFR) were calculated. RESULTS MVIC was significantly greater in men (10.19 ± 1.92 Nm) than in boys (4.33 ± 1.47 Nm) (p < 0.05), but not statistically different after accounting for differences in body size. Mean MUFR was not different between boys (17.41 ± 7.83 pps) and men (17.47 ± 7.64 pps). However, the MUFR-RT slope was significantly (p < 0.05) steeper (more negative) in boys, reflecting a progressively greater decrease in MUFR with increasing RT. Additionally, boys recruited more of their MUs early in the ramped contraction. CONCLUSION Compared with men, boys tended to recruit their MUs earlier and at a lower percentage of MVIC. This difference in MU recruitment may explain the greater decrease in MUFR with increasing RT in boys compared with men. Overall, these findings suggest an age-related difference in the neural strategy used to develop moderate-high torque in wrist flexors, where boys recruit more of their MUs earlier in the force gradation process, possibly resulting in a narrower recruitment range.
Collapse
Affiliation(s)
- Stacey Woods
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Andrew McKiel
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Trent Herda
- School of Education and Human Sciences, University of Kansas, Lawrence, KS, USA
| | - Panagiota Klentrou
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Michael W R Holmes
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - David A Gabriel
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Bareket Falk
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
| |
Collapse
|
2
|
Hovorka M, Prinz B, Simon D, Zöger M, Rumpl C, Nimmerichter A. Long-Term Alterations in Pulmonary V˙O2 and Muscle Deoxygenation On-Kinetics During Heavy-Intensity Exercise in Competitive Youth Cyclists: A Cohort Study. Pediatr Exerc Sci 2024:1-7. [PMID: 38714302 DOI: 10.1123/pes.2023-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 02/20/2024] [Accepted: 03/12/2024] [Indexed: 05/09/2024]
Abstract
PURPOSE The aim of this investigation was to assess alterations of pulmonary oxygen uptake (V˙O2) and muscle deoxygenation on-kinetics during heavy-intensity cycling in youth cyclists over a period of 15 months. METHODS Eleven cyclists (initial age, 14.3 [1.6] y; peak V˙O2, 62.2 [4.5] mL·min-1·kg-1) visited the laboratory twice on 3 occasions within 15 months. Participants performed an incremental ramp exercise test and a constant workrate test within the heavy-intensity domain during the first visit and second visit, respectively. Subsequently, parameter estimates of the V˙O2 and muscle deoxygenation on-kinetics were determined with mono-exponential models. RESULTS The V˙O2 phase II time constant decreased from occasion 1 (34 [4] s) to occasion 2 (30 [4] s, P = .005) and 3 (28 [4] s, P = .010). However, no significant alteration was observed between occasions 2 and 3 (P = .565). The V˙O2 slow component amplitude either expressed in absolute values (ie, L·min-1) or relative to end exercise V˙O2 (ie, %) showed no significant changes throughout the study (P = .972 and .996). Furthermore, the muscle deoxygenation on-kinetic mean response time showed no significant changes throughout the study (18 [8], 18 [3], and 16 [5] s for occasions 1, 2, and 3, respectively; P = .279). CONCLUSION These results indicate proportional enhancements of local muscle oxygen distribution and utilization, which both contributed to the speeding of the V˙O2 on-kinetics herein.
Collapse
Affiliation(s)
- Matthias Hovorka
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
- Centre for Sport Science and University Sports, University of Vienna, Vienna,Austria
- Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, Vienna,Austria
| | - Bernhard Prinz
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Dieter Simon
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Manfred Zöger
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Clemens Rumpl
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Alfred Nimmerichter
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
- Centre for Sport Science and University Sports, University of Vienna, Vienna,Austria
| |
Collapse
|
3
|
McKiel A, Woods S, Gabriel DA, Vandenboom R, Falk B. Post-activation potentiation and potentiated motor unit firing patterns in boys and men. Eur J Appl Physiol 2024; 124:1561-1574. [PMID: 38159138 DOI: 10.1007/s00421-023-05377-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Post-activation potentiation (PAP) describes the enhancement of twitch torque following a conditioning contraction (CC) in skeletal muscle. In adults, PAP may be related to muscle fibre composition and is accompanied by a decrease in motor unit (MU) firing rates (MUFRs). Muscle fibre composition and/or activation is different between children and adults. This study examined PAP and MU firing patterns of the potentiated knee extensors in boys and men. METHODS Twenty-three boys (10.5 ± 1.3 years) and 20 men (23.1 ± 3.3 years) completed familiarization and experimental sessions. Maximal isometric evoked-twitch torque and MU firing patterns during submaximal contractions (20% and 70% maximal voluntary isometric contraction, MVIC) were recorded before and after a CC (5 s MVIC). PAP was calculated as the percent-increase in evoked-twitch torque after the CC. MU firing patterns were examined during submaximal contractions before and after the CC using Trigno Galileo surface electrodes (Delsys Inc) and decomposition algorithms (NeuroMap, Delsys Inc). MU action potential amplitudes (MUAPamp) and MUFRs were calculated for each MU and exponential MUFR-MUAPamp relationships were calculated for each participant and trial. RESULTS PAP was higher in men than in boys (98.3 ± 37.1% vs. 68.8 ± 18.3%, respectively; p = 0.002). Following potentiation, the rate of decay of the MUFR-MUAPamps relationship decreased in both contractions, with a greater decrease among boys during the high-intensity contractions. CONCLUSION Lower PAP in the boys did not coincide with smaller changes in potentiated MU firing patterns, as boys had greater reductions in MUFRs with potentiation compared with men in high-intensity contractions.
Collapse
Affiliation(s)
- Andrew McKiel
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Stacey Woods
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - David A Gabriel
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Rene Vandenboom
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Bareket Falk
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada.
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
| |
Collapse
|
4
|
McKiel A, Woods S, Faragher M, Taylor G, Vandenboom R, Falk B. Optimization of post-activation potentiation in girls and women. Eur J Appl Physiol 2024:10.1007/s00421-024-05475-6. [PMID: 38652270 DOI: 10.1007/s00421-024-05475-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/17/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Maximal conditioning contractions (CCs) can lead to the enhancement of evoked-twitch characteristics in human skeletal muscle. This phenomenon is termed post-activation potentiation (PAP). In the knee extensors, PAP is greater in men compared with boys. In adults, the optimal CC duration for PAP is ~ 10 s. We examined child-adult differences in PAP among females and aimed to determine the optimal CC duration in girls and women. METHODS Eleven girls (9.3 ± 1.4 years) and 13 women (23.4 ± 2.7 years) participated in this study. Maximal isometric evoked twitches were recorded in the knee extensors before and after 4 maximal CCs of different durations (5, 10, 20, and 30 s), in a random order. PAP was calculated as the percent-change in peak torque (Tpeak) and peak rate of torque development (RTDpeak) after each CC. RESULTS There was a group-by-duration interaction (p < 0.001), reflecting greater Tpeak PAP in women compared with girls following 5 and 10 s CCs, and lower RTDpeak PAP in women following the 30 s CC. The 5 and 10 s CCs lead to the greatest Tpeak and RTDpeak PAP amongst the women while there were no differences between CC durations in girls. CONCLUSION After both a 5 and 10 s CC, women have greater PAP compared with girls. The optimal CC duration for the knee extensors in women appears to be ~ 5-10 s, while CC durations between 5 and 30 s do not appear to affect levels of PAP in girls.
Collapse
Affiliation(s)
- Andrew McKiel
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Stacey Woods
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - McKenna Faragher
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Gregory Taylor
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Rene Vandenboom
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Bareket Falk
- Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada.
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
| |
Collapse
|
5
|
Andries A, Deschrevel J, Maes K, De Beukelaer N, Corvelyn M, Staut L, De Houwer H, Costamagna D, Nijs S, Metsemakers WJ, Nijs E, Hens G, De Wachter E, Prinsen S, Desloovere K, Van Campenhout A, Gayan-Ramirez G. Histological analysis of the medial gastrocnemius muscle in young healthy children. Front Physiol 2024; 15:1336283. [PMID: 38651045 PMCID: PMC11034367 DOI: 10.3389/fphys.2024.1336283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Introduction: Histological data on muscle fiber size and proportion in (very) young typically developing (TD) children is not well documented and data on capillarization and satellite cell content are also lacking. Aims: This study investigated the microscopic properties of the medial gastrocnemius muscle in growing TD children, grouped according to age and gender to provide normal reference values in healthy children. Methods: Microbiopsies of the medial gastrocnemius (MG) muscle were collected in 46 TD boys and girls aged 2-10 years subdivided into 4 age groups (2-4, 4-6, 6-8 and 8-10 years). Sections were immunostained to assess fiber type cross-sectional area (fCSA) and proportion, the number of satellite cells (SC), capillary to fiber ratio (C/F), capillary density for type I and II fiber (CFD), capillary domain, capillary-to-fiber perimeter exchange index (CFPE) and heterogeneity index. fCSA was normalized to fibula length2 and the coefficient of variation (CV) was calculated to reflect fCSA intrasubject variability. Results: Absolute fCSA of all fibers increased with age (r = 0.72, p < 0.001) but more in boys (+112%, p < 0.05) than in girls (+48%, p > 0.05) Normalized fCSA, CV and fiber proportion did not differ between age groups and gender. C/F was strongly correlated with age in boys (r = 0.83, p < 0.001), and to a lesser extent in girls (r = 0.37, p = 0.115), while other capillary parameters as well as the number of SC remained stable with increasing age in boys and girls. Discussion: This study provides reference values of histological measures in MG according to age in normally growing boys and girls. These data may be used as a reference to determine disease impact and efficacy of therapeutic approach on the muscle.
Collapse
Affiliation(s)
- Anke Andries
- Laboratory of Respiratory Diseases and Thoracic Surgery, Department of Chronic Diseases and Metabolism, KU-Leuven, Leuven, Belgium
| | - Jorieke Deschrevel
- Laboratory of Respiratory Diseases and Thoracic Surgery, Department of Chronic Diseases and Metabolism, KU-Leuven, Leuven, Belgium
| | - Karen Maes
- Laboratory of Respiratory Diseases and Thoracic Surgery, Department of Chronic Diseases and Metabolism, KU-Leuven, Leuven, Belgium
| | - Nathalie De Beukelaer
- Neurorehabilitation Group, Department of Rehabilitation Sciences, KU-Leuven, Leuven, Belgium
| | - Marlies Corvelyn
- Stem Cell and Developmental Biology, Department of Development and Regeneration, KU-Leuven, Leuven, Belgium
| | - Lauraine Staut
- Neurorehabilitation Group, Department of Rehabilitation Sciences, KU-Leuven, Leuven, Belgium
| | - Hannah De Houwer
- Pediatric Orthopedics, Department of Development and Regeneration, KU-Leuven, Leuven, Belgium
| | - Domiziana Costamagna
- Neurorehabilitation Group, Department of Rehabilitation Sciences, KU-Leuven, Leuven, Belgium
- Stem Cell and Developmental Biology, Department of Development and Regeneration, KU-Leuven, Leuven, Belgium
- Exercise Physiology Research Group, Department of Movement Sciences, KU-Leuven, Leuven, Belgium
| | - Stefaan Nijs
- Department of Trauma Surgery, University Hospitals Leuven, Leuven, Belgium
| | | | - Elga Nijs
- Department of Trauma Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Greet Hens
- Department of Ear Nose Throat, University Hospitals Leuven, Leuven, Belgium
| | - Eva De Wachter
- Department of Orthopaedic Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Sandra Prinsen
- Department of Orthopaedic Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Kaat Desloovere
- Neurorehabilitation Group, Department of Rehabilitation Sciences, KU-Leuven, Leuven, Belgium
| | - Anja Van Campenhout
- Pediatric Orthopedics, Department of Development and Regeneration, KU-Leuven, Leuven, Belgium
| | - Ghislaine Gayan-Ramirez
- Laboratory of Respiratory Diseases and Thoracic Surgery, Department of Chronic Diseases and Metabolism, KU-Leuven, Leuven, Belgium
| |
Collapse
|
6
|
Woods S, McKiel A, Herda T, Klentrou P, Holmes M, Gabriel D, Falk B. Developmental changes in motor unit activity patterns: child-adult comparison using discrete motor unit analysis. Appl Physiol Nutr Metab 2024. [PMID: 38471135 DOI: 10.1139/apnm-2023-0339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Using global surface electromyography (sEMG) and the sEMG threshold it has been suggested that children activate their type-II motor unit (MU) to a lesser extent compared with adults. However, when age-related differences in discrete MU activation are examined using sEMG decomposition this phenomenon is not observed. Furthermore, findings from these studies are inconsistent and conflicting. Therefore, the purpose of this study was to examine differences in discrete MU activation of the vastus lateralis (VL) between boys and men during moderate-intensity knee extensions. Seventeen boys and 20 men completed two laboratory sessions. Following a habituation session, maximal voluntary isometric knee extension (MVIC) torque was determined before completing trapezoidal contractions at 70% MVIC. sEMG of the VL was captured and mathematically decomposed into individual MU action potential trains. Motor unit action potential amplitude (MUAPamp), recruitment threshold (RT), and MU firing rates (MUFR) were calculated. We observed that MUAPamp-RT slope was steeper in men compared with boys (p < 0.05) even after accounting for fat thickness and quadriceps muscle depth. The mean MUFR and y-intercept of the MUFR-RT relationship were significantly (p < 0.001) lower in boys than in men. The slope of the MUFR-RT relationship tended to be steeper in men, but the differences did not reach statistical significance (p = 0.056). Overall, our results suggest that neural strategies used to produce torque are different among boys and men. Such differences may be related, in part, to boys' lower MUFR and lesser ability to activate their higher-threshold MUs. Although, other factors (e.g., muscle composition) likely also play a role.
Collapse
Affiliation(s)
- Stacey Woods
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Andrew McKiel
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Trent Herda
- School of Education and Human Sciences, University of Kansas, Lawrence, KS, USA
| | - Panagiota Klentrou
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Michael Holmes
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - David Gabriel
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Bareket Falk
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| |
Collapse
|
7
|
Sudlow A, Galantine P, Del Sordo G, Raymond JJ, Dalleau G, Peyrot N, Duché P. Influence of Growth, Maturation, and Sex on Maximal Power, Force, and Velocity During Overground Sprinting. J Strength Cond Res 2024; 38:491-500. [PMID: 38416445 DOI: 10.1519/jsc.0000000000004645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
ABSTRACT Sudlow, A, Galantine, P, Del Sordo, G, Raymond, J-J, Dalleau, G, Peyrot, N, and Duché, P. Influence of growth, maturation, and sex on maximal power, force, and velocity during overground sprinting. J Strength Cond Res 38(3): 491-500, 2024-In pediatric populations maximal anaerobic power, force, and velocity capabilities are influenced by changes in body dimensions and muscle function. The aim of this study was to investigate the influences of growth, maturation, and sex on short-term anaerobic performance. One hundred forty children pre-, mid-, and postpeak height velocity performed two 30-m sprints concurrently measured using a radar device. Maximal power (Pmax), force (F0), and velocity (v0) were calculated from sprint velocity-time data and normalized using sex-specific, multiplicative, allometric models containing body mass, fat-free mass (FFM), or height, and chronological age. Absolute values for Pmax, F0, and v0 were higher with increasing maturity (p < 0.01; d ≥ 0.96), and boys had greater outputs than girls (p < 0.01; d ≥ 1.19). When Pmax and v0 were scaled all maturity-related and sex-related differences were removed. When F0 was scaled using models excluding age, all maturity-related differences were removed except for the least mature group (p < 0.05; d ≥ 0.88) and boys maintained higher values than girls (p < 0.05; d ≥ 0.92). All maturity-related and sex-related differences were removed when F0 was scaled using models including age. Maturity-related and sex-related variance in Pmax and v0 can be entirely explained when FFM, height, and chronological age are accounted for. Regarding F0, there seems to be a threshold after which the inclusion of age is no longer necessary to account for maturity-related differences. In young prepubertal children, the inclusion of age likely accounts for deficits in neuromuscular capacities and motor skills, which body dimensions cannot account for. Practitioners should focus on eliciting neural adaptations and enhancing motor coordination in prepubertal children to improve anaerobic performance during overground sprinting.
Collapse
Affiliation(s)
- Anthony Sudlow
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Paul Galantine
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Giovanna Del Sordo
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| | - Jean-Jacques Raymond
- Sports Medicine and Traumatology Unit, Hôpital Sainte Musse, CHITS, Toulon, France
| | - Georges Dalleau
- Laboratory IRISSE, EA4075, University of La Réunion, Le Tampon, La Réunion
| | - Nicolas Peyrot
- Laboratory of Movement-Interactions-Performance, MIP, EA4334, University of Le Mans, Le Mans, France
| | - Pascale Duché
- Research Unit of impact of physical activitity on health, IAPS UR201723207F, University of Toulon, Toulon, France
| |
Collapse
|
8
|
Dotan R, Woods S, Langille J, Falk B. Boys-men mean-power-frequency differences in progressive exercise to exhaustion, confounded by variability and adiposity. Eur J Appl Physiol 2024; 124:491-505. [PMID: 37553549 DOI: 10.1007/s00421-023-05292-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/26/2023] [Indexed: 08/10/2023]
Abstract
BACKGROUND Only scant research has compared children's mean power frequency (MPF) to adults', with a clear overview still lacking. A significant obstacle has been MPF's high variability, which this study aimed to overcome by elucidating the MPF characteristics distinguishing boys from men in progressive exhaustive exercise. METHODS Electromyographic (EMG) data of 20 men (23.5 ± 2.5yrs) and 17 boys (10.2 ± 1.0 yrs), who performed progressively exhausting, intermittent isometric knee extensions, were subjected to secondary MPF analysis. Participants' vastus lateralis MPF data series were transformed to third-order polynomial regressions and expressed as percentages of the peak polynomial MPF values (%MPFpeak). The resulting curves were compared at 5-% time-to-exhaustion (TTE) intervals, using repeated-measures ANOVA. Raw MPFpeak values were adiposity corrected to 0% fat and used to convert the %MPFpeak data back to absolute MPF values (Hz) for estimating muscle-level MPF. RESULTS No overall interaction or group effects could be shown between the %MPFpeak plots, but pairwise comparisons revealed significantly higher men's values at 50-70%TTE and lower at 100%TTE, i.e. boys' shallower MPF rise and decline. The adiposity-corrected boys' and men's composite MPF values peaked at 125.7 ± 2.5 and 166.0 ± 2.4 Hz, respectively (110.7 ± 1.7 and 122.5 ± 2.1 Hz, uncorrected), with a significant group effect (p < 0.05) and pairwise differences at all %TTE points. CONCLUSIONS The boys were lower than the men in both the observed and, more so, in the adiposity-corrected MPF values that presumably estimate muscle-level MPF. The boys' shallower MPF rise and decline conform to children's claimed type-II motor-unit activation and/or compositional deficits and their related known advantage in muscular endurance.
Collapse
Affiliation(s)
- Raffy Dotan
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada.
| | - Stacey Woods
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada
| | - Jordan Langille
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada
| | - Bareket Falk
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada
| |
Collapse
|
9
|
Ferrari A, Baquet G, Blazevich AJ, Ratel S. Influence of Recovery Time After Warm-up on Vertical Jump Performance in Trained Prepubertal and Postpubertal Male Athletes. J Strength Cond Res 2023; 37:1985-1992. [PMID: 36930232 DOI: 10.1519/jsc.0000000000004487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
ABSTRACT Ferrari, A, Baquet, G, Blazevich, AJ, and Ratel, S. Influence of recovery time after warm-up on vertical jump performance in trained prepubertal and postpubertal male athletes. J Strength Cond Res 37(10): 1985-1992, 2023-The aim of this study was to examine the concurrent effects of maturity status and recovery delay after a standardized dynamic warm-up on vertical jump performance. Thirteen prepubertal boys (9.4 ± 1.1 years) and 12 postpubertal boys (16.6 ± 0.8 years) were tested on squat jump (SJ) and drop jump from 30 cm (DJ 30 ) before and after a standardized, 8-minute, dynamic warm-up, including low-intensity, nonspecific dynamic exercises progressing to maximal, specific exercises, over 6 separate occasions. In each session, subjects jumped at 0, 1.5, 3, 5, 7, or 10 minutes after warm-up in a randomized order. Measurements included SJ height, DJ 30 height, ground contact time (GCT), and reactive strength index (RSI) from DJ 30 . The results revealed no significant recovery time × maturity group interaction effects for SJ height ( p = 0.36), DJ 30 height ( p = 0.45), GCT ( p = 0.75), or RSI ( p = 0.09), meaning that maturity status did not have a significant effect on changes in vertical jump performance after the warm-up. However, there were significant time effects for SJ height, DJ 30 height, and RSI ( p < 0.001 for all), with DJ 30 height and RSI increasing significantly by 16.9% at 1.5 minutes ( p < 0.001) and SJ height increasing significantly by 12.0% until 3 minutes after the warm-up ( p < 0.001). To conclude, the standardized dynamic warm-up had beneficial effects on vertical jump performance within the first 3 minutes after completion of the intervention. However, vertical jump performance after the warm-up was not dependent on the children's maturity status.
Collapse
Affiliation(s)
- Antoine Ferrari
- Lille University, Artois University, Littoral Côte d'Opale University, ULR 7369-URePSSS-Multidisciplinary Sport Health Society Research Unit, Lille, France
| | - Georges Baquet
- Lille University, Artois University, Littoral Côte d'Opale University, ULR 7369-URePSSS-Multidisciplinary Sport Health Society Research Unit, Lille, France
| | - Anthony J Blazevich
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
| | - Sébastien Ratel
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| |
Collapse
|
10
|
Hager A, Mazurak V, Noga M, Gilmour SM, Mager DR. Skeletal muscle fibre morphology in childhood-insights into myopenia in pediatric liver disease. Appl Physiol Nutr Metab 2023; 48:730-750. [PMID: 37319441 DOI: 10.1139/apnm-2023-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
TAKE-HOME MESSAGE Skeletal muscle morphology in healthy children changes with age. Liver disease may preferentially affect type II fibres in adults with end-stage liver disease (ESLD). More research is needed on the effects of ESLD on muscle morphology in children.
Collapse
Affiliation(s)
- Amber Hager
- Department of Agricultural, Food & Nutritional Sciences, University of Alberta, Edmonton, AB, Canada
| | - Vera Mazurak
- Department of Agricultural, Food & Nutritional Sciences, University of Alberta, Edmonton, AB, Canada
| | - Michelle Noga
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada
| | - Susan M Gilmour
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
- Division of Pediatric Gastroenterology & Nutrition/Transplant Services, The Stollery Children's Hospital, Alberta Health Services, Edmonton, AB, Canada
| | - Diana R Mager
- Department of Agricultural, Food & Nutritional Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
11
|
Sadowsky CL. Targeting Sarcopenia as an Objective Clinical Outcome in the Care of Children with Spinal Cord-Related Paralysis: A Clinician's View. CHILDREN (BASEL, SWITZERLAND) 2023; 10:837. [PMID: 37238385 PMCID: PMC10217275 DOI: 10.3390/children10050837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023]
Abstract
Muscle loss is consistently associated with immobility and paralysis and triggers significant metabolic and functional changes. The negative effects of sarcopenia are amplified in children who are in the process of building their muscle mass as part of development. Because muscle mass loss is consistently associated with increased morbidity and mortality throughout life, optimizing the size and health of muscles following a neurologic injury is an objective target for therapeutic interventions. This review hypothesizes that muscle mass correlates with functional outcomes in children with paralysis related to spinal cord-related neurologic deficits. We propose that the measurement of muscle mass in this population can be used as an objective outcome for clinical long-term care. Finally, some practical clinical approaches to improving muscle mass are presented.
Collapse
Affiliation(s)
- Cristina L. Sadowsky
- International Center for Spinal Cord Injury, Kennedy Krieger Institute, Baltimore, MD 21205, USA;
- Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
12
|
Skeletal Muscle Measurements in Pediatric Hematology and Oncology: Essential Components to a Comprehensive Assessment. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10010114. [PMID: 36670664 PMCID: PMC9856749 DOI: 10.3390/children10010114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/30/2022] [Accepted: 01/02/2023] [Indexed: 01/06/2023]
Abstract
Children with hematologic and oncologic health conditions are at risk of impaired skeletal muscle strength, size, and neuromuscular activation that may limit gross motor performance. A comprehensive assessment of neuromuscular function of these children is essential to identify the trajectory of changes in skeletal muscle and to prescribe therapeutic exercise and monitor its impact. Therefore, this review aims to (a) define fundamental properties of skeletal muscle; (b) highlight methods to quantify muscle strength, size, and neuromuscular activation; (c) describe mechanisms that contribute to muscle strength and gross motor performance in children; (d) recommend clinical assessment measures; and (e) illustrate comprehensive muscle assessment in children using examples of sickle cell disease and musculoskeletal sarcoma.
Collapse
|
13
|
Souron R, Carayol M, Martin V, Piponnier E, Duché P, Gruet M. Differences in time to task failure and fatigability between children and young adults: A systematic review and meta-analysis. Front Physiol 2022; 13:1026012. [DOI: 10.3389/fphys.2022.1026012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
The transition from childhood to adulthood is characterized by many physiological processes impacting exercise performance. Performance fatigability and time to task failure are commonly used to capture exercise performance. This review aimed to determine the differences in fatigability and TTF between youth (including both children and adolescents) and young adults, and to evaluate the influence of exercise modalities (i.e., exercise duration and type of exercise) on these differences. Medline, SPORTDiscus and Cochrane Library were searched. Thirty-four studies were included. The meta-analyses revealed that both children (SMD −1.15; p < 0.001) and adolescents (SMD −1.26; p = 0.022) were less fatigable than adults. Additional analysis revealed that children were less fatigable during dynamic exercises (SMD −1.58; p < 0.001) with no differences during isometric ones (SMD –0.46; p = 0.22). Children (SMD 0.89; p = 0.018) but not adolescents (SMD 0.75; p = 0.090) had longer TTF than adults. Additional analyses revealed 1) that children had longer TTF for isometric (SMD 1.25; p < 0.001) but not dynamic exercises (SMD −0.27; p = 0.83), and 2) that TTF differences between children and adults were larger for short- (SMD 1.46; p = 0.028) than long-duration exercises (SMD 0.20; p = 0.64). Children have higher endurance and are less fatigable than adults. These differences are influenced by the exercise modality, suggesting distinct physiological functioning during exercise between children and adults. The low number of studies comparing these outcomes between adolescents versus children and adults prevents robust conclusions and warrants further investigations in adolescent individuals.
Collapse
|
14
|
Possibility for Visualizing the Muscle Microstructure by q-Space Imaging Technique. Appl Bionics Biomech 2022; 2022:7929589. [PMID: 35979242 PMCID: PMC9377983 DOI: 10.1155/2022/7929589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/14/2022] [Accepted: 07/23/2022] [Indexed: 11/17/2022] Open
Abstract
In the human body, skeletal muscle microstructures have been evaluated only by biopsy. Noninvasive examination of the microstructure of muscles would be useful for research and clinical practice in sports and musculoskeletal areas. The study is aimed at determining if q-space imaging (QSI) can reveal the microstructure of muscles in humans. Forty-three Japanese subjects (controls, distance runners, powerlifting athletes, and teenage runners) were included in this cross-sectional study. Magnetic resonance imaging of the lower leg was performed. On each leg muscle, full width at half maximum (FWHM) which indicated the muscle cell diameters and pennation angle (PA) were measured and compared. FWHM showed significant positive correlations with PA, which is related to muscle strength. In addition, FWHM was higher for powerlifting, control, distance running, and teenager, in that order, suggesting that it may be directing the diameter of each muscle cell. Type 1 and type 2 fibers are enlarged by growth, so the fact that the FWHM of the control group was larger than that of the teenagers in this study may indicate that the muscle fibers were enlarged by growth. Also, FWHM has the possibility to increase with increased muscle fibers caused by training. We showed that QSI had the possibility to depict noninvasively the microstructure like muscle fiber type and subtle changes caused by growth and sports characteristics, which previously could only be assessed by biopsy.
Collapse
|
15
|
Mittal S, Garg B, Mehta N, Kumar V, Karpe A, Kakkar A, Sharma M, Sarkar C, Kotwal P. Histopathological, Ultrastructural, and Immunohistochemical Findings in Radial Longitudinal Deficiency: A Prospective, Observational Study. J Hand Surg Am 2022; 47:789.e1-789.e8. [PMID: 34452798 DOI: 10.1016/j.jhsa.2021.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 04/24/2021] [Accepted: 07/06/2021] [Indexed: 02/02/2023]
Abstract
PURPOSE To report the histopathological, electron microscopic, and immunohistochemical findings of tissue samples obtained from patients with radial longitudinal deficiency (RLD) and investigate the contribution of abnormality in soft tissues as a secondary driver of deformity in RLD. METHODS Specimens from radial-sided muscles and tendons were obtained at the time of surgery (either radialization or centralization) from 14 patients with 16 limbs affected with Bayne type 3 and type 4 RLD. The specimens were evaluated using light microscopy, electron microscopy, and immunohistochemical examination. RESULTS Among the 16 frozen muscle specimens, 6 (37%) showed normal muscle, while 10 (63%) showed the presence of atrophic fibers. The 6 cases with normal muscle showed no abnormality in fiber type distribution. Six patients showed predominance of type 1 muscle fibers. None of the specimens had myofibroblasts; 4 of 16 specimens had mast cells, and 9 of 16 specimens showed the presence of platelet derived growth factor-positive cells. Features of myofibroblasts (the presence of basal lamina, intercellular junctions, or pinocytic vesicles) were not identified in any specimen on electron microscopy. CONCLUSIONS The histopathological, electron microscopic, and immunohistochemical findings, in particular the absence of myofibroblasts, in tissue samples obtained from patients with RLD, do not support the assumption of abnormality in soft tissues as a secondary driver of deformity in RLD. CLINICAL RELEVANCE This study provides a preliminary insight into a possible role of soft tissues in the development of the deformity in RLD.
Collapse
Affiliation(s)
- Samarth Mittal
- Department of Orthopaedics, Jai Prakash Narayan Apex Trauma Centre, New Delhi, India
| | - Bhavuk Garg
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India.
| | - Nishank Mehta
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India
| | - Vijay Kumar
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India
| | | | - Aanchal Kakkar
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Mehar Sharma
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Chitra Sarkar
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Prakash Kotwal
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
16
|
Donti O, Konrad A, Panidi I, Dinas PC, Bogdanis GC. Is There a "Window of Opportunity" for Flexibility Development in Youth? A Systematic Review with Meta-analysis. SPORTS MEDICINE - OPEN 2022; 8:88. [PMID: 35792993 PMCID: PMC9259532 DOI: 10.1186/s40798-022-00476-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 06/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Flexibility is an important component of physical fitness for competitive and recreational athletes. It is generally suggested that flexibility training should start from childhood (6-11 years of age) to optimize joint range of motion (ROM) increases; however, evidence is limited and inconsistent. OBJECTIVE To examine whether there is a difference in the effect of stretching training on flexibility during childhood (6-11 years of age) and adolescence (12-18 years of age). DESIGN Systematic review and meta-analysis. METHODS We searched PubMed Central, Web of Science, Scopus, Embase, and SPORTDiscus, to conduct this systematic review. Randomized controlled trials and non-randomized controlled trials were eligible. No language and date of publication restrictions were applied. Risk of bias was assessed using Cochrane RoB2 and ROBINS-I tools. Meta-analyses were conducted via an inverse variance random-effects model. GRADE analysis was used to assess the methodological quality of the studies. RESULTS From the 2713 records retrieved 28 studies were included in the meta-analysis (n = 1936 participants). Risk of bias was low in 56.9% of all criteria. Confidence in cumulative evidence was moderate. We found that stretching was effective in increasing ROM in both children (SMD = 1.09; 95% CI = 0.77-1.41; Z = 6.65; p < 0.001; I2 = 79%) and adolescents (SMD = 0.90; 95% CI = 0.70-1.10; Z = 8.88; p < 0.001; I2 = 81%), with no differences between children and adolescents in ROM improvements (p = 0.32; I2 = 0%). However, when stretching volume load was considered, children exhibited greater increases in ROM with higher than lower stretching volumes (SMD = 1.21; 95% CI = 0.82-1.60; Z = 6.09; p < 0.001; I2 = 82% and SMD = 0.62; 95% CI = 0.29-0.95; Z = 3.65; p < 0.001; I2 = 0%, respectively; subgroup difference: p = 0.02; I2 = 80.5%), while adolescents responded equally to higher and lower stretching volume loads (SMD = 0.90; 95% CI = 0.47-1.33; Z = 4.08; p < 0.001; I2 = 83%, and SMD = 0.90; 95% CI = 0.69-1.12; Z = 8.18; p < 0.001; I2 = 79%, respectively; subgroup difference: p = 0.98; I2 = 0%). CONCLUSIONS Systematic stretching training increases ROM during both childhood and adolescence. However, larger ROM gains may be induced in childhood than in adolescence when higher stretching volume loads are applied, while adolescents respond equally to high and low stretching volume loads. REGISTRATION INPLASY, registration number: INPLASY202190032; https://inplasy.com/inplasy-2021-9-0032/.
Collapse
Affiliation(s)
- Olyvia Donti
- grid.5216.00000 0001 2155 0800School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Andreas Konrad
- grid.5110.50000000121539003Institute of Human Movement Science, Sport and Health, University of Graz, Graz, Austria
| | - Ioli Panidi
- grid.5216.00000 0001 2155 0800School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Petros C. Dinas
- grid.410558.d0000 0001 0035 6670FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Volos, Greece
| | - Gregory C. Bogdanis
- grid.5216.00000 0001 2155 0800School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
17
|
Bouzada J, Gemmell C, Konschake M, Tubbs RS, Pechriggl E, Sañudo J. New Insights Into the Development of the Anterior Abdominal Wall. Front Surg 2022; 9:863679. [PMID: 35433819 PMCID: PMC9008241 DOI: 10.3389/fsurg.2022.863679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/01/2022] [Indexed: 11/22/2022] Open
Abstract
Purpose Among the few studies that have examined the development of the anterior abdominal wall, several are based on incomplete “series”, substituted in many cases by non-human specimens. Material and Methods In total, 19 human embryos corresponding to Carnegie stages 15–23, 36 fetuses with estimated gestational ages ranging from 9 weeks to term, and eight neonates were included in this study. All specimens belong to the collection of the Department of Anatomy and Embryology at the Complutense University of Madrid. Results The muscles of the anterior abdominal wall appear in the dorsal region at stages 15 and 16 (33–37 days). At stages 17 and 18 (41–44 days), this muscular mass grows ventrally and splits into two sheets: the external abdominal oblique muscle and the common mass of the internal abdominal oblique, and the transversus abdominis muscles, all of which end ventrally in the primitive condensation of the rectus abdominis. In embryos at stages 19 and 20 (48 days), the anterior abdominal wall continues to show an umbilical hernia in the amniotic cavity. However, a narrow neck is apparent for the first time and there is a wider anterior abdominal wall below the hernia made up of dense mesenchyme tissue without layers and showing the primordia of the umbilical canal. In embryos at stages 21, 22, and 23 (51–57 days), the abdominal muscles and aponeuroses cross the midline (linea alba) covering the rectus abdominis and pyramidalis muscles while the umbilical hernia has shrunk. In fetuses during the 9th and 10th weeks, the umbilical hernia becomes encircled by the rectus abdominis muscle, its aponeurosis, and the three layers of lateral abdominal muscles, which are more developed and covered by Camper's and Scarpa's fasciae. The inguinal canal has a course and relationships like those described in adults, with Hesselbach's ligament.
Collapse
Affiliation(s)
- Jose Bouzada
- Department of Anatomy and Embryology, University Complutense of Madrid, Madrid, Spain
| | - Carolina Gemmell
- Department of Anatomy and Embryology, University Complutense of Madrid, Madrid, Spain
| | - Marko Konschake
- Department of Anatomy, Histology and Embryology, Institute of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
- *Correspondence: Marko Konschake ; orcid.org/0000-0002-9706-7396
| | - R. S. Tubbs
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Neurology, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Anatomical Sciences, St. George's University, St. George's, West Indies
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Neurosurgery, Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, United States
- University of Queensland, Brisbane, QLD, Australia
| | - Elisabeth Pechriggl
- Department of Anatomy, Histology and Embryology, Institute of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Jose Sañudo
- Department of Anatomy and Embryology, University Complutense of Madrid, Madrid, Spain
| |
Collapse
|
18
|
Theos A, Bogdanis GC, Jansson D, Nevill AM, Papaspyrou A, Maridaki M. Oxygen Uptake in Repeated Cycling Sprints Against Different Loads Is Comparable Between Men and Preadolescent Boys. Front Physiol 2022; 13:814056. [PMID: 35360252 PMCID: PMC8963450 DOI: 10.3389/fphys.2022.814056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Children recover faster than adults in repeated sprints, but it is unclear if their aerobic responses differ.PurposeThis study tested the hypothesis that aerobic response (VO2) during repeated sprints is greater in preadolescent boys than in men. Further, this study compared normalization with conventional ratio-scaling and scaling with the use of body mass (BM) as a covariate.MethodsNine boys (age: 11.8 ± 0.6 years, swimmers) and 11 men (age: 21.7 ± 0.6 years, recreational athletes) performed 10 maximal 6-s cycling sprints separated by 24-s of passive recovery, against two loads (optimum and 50% of optimum). Oxygen uptake (VO2) was measured continuously.ResultsMen’s mean power output (MPO) was greater than boys in each sprint, both in absolute (unscaled) values ( p < 0.05) and when adjusted for lean leg volume ( p < 0.05). Children had lower absolute VO2 ( p < 0.05) than men, but when it was adjusted for BM or power-output, VO2 was comparable between men and boys. Thus, most of the difference in VO2 between men and boys was due to body size and power-output differences.ConclusionOur results suggest that men and boys have similar VO2 during repeated sprints when appropriately adjusted to body mass or power output. Results highlight the importance of using appropriate scaling methods to compare adults’ and children’s aerobic responses to high-intensity exercise.
Collapse
Affiliation(s)
- Apostolos Theos
- Section of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
- Umeå School of Sport Sciences, Umeå University, Umeå, Sweden
- *Correspondence: Apostolos Theos,
| | - Gregory C. Bogdanis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Daniel Jansson
- Section of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden
- Umeå School of Sport Sciences, Umeå University, Umeå, Sweden
| | - Alan M. Nevill
- Faculty of Education Health and Wellbeing, Wolverhampton University, Wolverhampton, United Kingdom
| | - Aggeliki Papaspyrou
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Maridaki
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
19
|
Reliability, Validity, and Performance Characteristics of Elite Adolescent Athletes at Different Stages of Maturity in the 10 to 5 Repeated Jump Test. Pediatr Exerc Sci 2022; 34:20-27. [PMID: 34517340 DOI: 10.1123/pes.2020-0270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 06/01/2021] [Accepted: 07/06/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE To examine the reliability, validity, and performance characteristics of the 10 to 5 repeated jump test (10-5 RJT) in adolescent male athletes. The 10-5 RJT has been shown to be a valid and reliable test of reactive strength index (RSI) in older adolescents (age 17-19 y), but less is known in younger adolescent athletes at different stages of maturity. METHODS Athletes (age 11-17 y) completed the 10-5 RJT on 2 days, 1 week apart, to examine the reliability (n = 41), validity (n = 18) of the test. Athletes were classified as pre, circa, or post peak height velocity (PHV) height velocity using maturity offset to examine the effect of maturation status on RSI, flight time (FT), ground contact time (GCT), and jump height (JH) (n = 68) using a cross-sectional design. RESULTS Paired samples t tests showed no significant differences (P ≥ .05), and Bland-Altman analysis showed no bias and close limits of agreement for RSI, JH, FT, and GCT between the contact mat and force plate. Interday reliability was rated excellent for RSI (intraclass correlation coefficient = .91) and good for GCT, FT, and JH (intraclass correlation coefficient = .81-.85). All variables had a coefficient of variation ≤ 10%. RSI increased across maturation groups, with significant differences between pre-PHV and post-PHV groups (P = .014, d = 1.00). CONCLUSION The 10-5 RJT is a valid and reliable test for adolescent male athletes. Greater RSI with advancing maturity was primarily due to increased FT and JH, with GCT remaining similar.
Collapse
|
20
|
Abstract
The purpose of our review was to compare the distribution of motor unit properties across human muscles of different sizes and recruitment ranges. Although motor units can be distinguished based on several different attributes, we focused on four key parameters that have a significant influence on the force produced by muscle during voluntary contractions: the number of motor units, average innervation number, the distributions of contractile characteristics, and discharge rates within motor unit pools. Despite relatively few publications on this topic, current data indicate that the most influential factor in the distribution of these motor unit properties between muscles is innervation number. Nonetheless, despite a fivefold difference in innervation number between a hand muscle (first dorsal interosseus) and a lower leg muscle (tibialis anterior), the general organization of their motor unit pools, and the range of discharge rates appear to be relatively similar. These observations provide foundational knowledge for studies on the control of movement and the changes that occur with aging and neurological disorders.
Collapse
Affiliation(s)
- Jacques Duchateau
- Laboratory of Applied Biology and Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado
| |
Collapse
|
21
|
Apibantaweesakul S, Omura S, Qi W, Shiotani H, Evangelidis PE, Sado N, Tanaka F, Kawakami Y. Characteristics of inhomogeneous lower extremity growth and development in early childhood: a cross-sectional study. BMC Pediatr 2021; 21:552. [PMID: 34872516 PMCID: PMC8647383 DOI: 10.1186/s12887-021-02998-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Early childhood is a transferring stage between the two accelerated growth periods (infant and adolescent). Body dimensions are related to physical growth and development. The purpose of this study was to investigate physical growth in terms of anthropometry, muscle growth of the lower extremity, and functional development over early childhood. METHODS A cross-sectional study was carried out on 29 preschool children (PS: 3-5 years), 21 school children (SC: 6-8 years), and 22 adults (AD: 20-35 years). Lower extremity characteristics (segmental dimensions, muscle and adipose tissue thicknesses of the thigh and lower leg), and voluntary joint torque (knee and ankle) were measured. Correlations between parameters and group comparisons were performed. RESULTS All the parameters except for body mass index (BMI) and subcutaneous adipose tissue thickness were correlated with age for PS and SC combined (r = 0.479-0.920, p < 0.01). Relative thigh and shank lengths to body height were greatest in AD and smallest in PS (p < 0.05) but the relative foot dimensions were significantly larger in PS and SC than in AD (p < 0.05). Relative subcutaneous adipose tissue thickness was largest in PS and lowest in AD. Muscle thickness and the muscle volume measure (estimated from muscle thickness and limb length) were significantly larger in older age groups (p < 0.05). All groups showed comparable muscle thickness when normalized to limb length. Joint torque normalized to estimated muscle volume was greatest for AD, followed by SC and PS (p < 0.05). CONCLUSIONS Relative lower extremity lengths increase with age, except for the foot dimensions. Muscle size increases with age in proportion to the limb length, while relative adiposity decreases. Torque-producing capacity is highly variable in children and rapidly develops toward adulthood. This cross-sectional study suggests that children are not a small scale version of adults, neither morphologically nor functionally.
Collapse
Affiliation(s)
- Sudarat Apibantaweesakul
- Graduate School of Sport Sciences, Waseda University, Saitama, 359-1192, Japan
- Department of Sports Science and Sports Development, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, 12121, Thailand
| | - Shiho Omura
- Graduate School of Sport Sciences, Waseda University, Saitama, 359-1192, Japan
| | - Weihuang Qi
- Waseda Institute for Sport Sciences, Waseda University, Saitama, 359-1192, Japan
| | - Hiroto Shiotani
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan
- Human Performance Laboratory, Comprehensive Research Organization, Waseda University, Saitama, 359-1192, Japan
| | - Pavlos E Evangelidis
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan
| | - Natsuki Sado
- Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, 305-8574, Japan
| | - Fumiko Tanaka
- Human Performance Laboratory, Comprehensive Research Organization, Waseda University, Saitama, 359-1192, Japan
| | - Yasuo Kawakami
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan.
- Human Performance Laboratory, Comprehensive Research Organization, Waseda University, Saitama, 359-1192, Japan.
| |
Collapse
|
22
|
McCastlain K, Howell CR, Welsh CE, Wang Z, Wilson CL, Mulder HL, Easton J, Mertens AC, Zhang J, Yasui Y, Hudson MM, Robison LL, Kundu M, Ness KK. The Association of Mitochondrial Copy Number With Sarcopenia in Adult Survivors of Childhood Cancer. J Natl Cancer Inst 2021; 113:1570-1580. [PMID: 33871611 PMCID: PMC8562958 DOI: 10.1093/jnci/djab084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/07/2021] [Accepted: 04/14/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Adult childhood cancer survivors are at risk for frailty, including low muscle mass and weakness (sarcopenia). Using peripheral blood mitochondrial DNA copy number (mtDNAcn) as a proxy for functional mitochondria, this study describes cross-sectional associations between mtDNAcn and sarcopenia among survivors. METHODS Among 1762 adult childhood cancer survivors (51.6% male; median age = 29.4 years, interquartile range [IQR] = 23.3-36.8), with a median of 20.6 years from diagnosis (IQR = 15.2-28.2), mtDNAcn estimates were derived from whole-genome sequencing. A subset was validated by quantitative polymerase chain reaction and evaluated cross-sectionally using multivariable logistic regression for their association with sarcopenia, defined by race-, age-, and sex-specific low lean muscle mass or weak grip strength. All statistical tests were 2-sided. RESULTS The prevalence of sarcopenia was 27.0%, higher among female than male survivors (31.5% vs 22.9%; P < .001) and associated with age at diagnosis; 51.7% of survivors with sarcopenia were diagnosed ages 4-13 years (P = .01). Sarcopenia was most prevalent (39.0%) among central nervous system tumor survivors. Cranial radiation (odds ratio [OR] = 1.84, 95% confidence interval [CI] = 1.32 to 2.59) and alkylating agents (OR = 1.34, 95% CI = 1.04 to 1.72) increased, whereas glucocorticoids decreased odds (OR = 0.72, 95% CI = 0.56 to 0.93) of sarcopenia. mtDNAcn decreased with age (β = -0.81, P = .002) and was higher among female survivors (β = 9.23, P = .01) and among survivors with a C allele at mt.204 (β = -17.9, P = .02). In adjusted models, every standard deviation decrease in mtDNAcn increased the odds of sarcopenia 20% (OR = 1.20, 95% CI = 1.07 to 1.34). CONCLUSIONS A growing body of evidence supports peripheral blood mtDNAcn as a biomarker for adverse health outcomes; however, this study is the first to report an association between mtDNAcn and sarcopenia among childhood cancer survivors.
Collapse
Affiliation(s)
- Kelly McCastlain
- Department of Pathology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Carrie R Howell
- Department of Preventive Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Catherine E Welsh
- Department of Mathematics & Computer Science, Rhodes College, Memphis, TN, USA
| | - Zhaoming Wang
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Carmen L Wilson
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Heather L Mulder
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - John Easton
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Ann C Mertens
- Aflac Cancer & Blood Disorders Center at Children’s Healthcare of Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Jinghui Zhang
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Yutaka Yasui
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Melissa M Hudson
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Leslie L Robison
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Mondira Kundu
- Department of Pathology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Kirsten K Ness
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
| |
Collapse
|
23
|
Leichsenring K, Viswanathan A, Kutschke S, Siebert T, Böl M. Age-dependent mechanical and microstructural properties of the rabbit soleus muscle. Acta Biomater 2021; 134:453-465. [PMID: 34343717 DOI: 10.1016/j.actbio.2021.07.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/26/2022]
Abstract
During growth there are serious changes in the skeletal muscles to compensate for the changed requirements in terms of body weight and size. In this study, the age-dependent (between 21 and 100 days) mechanical and microstructural properties of rabbit soleus muscle tissue were investigated. For this purpose, morphological properties (animal mass, soleus muscle mass, tibial length) were measured at 5 different times during aging. On the other hand, fibre orientation-dependent axial and semi-confined compression experiments were realised. In addition, the essential components (muscle fibres, extracellular matrix, remaining components), dominating the microstructure of muscle tissue, were analysed. While the mechanical results show hardly any age-dependent differences, the morphological and microstructural results show clear age-dependent differences. All morphological parameters increase significantly (animal mass by 839.2%, muscle mass 1050.6%, tibial length 233.6%). In contrast, microstructural parameters change differently. The percentage of fibres (divided into slow-twitch (ST) and fast-twitch (FT) fibres) increases significantly (137.6%), while the proportions of the extracellular matrix and the remaining components (48.2% and 46.1%) decrease. At the same time, the cross-sectional area of the fibres increases significantly (697.9%). The totality of this age-dependent information provides a deeper understanding of age-related changes in muscle structure and function and may contribute to successful development and validation of growth models in the future. STATEMENT OF SIGNIFICANCE: This article reports the first comprehensive data set on age-dependent morphological (animal mass, soleus muscle mass, tibial length), mechanical (axial and semi-confined compression), and microstructural (muscle fibres, extracellular matrix, remaining components) properties of the rabbit soleus muscle. On the one hand, the results of this study contribute to the understanding of muscle mechanics and thus to understanding of load transfer mechanisms inside the muscle tissue during growth. On the other hand, these results are relevant to the fields of constitutive formulation of age-dependent muscle tissue.
Collapse
|
24
|
Liegnell R, Wessman F, Shalabi A, Harringe M. Validity of ultrasonography-derived predictions for estimating skeletal muscle volume: a systematic literature review. BMC Med Imaging 2021; 21:106. [PMID: 34229618 PMCID: PMC8258927 DOI: 10.1186/s12880-021-00638-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/29/2021] [Indexed: 11/11/2022] Open
Abstract
Background The amount of muscle volume (MV) varies between individuals and is important for health, well-being and performance. Therefore, the monitoring of MV using different imaging modalities is important. Magnetic resonance imaging (MRI) is considered the gold standard, but is not always easily accessible, and the examinations are expensive. Ultrasonography (US) is a much less expensive imaging method widely used to measure changes in muscle thickness (MT). Whether MT may translate into MV needs further investigation. Purpose The aim of this review is to clarify whether US-derived equations based on MT predict MV based on MRI. Methods A systematic literature review was conducted according to the PRISMA statement, searching the electronic databases PubMed, CINAHL and Web of Science, for currently published equations to estimate MV with US. Results The literature search resulted in 363 citations. Twelve articles met the eligibility criteria. Ten articles scored eight out of eleven on QUADAS and two scored nine. Thirty-six prediction equations were identified. R values ranged between 0.53 and 0.961 and the standard error of the estimate (SEE) ranged between 6 and 12% for healthy adult populations, and up to 25.6% for children with cerebral palsy. Eight studies evaluated the results with a Bland–Altman plot and found no systematic errors. The overall strength and quality of the evidence was rated “low quality” as defined by the GRADE system. Conclusions The validity of US-derived equations based on MT is specific to the populations from which it is developed. The agreement with MV based on MRI is moderate with the SEE ranging between 6 and 12% in healthy adult populations. Suggestions for future research include investigations as to whether testing positions or increasing the number of measuring sites could improve the validity for prediction equations.
Collapse
Affiliation(s)
- Rasmus Liegnell
- Stockholm Sports Trauma Research Centre, Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden.
| | - Fredrik Wessman
- Stockholm Sports Trauma Research Centre, Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| | - Adel Shalabi
- Centre for Medical Imaging, University Hospital, Uppsala University, Uppsala, Sweden
| | - Marita Harringe
- Stockholm Sports Trauma Research Centre, Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| |
Collapse
|
25
|
Dotan R, Woods S, Contessa P. On the reliability and validity of central fatigue determination. Eur J Appl Physiol 2021; 121:2393-2411. [PMID: 33966110 DOI: 10.1007/s00421-021-04700-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/24/2021] [Indexed: 11/30/2022]
Abstract
Physical performance fatigue can be ascribed to both peripheral and central components. Central fatigue, however, is an elusive entity, consisting of cognitive/sensory component and presumably also a neuro-physiological component that are difficult to tease apart and assess independently of each other. The most widely accepted method for the assessment of central fatigue is based on the premise that decreasing volitional muscle activation (VA), as determined by the interpolated twitch technique (ITT) in fatiguing muscles, reflects increasing central fatigue. Suffering its own shortcomings, the validity of VA determination under fatigued conditions has never been proven and is only assumed. This review presents evidence that questions ITT's reliability and validity in reflecting VA in the fatiguing muscle and, consequently, VA's validity for central fatigue assessment. Specifically highlighted is the paradox of children and endurance athletes, who share striking endurance characteristics, being claimed as more centrally fatigable than untrained adults. Further research and new directions are needed for confirming and quantifying central fatigue and teasing apart its psychologic and neuromotor components.
Collapse
Affiliation(s)
- Raffy Dotan
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada.
| | - Stacey Woods
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada
| | | |
Collapse
|
26
|
Neuromuscular Fatigue After Long-Duration Adventure Racing in Adolescent Athletes. Pediatr Exerc Sci 2021; 33:103-111. [PMID: 33958502 DOI: 10.1123/pes.2020-0201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 12/21/2020] [Accepted: 02/03/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE To characterize the acute effects of a long-duration adventure race on knee extensor (KE) fatigue and the knee functional ratio in adolescent athletes. METHODS Twenty trained male adolescents (aged 14-17 y) performed an adventure race of 68.5 km. Maximal voluntary isometric contraction (MVIC) KE and knee flexor torques were measured before and immediately after the race. Central and peripheral components of neuromuscular fatigue were quantified from the maximal voluntary activation level and the doublet peak torque (Tw100), respectively. The peak eccentric knee flexor torque to concentric KE torque ratio was also measured to determine functional ratio. RESULTS The race completion time was 05:38 (00:20) hours. Significant reductions in MVICKE (-14.7%, P < .001) and MVICKF (-17.0%, P < .01) were observed after the race. Voluntary activation level decreased by 8.3% (P < .001) while Tw100 remained unchanged. Peak eccentric knee flexor torque decreased 16.0% (P < .001) while peak concentric KE torque did not change. This resulted in a significant reduction in functional ratio (-12.0%, P < .01). CONCLUSION The adventure race induced a moderate fatigue, which was mainly explained by central factors without significant peripheral fatigue. However, particular attention should be paid to the knee muscular imbalance incurred by the race, which could increase the risk of ligament injury in adolescent athletes.
Collapse
|
27
|
Balakrishnan M, Yu SF, Chin SM, Soffar DB, Windner SE, Goode BL, Baylies MK. Cofilin Loss in Drosophila Muscles Contributes to Muscle Weakness through Defective Sarcomerogenesis during Muscle Growth. Cell Rep 2021; 32:107893. [PMID: 32697999 PMCID: PMC7479987 DOI: 10.1016/j.celrep.2020.107893] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/23/2020] [Accepted: 06/19/2020] [Indexed: 12/20/2022] Open
Abstract
Sarcomeres, the fundamental contractile units of muscles, are conserved structures composed of actin thin filaments and myosin thick filaments. How sarcomeres are formed and maintained is not well understood. Here, we show that knockdown of Drosophila cofilin (DmCFL), an actin depolymerizing factor, disrupts both sarcomere structure and muscle function. The loss of DmCFL also results in the formation of sarcomeric protein aggregates and impairs sarcomere addition during growth. The activation of the proteasome delays muscle deterioration in our model. Furthermore, we investigate how a point mutation in CFL2 that causes nemaline myopathy (NM) in humans affects CFL function and leads to the muscle phenotypes observed in vivo. Our data provide significant insights to the role of CFLs during sarcomere formation, as well as mechanistic implications for disease progression in NM patients. How sarcomeres are added and maintained in a growing muscle cell is unclear. Balakrishnan et al. observed that DmCFL loss in growing muscles affects sarcomere size and addition through unregulated actin polymerization. This results in a collapse of sarcomere and muscle structure, formation of large protein aggregates, and muscle weakness.
Collapse
Affiliation(s)
- Mridula Balakrishnan
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA; Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Shannon F Yu
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Samantha M Chin
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454, USA
| | - David B Soffar
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Stefanie E Windner
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454, USA
| | - Mary K Baylies
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA; Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| |
Collapse
|
28
|
Bax AM, Amiaka CO, Falk B, Gabriel DA, Tokuno CD. The effect of acute low-load resistance exercise with the addition of blood flow occlusion on muscle function in boys and men. Eur J Appl Physiol 2021; 121:2177-2185. [PMID: 33864494 DOI: 10.1007/s00421-021-04687-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 04/08/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE In adults, low-load resistance training with blood flow occlusion (BFO) mimics strength increases that occur from high-load training, without the need to experience high mechanical stress. In view of child-adult differences in exercise responses, this study examined whether BFO during exercise elicits differential changes in maximal voluntary contraction (MVC) and electromyographical (EMG) activity in children and adults. METHODS Sixteen men (24.4 ± 2.5 years) and 14 boys (10.7 ± 2.0 years) performed low-load resistance exercise (25 repetitions at 35% MVC) of the wrist flexors with and without BFO. MVC wrist flexor force and EMG activity of the flexor carpi radialis (FCR) were obtained at the beginning and end of the exercise. RESULTS Both groups demonstrated a larger decrease in MVC force following BFO (- 18.6 ± 12.5%) than the control (without BFO) condition (- 6.2 ± 15.0%; p < 0.001). Whereas the men's EMG amplitude increased 16.3 ± 20.5% (p = 0.005) during BFO, the boys' EMG amplitude did not change over time or between conditions. In both groups, the mean power frequency (MPF) of the EMG signal decreased more during BFO (- 20.1 ± 9.6%; p < 0.001) than the control condition (- 5.6 ± 9.7%; p = 0.002). CONCLUSIONS Low-load exercise with BFO resulted in similar neuromuscular responses between boys and men, except for an observed increase in the EMG amplitude in men but not boys. While this result might suggest that men relied on a greater activation of higher-threshold motor units during BFO, it does not explain why there were similar decreases in MPF between groups. Therefore, it remains unclear whether the effectiveness of BFO training is similar for children and adults.
Collapse
Affiliation(s)
- Alyssa M Bax
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Chimerem O Amiaka
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Bareket Falk
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
- Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada
| | - David A Gabriel
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Craig D Tokuno
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| |
Collapse
|
29
|
Esbjörnsson ME, Dahlström MS, Gierup JW, Jansson EC. Muscle fiber size in healthy children and adults in relation to sex and fiber types. Muscle Nerve 2021; 63:586-592. [PMID: 33347630 PMCID: PMC8048954 DOI: 10.1002/mus.27151] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 12/12/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND In adult males, cross-sectional area (CSA) for type II muscle fibers is generally larger than for type I fibers. In this cross-sectional study the aim was to compare sex-related CSAs of various muscle fiber types during childhood-to-adulthood transition. METHODS Percutaneous biopsy samples were obtained from vastus lateralis in 10-y-old children (10 males and 5 females) and in young adults (9 males and 7 females). Fiber types were classified by myofibrillar ATPase and CSAs from NADH-dehydrogenase staining. RESULTS Type IIA were larger than type I fibers in adult males, but not in adult females or children (age x sex x fiber type, P < .002). When including all participants, body weight and sex explained 78% of the variation in type IIA CSA but only body weight contributed for type I. CONCLUSIONS Sex-specific patterns in CSA of the muscle fiber types appears to develop during the transition from childhood to adulthood.
Collapse
Affiliation(s)
- Mona E Esbjörnsson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.,Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | | | | | - Eva Ch Jansson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.,Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
30
|
Shoepe TC, LaBrie JW, Mello GT, Leggett AG, Almstedt HC. Intensity of resistance training via self-reported history is critical in properly characterizing musculoskeletal health. BMC Musculoskelet Disord 2020; 21:729. [PMID: 33172425 PMCID: PMC7654594 DOI: 10.1186/s12891-020-03753-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 10/28/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Intensity of resistance training history might be omitted or poorly ascertained in prescreening or data questionnaires involving musculoskeletal health. Failure to identify history of high-versus low-intensity training may overlook higher effect sizes with higher intensities and therefore diminish the precision of statistical analysis with resistance training as a covariate and bias the confirmation of baseline homogeneity for experimental group designation. The purpose was to determine the degree to which a single question assessing participant history of resistance training intensity predicted differences in musculoskeletal health. METHODS In the first research aim, participants were separated into groups with a history (RT) and no history (NRT) of resistance training. The second research aim evaluated the history of resistance training intensity on muscular strength, lean mass, and bone mineral density (BMD), RT participants were reassigned into a low- (LIRT) or high-intensity resistance training group (HIRT). 83 males and 87 females (19.3 ± 0.6 yrs., 171.1 ± 9.9 cm, 67.1 ± 10.5 kg, 22.9 ± 2.8 BMI, 26.2 ± 7.2% body fat) completed handgrip dynamometry (HG) and dual-energy x-ray absorptiometry scans (DXA) for BMD and bone mineral-free lean mass (BFLM). RESULTS A 3-group method (NRT, LIRT, HIRT) reduced type-I error compared with the 2-group method (NRT, RT) in characterizing the likely effects of one's history of resistance training. For the second aim, HIRT had significantly (p < 0.05) greater HG strength (76.2 ± 2.2 kg) and arm BFLM (6.10 ± 0.16 kg) than NRT (67.5 ± 1.3 kg; 4.96 ± 0.09 kg) and LIRT (69.7 ± 2.0 kg; 5.42 ± 0.14 kg) while also showing significantly lower muscle quality (HG/BFLM) than NRT (13.9 ± 0.2 vs. 12.9 ± 0.3). HIRT had greater BMD at all sites compared to NRT (whole body = 1.068 ± 0.008 vs. 1.120 ± 0.014; AP spine = 1.013 ± 0.011 vs. 1.059 ± 0.019; lateral spine = 0.785 ± 0.009 vs. 0.846 ± 0.016; femoral neck = 0.915 ± 0.013 vs. 0.970 ± 0.022; total hip = 1.016 ± 0.012 vs. 1.068 ± 0.021 g/cm2) while LIRT revealed no significant skeletal differences to NRT. CONCLUSIONS Retrospective identification of high-intensity history of resistance training appears critical in characterizing musculoskeletal health and can be ascertained easily in as little as a single, standalone question. Both retrospective-questionnaire style investigations and pre-screening for potential participation in prospective research studies should include participant history of resistance training intensity.
Collapse
Affiliation(s)
- Todd C Shoepe
- Health and Human Performance Laboratory, Department of Health and Human Sciences, Loyola Marymount University, Life Sciences Building 181, 1 LMU Drive, MS 8888, Los Angeles, CA, 90045, USA.
| | - Joseph W LaBrie
- Department of Psychology, Loyola Marymount University, Los Angeles, CA, USA
| | - Grant T Mello
- Department of Psychology, Loyola Marymount University, Los Angeles, CA, USA
| | - Allison G Leggett
- Health and Human Performance Laboratory, Department of Health and Human Sciences, Loyola Marymount University, Life Sciences Building 181, 1 LMU Drive, MS 8888, Los Angeles, CA, 90045, USA
| | - Hawley C Almstedt
- Health and Human Performance Laboratory, Department of Health and Human Sciences, Loyola Marymount University, Life Sciences Building 181, 1 LMU Drive, MS 8888, Los Angeles, CA, 90045, USA
| |
Collapse
|
31
|
Hill C, James RS, Cox VM, Seebacher F, Tallis J. Age-related changes in isolated mouse skeletal muscle function are dependent on sex, muscle, and contractility mode. Am J Physiol Regul Integr Comp Physiol 2020; 319:R296-R314. [DOI: 10.1152/ajpregu.00073.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The present study aimed to simultaneously examine the age-related, muscle-specific, sex-specific, and contractile mode-specific changes in isolated mouse skeletal muscle function and morphology across multiple ages. Measurements of mammalian muscle morphology, isometric force and stress (force/cross-sectional area), absolute and normalized (power/muscle mass) work-loop power across a range of contractile velocities, fatigue resistance, and myosin heavy chain (MHC) isoform concentration were measured in 232 isolated mouse (CD-1) soleus, extensor digitorum longus (EDL), and diaphragm from male and female animals aged 3, 10, 30, 52, and 78 wk. Aging resulted in increased body mass and increased soleus and EDL muscle mass, with atrophy only present for female EDL by 78 wk despite no change in MHC isoform concentration. Absolute force and power output increased up to 52 wk and to a higher level for males. A 23–36% loss of isometric stress exceeded the 14–27% loss of power normalized to muscle mass between 10 wk and 52 wk, although the loss of normalized power between 52 and 78 wk continued without further changes in stress ( P > 0.23). Males had lower power normalized to muscle mass than females by 78 wk, with the greatest decline observed for male soleus. Aging did not cause a shift toward slower contractile characteristics, with reduced fatigue resistance observed in male EDL and female diaphragm. Our findings show that the loss of muscle quality precedes the loss of absolute performance as CD-1 mice age, with the greatest effect seen in male soleus, and in most instances without muscle atrophy or an alteration in MHC isoforms.
Collapse
Affiliation(s)
- Cameron Hill
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
- Randall Centre for Cell and Molecular Biophysics, Guy’s Campus, King’s College London, London, United Kingdom
| | - Rob S. James
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
| | - Val. M. Cox
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
| | - Frank Seebacher
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Jason Tallis
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
| |
Collapse
|
32
|
Matsumoto H, Kawakami N, Saito T, Uno K, Suzuki T, Watanabe K, Matsumoto M, Yamaguchi T, Yanagida H, Kotani T, Demura S, Takeshita K, Taniguchi Y. Short fusion with vertebrectomy during growth in congenital spinal deformity: is early surgical intervention recommended? Spine Deform 2020; 8:733-742. [PMID: 32109312 DOI: 10.1007/s43390-020-00082-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/05/2020] [Indexed: 11/28/2022]
Abstract
STUDY DESIGN This was a multi-center retrospective cohort study included consecutive pediatric patients who were admitted to 8 institutions for the treatment of congenital spinal deformity from 1991 to 2012. OBJECTIVE The purpose of this study was to compare curve corrections and balances, reoperations, and complications at 2-year follow-up between those treated early vs. late. Although early intervention has been recommended, no empirical study has examined the optimal timing of short fusion among patients with congenital spinal deformity. METHODS Patients with congenital spinal deformity with formation failure undergoing vertebrectomy with short fusion (≤ 6 fusion segments) were categorized as early (surgery at ≤ 6 years) and late (7-18 years) fusion. Outcomes included coronal and sagittal curve corrections at immediate and 2-year evaluations; loss of curve correction from immediate to 2-year follow-up; coronal and sagittal balance at 2 years; and inter-operative, major and minor short-term postoperative, and long-term postoperative complications and reoperations. RESULTS Early fusion (N = 79) compared to late fusion (N = 96) was associated with greater percent curve correction at immediate (71% vs. 60%, p = 0.0046) and 2-year (63% vs. 52%, p = 0.0153) evaluations adjusting for surgeon experience and preoperative coronal balance. These associations were significant for males and those with 3-level fusions but not 4 to 6-level fusions. Early fusion compared with late fusion had more intraoperative (6% vs. 1%) and postoperative long-term complications (27% vs. 18%), as well as unplanned reoperations (13% vs. 9%). Early vs. late fusion had fewer short-term complications, both major (6% vs. 15%) and minor (6% vs. 15%). CONCLUSIONS Patients who underwent early treatment achieved larger major curve correction by 10% compared to patients with late treatment when assessed at 2-year postoperative evaluation. However, early fusion should be considered with careful attention to possible increased risk of reoperations. LEVEL OF EVIDENCE Level III.
Collapse
Affiliation(s)
- Hiroko Matsumoto
- Division of Pediatric Orthopaedic Surgery, Department of Orthopaedic Surgery, Columbia University Medical Center, Department of Epidemiology, Mailman School of Public Health, Columbia University, 3959 Broadway, Suite 800 North, New York, NY, 10032, USA
| | - Noriaki Kawakami
- Department of Orthopaedic and Spine Surgery, Meijyo Hospital, Sannomaru, 1-3-1, Naka-ku, Nagoya, Aichi, 460-0001, Japan.
| | - Toshiyuki Saito
- Department of Orthopaedic and Spine Surgery, Meijyo Hospital, Sannomaru, 1-3-1, Naka-ku, Nagoya, Aichi, 460-0001, Japan
| | - Koki Uno
- Department of Orthopaedic Surgery, Kobe Medical Center, 3-1-1 Nishiochiai Suma-ku, Kobe, Hyogo, 654-0155, Japan
| | - Teppei Suzuki
- Department of Orthopaedic Surgery, Kobe Medical Center, 3-1-1 Nishiochiai Suma-ku, Kobe, Hyogo, 654-0155, Japan
| | - Kota Watanabe
- Department of Orthopaedic Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo, 160-0016, Japan
| | - Morio Matsumoto
- Department of Orthopaedic Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo, 160-0016, Japan
| | - Toru Yamaguchi
- Department of Orthopaedic Surgery, Fukuoka Children's Hospital, 5-1-1 Kashiiteriha, Higishi-ku, Fukuoka, Fukuoka, 813-0017, Japan
| | - Haruhisa Yanagida
- Department of Orthopaedic Surgery, Fukuoka Children's Hospital, 5-1-1 Kashiiteriha, Higishi-ku, Fukuoka, Fukuoka, 813-0017, Japan
| | - Toshiaki Kotani
- Department of Orthopaedic Surgery, Seirei Sakura City Hospital, 2-36-2 Ebaradai, Sakura, Chiba, 285-0825, Japan
| | - Satoru Demura
- Department of Orthopaedic Surgery, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Katsushi Takeshita
- Department of Orthopaedic Surgery, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Yuki Taniguchi
- Department of Orthopaedic Surgery, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8654, Japan
| |
Collapse
|
33
|
Shoepe TC, McCormack WP, LaBrie JW, Mello GT, Almstedt HC. Indicators of Sarcopenia: Sex Differences in Competitive Runners Prior to Peak Muscle Mass. Int J Sports Med 2020; 41:1067-1076. [PMID: 32722828 DOI: 10.1055/a-1202-1663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Strength, muscle mass, and muscle quality have been observed to be compromised in low body-mass index individuals such as competitive runners, increasing their risk for sarcopenia. The purpose was to compare indices of sarcopenia in young runners to age, height, body-mass, and body-mass index-matched non-runners. Handgrip strength and arm composition from dual-energy x-ray absorptiometry (baseline-T1, T2=5.3±1.4, T3=11.5±0.7 months later) were assessed in 40 non-runners and 40 runners (19.3±0.7 vs. 19.2±1.1 years, 170.7±10.3 vs. 171.1±9.1 cm, 60.2±7.4 vs. 60.2±7.9 kg, 20.6±0.9 vs. 20.5±1.5 kg m-2). The unitless variable of muscle quality, was defined as the sum of right and left maximal handgrip (in kg) divided by the sum of bone-free lean mass of both arms (in kg). Female runners displayed the highest muscle quality (T1=15.3±1.7; T3=15.7±2.0) compared to male runners (T1=13.7±1.4, p < 0.001; T3=14.2±1.6, p < 0.001) and male non-runners (T1=12.4±1.8, p=0.001; T3=13.2±1.6, p < 0.001), while female non-runners (T1=14.6±2.5, p=0.154; T3=15.1 ±2.2, p=0.124) showed higher muscle quality than male non-runners. Higher muscle quality in low-body-mass index females persists over one-year during young-adulthood and while running contributes to whole-body muscle mass accrual, it does not appear to be significantly associated with improvements in the most commonly used upper-body diagnostic indicator of sarcopenia.
Collapse
Affiliation(s)
- Todd C Shoepe
- Health and Human Sciences, Loyola Marymount University Frank R Seaver College of Science and Engineering, Los Angeles, United States
| | - William P McCormack
- Health and Human Sciences, Loyola Marymount University Frank R Seaver College of Science and Engineering, Los Angeles, United States
| | - Joseph W LaBrie
- Health and Human Sciences, Loyola Marymount University, Los Angeles, United States
| | - Grant T Mello
- Health and Human Sciences, Loyola Marymount University Frank R Seaver College of Science and Engineering, Los Angeles, United States
| | - Hawley C Almstedt
- Health and Human Sciences, Loyola Marymount University Frank R Seaver College of Science and Engineering, Los Angeles, United States
| |
Collapse
|
34
|
Backward Running: Acute Effects on Sprint Performance in Preadolescent Boys. Sports (Basel) 2020; 8:sports8040055. [PMID: 32340126 PMCID: PMC7240527 DOI: 10.3390/sports8040055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/12/2020] [Accepted: 04/20/2020] [Indexed: 11/17/2022] Open
Abstract
The aim of this study was to examine the acute effect of backward running (BwR) during warm-up on a 20-m sprint of boys’ performance, compared to forward running (FwR). Fourteen recreationally active preadolescent boys (aged 12.5 ± 0.5 years) were examined in 3 protocols: warm-up (control condition), warm-up with 3 × 10 m additional BwR sprints and warm-up with 3 × 10 m additional FwR sprints. Participants were evaluated 4 minutes after each protocol on a 20-m sprint and intermediate distances, as well as the rate of perceived exertion (RPE). Sprint speed across 10-20 m was significantly higher for the BwR warm-up compared to the regular warm-up (p < 0.05) and a significantly higher RPE after the BwR and FwR protocols compared to the control condition was recorded (p < 0.05). No significant difference was detected across the distances 0–5, 5–10, 0–10 and 0–20 m. Although adding 3 × 10-m sprints of BwR or FwR after the warm-up did not enhance performance in a 20 m sprint of preadolescent boys, the positive effect of BwR across 10–20 m distance suggests that BwR could be an alternative means for enhancing performance for certain phases of a sprint for this age. However, preadolescent boys’ response to different sprint conditioning exercise stimuli and the optimization of rest time to maximize performance remain to be determined.
Collapse
|
35
|
Birat A, Bourdier P, Dodu A, Grossoeuvre C, Blazevich AJ, Amiot V, Dupont AC, Nottin S, Ratel S. Effect of Long-Duration Adventure Races on Cardiac Damage Biomarker Release and Muscular Function in Young Athletes. Front Physiol 2020; 11:10. [PMID: 32116738 PMCID: PMC7012902 DOI: 10.3389/fphys.2020.00010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/10/2020] [Indexed: 11/13/2022] Open
Abstract
The aim of the present study was to examine the effect of 1- and 2-day adventure races on cardiac muscle damage and skeletal muscle soreness and function in young athletes. Twelve male trained adolescents (14-15 years) completed both 1-day (48.2 km) and 2-day (66.0 km) races that included trail running, mountain biking, kayaking, and in-line skating separated by 10 weeks. Myocardial damage biomarker concentrations (cTnI and CK-MB), maximal voluntary isometric contraction (MVIC) torque, perceived knee extensor (KE) muscle soreness (PMS), and drop and squat jump heights were measured before and after each race. Heart rate was also monitored throughout. Mean heart rate (% cardiac reserve) was higher during the 1-day (66.6 ± 6.4%) than 2-day (62.6 ± 7.8%, p = 0.038) race. The amplitude of cardiac damage biomarker release was also higher following the 1-day than the 2-day race (peak cTnI: 0.14 vs. 0.03 ng/mL, p = 0.045; peak CK-MB: 20.30 vs. 11.98 ng/mL, p = 0.020). However, cardiac biomarker concentrations returned to baseline at 24-48 h post-exercise, except for CK-MB after the 2-day race (p = 0.017). Eight and three participants exceeded the cTnI cut-off for myocardial injury in 1- and 2-day races, respectively, but none exceeded the cut-off for acute myocardial infarction. While there was a significant decrease in drop jump height (-5.9%, p = 0.003), MVIC torque and squat jump height remained unchanged after both races. PMS was increased at 24 h after both races (p < 0.001) but returned to baseline levels by 72 h post-race. In conclusion, the shorter, more intense race produced more cardiac damage, although this probably represents a standard exercise intensity-dependent response rather than pathological response. Skeletal muscle functional and soreness responses were moderate and similar between races.
Collapse
Affiliation(s)
- Anthony Birat
- UFR STAPS - Laboratoire AME2P, Université Clermont Auvergne, Clermont-Ferrand, France.,Fédération Française Triathlon, Saint-Denis, France
| | - Pierre Bourdier
- UFR STAPS - Laboratoire AME2P, Université Clermont Auvergne, Clermont-Ferrand, France
| | | | | | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Virgile Amiot
- Service de Médecine du Sport et d'Exploration Fonctionnelle Respiratoire, Centre Hospitalier Régional, Orléans-La-Source, France
| | - Anne-Charlotte Dupont
- Fédération Française Triathlon, Saint-Denis, France.,Imagerie Adaptative Diagnostique et Interventionnelle, CHRU de Nancy Brabois, Bâtiment Recherche, U1254 INSERM, Université de Lorraine, Nancy, France
| | - Stéphane Nottin
- Laboratoire de Pharm-Ecologie Cardiovasculaire, Avignon Université, Avignon, France
| | - Sébastien Ratel
- UFR STAPS - Laboratoire AME2P, Université Clermont Auvergne, Clermont-Ferrand, France
| |
Collapse
|
36
|
Isometric-based EMG threshold in girls and women. Eur J Appl Physiol 2020; 120:907-914. [PMID: 32124008 DOI: 10.1007/s00421-020-04331-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 02/17/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND The electromyographic threshold (EMGTh) has been suggested to indicate the onset of accelerated higher-threshold (type-II) MU recruitment. Previous research has demonstrated that boys' EMGTh occurs at higher relative exercise intensities than men's in both cycling- and isometric-based testing. Girls‒women EMGTh differences were demonstrated only in cycling, but findings were clouded by low EMGTh-detection rates in women (68%) and particularly in girls (45%) PURPOSE: To examine the EMGTh, in girls and women, using the same males-employed isometric-based test protocol, and compare the females' findings with those previously obtained in the males. METHODS Seventeen girls and 17 women had their EMGTh determined as well as their one-repetition-maximum isometric knee-extension strength (1RM). Vastus-lateralis sEMG root mean square was recorded and the EMGTh was defined as the exercise intensity (%1RM) at the bi-segmental point of the least sum of squares. RESULTS EMGTh was detected in 88.2% of girls and 94.1% of women and occurred at higher relative intensities in the girls than in women (56.0 ± 11.1 vs. 47.7 ± 8.0% 1RM). The girls' 1RM (normalized to lean body mass) was only 69.1% that of the women. CONCLUSIONS Girls' EMGTh values are higher compared with women's, possibly reflecting lower ability to activate higher-threshold (type-II) motor units. The females' EMGTh and detection-rate values were similar to the corresponding values previously observed in males. The females' age-related difference in the recruitment of higher-threshold motor units, as reflected by the EMGTh, appears to be on par with the males.
Collapse
|
37
|
Dantas M, Queiros VSD, Fonseca FDS, Almeida-Neto PFD, Teixeira RV, Silva LMD, Aidar FJ, Matos DGD, Cabral BGDAT. The stretch-shortening cycle efficiency is dependent on the maturational stage. REVISTA BRASILEIRA DE CINEANTROPOMETRIA E DESEMPENHO HUMANO 2020. [DOI: 10.1590/1980-0037.2020v22e72597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Abstract Maturation interferes with physiological and mechanical aspects of muscle contraction. The aim of the present study was to compare the efficiency of the stretch-shortening cycle (SSC) between different maturation stages. One hundred forty six young people, with 72 boys and 74 girls, were recruited to participate in the study. Sexual maturation was measured and the group was stratified into adolescents (> 3 auto-tanner) and children (<2 auto-tanner). Squat jump (SJ) and countermovement jump (CMJ) performance were measured to measure reactive force (RF) capacity, eccentric utilization ratio (EUR) and pre-stretch augmentation (PSAP). The children did not present statistical difference between SJ and CMJ (t(55)= -1.93; ∆ = -0.61; 95% CI = -1.24 to -0.02; p = 0.058), while the adolescents presented higher performance of CMJ (t(89)= -12.28; ∆ = -2.44; 95% CI = -2.84 to -2.05; p <0.001). In addition, adolescents had higher RF performance (t(144)= 5.18; p <0.0001; 95% CI = 2.53 to 1.13), PSAP (t(144)= 4.38; p <0.0001; 95% CI = 14.00 to 5.29) and EUR (t(144)= 4.38; p <0.0001; 95% CI = 0.14 to 0.05). We conclude that more mature young people have better SSC utilization.
Collapse
|
38
|
Ušaj A, Mekjavic IB, Kapus J, McDonnell AC, Jaki Mekjavic P, Debevec T. Muscle Oxygenation During Hypoxic Exercise in Children and Adults. Front Physiol 2019; 10:1385. [PMID: 31787903 PMCID: PMC6854007 DOI: 10.3389/fphys.2019.01385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 10/21/2019] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION While hypoxia is known to decrease peak oxygen uptake ( V . o 2 max) and maximal power output in both adults and children its influence on submaximal exercise cardiorespiratory and, especially, muscle oxygenation responses remains unclear. METHODS Eight pre-pubertal boys (age = 8 ± 2 years.; body mass (BM) = 29 ± 7 kg) and seven adult males (age = 39 ± 4 years.; BM = 80 ± 8 kg) underwent graded exercise tests in both normoxic (PiO2 = 134 ± 0.4 mmHg) and hypoxic (PiO2 = 105 ± 0.6 mmHg) condition. Continuous breath-by-breath gas exchange and near infrared spectroscopy measurements, to assess the vastus lateralis oxygenation, were performed during both tests. The gas exchange threshold (GET) and muscle oxygenation thresholds were subsequently determined for both groups in both conditions. RESULTS In both groups, hypoxia did not significantly alter either GET or the corresponding V . o 2 at GET. In adults, higher V . E levels were observed in hypoxia (45 ± 6 l/min) compared to normoxia (36 ± 6 l/min, p < 0.05) at intensities above GET. In contrast, in children both the hypoxic V . E and V . o 2 responses were significantly greater than those observed in normoxia only at intensities below GET (p < 0.01 for V . E and p < 0.05 for V . o 2). Higher exercise-related heart rate (HR) levels in hypoxia, compared to normoxia, were only noted in adults (p < 0.01). Interestingly, hypoxia per se did not influence the muscle oxygenation thresholds during exercise in neither group. However, and in contrast to adults, the children exhibited significantly higher total hemoglobin concentration during hypoxic as compared to normoxic exercise (tHb) at lower exercise intensities (30 and 60 W, p = 0.01). CONCLUSION These results suggest that in adults, hypoxia augments exercise ventilation at intensities above GET and might also maintain muscle blood oxygenation via increased HR. On the other hand, children exhibit a greater change of muscle blood perfusion, oxygen uptake as well as ventilation at exercise intensities below GET.
Collapse
Affiliation(s)
- Anton Ušaj
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Jernej Kapus
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Adam C McDonnell
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | | | - Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.,Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| |
Collapse
|
39
|
Forbregd TR, Aloyseus MA, Berg A, Greve G. Cardiopulmonary Capacity in Children During Exercise Testing: The Differences Between Treadmill and Upright and Supine Cycle Ergometry. Front Physiol 2019; 10:1440. [PMID: 31849698 PMCID: PMC6897055 DOI: 10.3389/fphys.2019.01440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/07/2019] [Indexed: 11/30/2022] Open
Abstract
Background/Hypothesis: Cardiopulmonary exercise testing (CPET) is used in the assessment of function and prognosis of cardiopulmonary health in children with cardiac and pulmonary diseases. Techniques, such as cardiac MRi, and PET-scan, can be performed simultaneously with exercise testing. Thus, it is desirable to have a broader knowledge about children’s normal cardiopulmonary function in different body postures and exercise modalities. The aim of this study was to investigate the effect of different body positions on cardiopulmonary function in healthy subjects performing CPETs. Materials and Methods: Thirty-one healthy children aged 9, 12, and 15 years did four CPETs: one treadmill test with a modified Bruce protocol and three different bicycle tests with different body postures, sitting, tilted 45°, and lying flat (0°). For the bicycle tests, a 20-watt ramp protocol with a pedal frequency of 60 ± 5 rotations per minute was used. Continous ECG and breath-by-breath V.O2 measurements was done throughout the tests. Cardiac structure and function including aortic diameter were evaluated by transthoracic echocardiography prior to the tests. Doppler measurements of the blood velocity in the ascending aorta were measured prior to and during the test. Prior to every test, the participants performed pulmonary function tests with maximum voluntary ventilation test. Results: There is a significantly (p < 0.05) lower peak V.O2 in all bicycle tests compared with the treadmill test. There is lower corrected peak V.O2 (ml kg−0.67 min−1), but not relative peak V.O2 (ml kg−1 min−1), in the supine compared with the upright bicycle test. There are no differences in peak stroke volume or cardiac output between the bicycle modalities when calculated from aortic blood flow. Peak heart rate decreases from both treadmill to upright bicycle and from upright bicycle to the supine test (0°). Conclusion: There are no differences in peak cardiac output between the upright bicycle test and supine bicycle tests. Heart rate and corrected peak V.O2 are lower in the supine test (0°) than the upright bicycle test. In the treadmill test, it is a higher absolute and relative peak V.O2. Despite the latter differences, we are convinced that both upright and supine bicycle tests are apt in the clinical setting when needed.
Collapse
Affiliation(s)
| | | | - Ansgar Berg
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Pediatrics and Adolescents Medicine, Haukeland University Hospital, Bergen, Norway
| | - Gottfried Greve
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Diseases, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
40
|
Drury B, Ratel S, Clark CC, Fernandes JF, Moran J, Behm DG. Eccentric Resistance Training in Youth: Perspectives for Long-Term Athletic Development. J Funct Morphol Kinesiol 2019; 4:E70. [PMID: 33467385 PMCID: PMC7739302 DOI: 10.3390/jfmk4040070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 02/07/2023] Open
Abstract
The purpose of this narrative review is to discuss the role of eccentric resistance training in youth and how this training modality can be utilized within long-term physical development. Current literature on responses to eccentric exercise in youth has demonstrated that potential concerns, such as fatigue and muscle damage, compared to adults are not supported. Considering the importance of resistance training for youth athletes and the benefits of eccentric training in enhancing strength, power, speed, and resistance to injury, its inclusion throughout youth may be warranted. In this review we provide a brief overview of the physiological responses to exercise in youth with specific reference to the different responses to eccentric resistance training between children, adolescents, and adults. Thereafter, we discuss the importance of ensuring that force absorption qualities are trained throughout youth and how these may be influenced by growth and maturation. In particular, we propose practical methods on how eccentric resistance training methods can be implemented in youth via the inclusion of efficient landing mechanics, eccentric hamstrings strengthening and flywheel inertia training. This article proposes that the use of eccentric resistance training in youth should be considered a necessity to help develop both physical qualities that underpin sporting performance, as well as reducing injury risk. However, as with any other training modality implemented within youth, careful consideration should be given in accordance with an individual's maturity status, training history and technical competency as well as being underpinned by current long-term physical development guidelines.
Collapse
Affiliation(s)
- Benjamin Drury
- Department of Applied Sport Sciences, Hartpury University, Gloucestershire GL19 3BE, England, UK;
| | - Sébastien Ratel
- Laboratoire des Adaptations Métaboliques à l’Exercice en conditions Physiologiques et Pathologiques (AME2P, EA 3533), Université Clermont Auvergne, F-63000 Clermont-Ferrand, France;
| | - Cain C.T. Clark
- Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5RW, England, UK;
| | - John F.T. Fernandes
- Department of Applied Sport Sciences, Hartpury University, Gloucestershire GL19 3BE, England, UK;
| | - Jason Moran
- School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Colchester CO4 3WA, UK;
| | - David G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s Newfoundland and Labrador, A1C 5S7C, Canada;
| |
Collapse
|
41
|
Chen X, Li Z, Wang Y, Liu J, Zhao D. Investigation on the Cooperative Grasping Capabilities of Human Thumb and Index Finger. Front Neurorobot 2019; 13:92. [PMID: 31749694 PMCID: PMC6848373 DOI: 10.3389/fnbot.2019.00092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 10/23/2019] [Indexed: 11/29/2022] Open
Abstract
The maximum cooperative grasping mass and diameter of the human thumb and index finger were investigated by 7560 grasp-release trials on various masses of solid cylinders and various sizes of rings. The maximum grasping mass of the participants’ thumb-index finger depended on gender, age and the sum of thumb-index finger lengths (P < 0.05), but not on the hand-used and ratio of index finger to thumb length (P > 0.05). The maximum grasping diameter of the participants’ thumb-index finger depended on the age, sum of thumb-index finger lengths and ratio of index finger to thumb length (P < 0.05), but not on the gender and hand-used (P > 0.05). There was a non-linear regression model for the dependence of the maximum grasping mass on gender, age and the sum of thumb-index finger lengths and another non-linear regression model for the dependence of the maximum grasping diameter on the age, sum of thumb-index finger lengths and ratio of index finger to thumb length. Two regression models were useful in the optimal size design of robotic hands intending to replicate thumb-index finger grasping ability. This research can help to define not only a reasonable grasp mass and size for a bionic robotic hand, but also the requirements for hand rehabilitation.
Collapse
Affiliation(s)
- Xiaojing Chen
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China.,School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, China
| | - Zhiguo Li
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Yuqing Wang
- School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, China
| | - Jizhan Liu
- School of Agricultural Equipment Engineering, Jiangsu University, Zhenjiang, China
| | - Dezong Zhao
- Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, United Kingdom
| |
Collapse
|
42
|
Peak Age and Performance Progression in World-Class Weightlifting and Powerlifting Athletes. Int J Sports Physiol Perform 2019; 14:1357-1363. [DOI: 10.1123/ijspp.2019-0093] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/08/2019] [Accepted: 03/13/2019] [Indexed: 11/18/2022]
Abstract
Purpose:To quantify age of peak performance and performance improvements in the years preceding peak age in elite weightlifting and powerlifting athletes using results from powerlifting World Championships in 2003–2017 and weightlifting World Championships and Olympic Games in 1998–2017.Methods:Individual performance trends were derived by fitting a quadratic curve separately to each athlete’s performance and age data. Effects were evaluated using magnitude-based inferences.Results:Peak age (mean [SD]) was 35 (7) y for powerlifters and 26 (3) y for weightlifters, a large most likely substantial difference of 9, ±1 y (mean, 90% confidence limit). Men showed possibly higher peak age than women in weightlifting (0.8, ±0.7 y; small) and a possibly lower peak age in powerlifting (1.3, ±1.8 y; trivial). Peak age of athletes who ever won a medal was very likely less than that of nonmedalists in weightlifting (1.3, ±0.6 y; small), while the difference in powerlifters was trivial but unclear. Five-year improvements prior to peak age were 12% (10%) for powerlifters and 9% (7%) for weightlifters, a small possibly substantial difference (2.9, ±2.1%). Women exhibited possibly greater improvements than men in powerlifting (2.7, ±3.8%; small) and very likely greater in weightlifting (3.5, ±1.6%; small). Medalists possibly improved less than nonmedalists among powerlifters (−1.7, ±2.3%; small), while the difference was likely trivial for weightlifters (2.3, ±1.8%).Conclusion:These novel insights on performance development will be useful for practitioners evaluating strategies for achieving success.
Collapse
|
43
|
Piponnier E, Martin V, Bourdier P, Biancarelli B, Kluka V, Garcia-Vicencio S, Jegu AG, Cardenoux C, Morio C, Coudeyre E, Ratel S. Maturation-related changes in the development and etiology of neuromuscular fatigue. Eur J Appl Physiol 2019; 119:2545-2555. [PMID: 31562535 DOI: 10.1007/s00421-019-04233-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/18/2019] [Indexed: 12/27/2022]
Abstract
PURPOSE The aim of the present study was to investigate the role of maturation on the etiology of neuromuscular fatigue induced by repeated maximal voluntary isometric contractions (MVIC). METHODS Nine prepubertal boys (9.9 ± 1.3 years), eight male adolescents (13.6 ± 1.3 years) and eleven men (23.4 ± 3.0 years) performed a series of repeated isometric MVICs of the knee extensors until the MVIC torque reached 60% of its initial value. Magnetic stimulations were delivered to the femoral nerve every five MVICs to follow the course of voluntary activation level (VA) and the potentiated twitch torque (Qtwpot). RESULTS Task failure was reached after 52.9 ± 12.7, 42.6 ± 12.5, and 26.6 ± 6.3 repetitions in boys, adolescents and men, respectively. VA remained unchanged in men whereas it decreased significantly and similarly in boys and adolescents (p < 0.001). In contrast, Qtwpot remained unchanged in boys and decreased significantly less in adolescents than adults (p < 0.05). CONCLUSIONS Children and adolescents experience less peripheral and more central fatigue than adults. However, adolescents experience more peripheral fatigue than children for a comparable amount of central fatigue. This finding supports the idea that the tolerance of the central nervous system to peripheral fatigue could increase during maturation.
Collapse
Affiliation(s)
- Enzo Piponnier
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France.
| | - Vincent Martin
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Pierre Bourdier
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Brice Biancarelli
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Virginie Kluka
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France.,Decathlon SportsLab, Villeneuve d'Asq, France
| | - Sebastian Garcia-Vicencio
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France.,Unité de Physiologie de l'Exercice et des Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France
| | | | | | | | - Emmanuel Coudeyre
- Clermont University Hospital, Clermont-Ferrand, France.,Université Clermont Auvergne, UNH, INRA, CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Sébastien Ratel
- Laboratoire AME2P (EA 3533), Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| |
Collapse
|
44
|
Shoemaker ME, Gillen ZM, Mckay BD, Bohannon NA, Gibson SM, Koehler K, Cramer JT. Sex-specific relationships among iron status biomarkers, athletic performance, maturity, and dietary intakes in pre-adolescent and adolescent athletes. J Int Soc Sports Nutr 2019; 16:42. [PMID: 31533743 PMCID: PMC6751686 DOI: 10.1186/s12970-019-0306-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 08/26/2019] [Indexed: 01/22/2023] Open
Abstract
Background The purpose of this study was to examine relationships among biomarkers of iron status, athletic performance, growth and development, and dietary intakes in pre-adolescent and adolescent male and female athletes. Methods Two-hundred and forty-nine male (n = 179) (mean ± standard deviation for age = 12.0 ± 2.1 years, height = 156.3 ± 13.9 cm, and weight = 49.1 ± 16.5 kg) and female (n = 70) (12.0 ± 2.2 years, 152.4 ± 12.3 cm, 45.3 ± 14.5 kg) athletes volunteered for capillary blood sample, anthropometric, athletic performance, and dietary intake assessments. Outcomes included maturity offset from peak height velocity, percent body fat, estimated muscle cross-sectional areas, vertical jump height (VJ), broad jump distance (BJ), pro-agility time (PA), L-cone time, 20-yard dash time (20YD), power push up (PPU) force, dietary intakes, and ferritin, soluble transferrin receptor (sTfR), and hemoglobin (Hb) concentrations. Results Athletic performance was consistently correlated with Hb in males (r = .237–.375, p < 0.001–0.05) and with sTfR (r = .521–.649, p < 0.001–0.004) and iron intake (r = .397–.568, p = 0.001–0.027) in females. There were no relationships between dietary intakes and ferritin, sTfR, or Hb (p > 0.05). After partialing out age and height, VJ, PA, LC, and 20YD remained correlated with Hb in males (|rHb,y.Age| = .208–.322, p = 0.001–0.041; |rHb,y.Height| = .211–.321, p = 0.001–0.038). After partialing out iron intake, PA and LC remained correlated with sTfR in females (|rsTfR,y.ironintake| = .516–.569, p = 0.014–0.028). Conclusions Iron status biomarkers demonstrated sex-specific relationships with anaerobic exercise performance in youth athletes, which may be more dependent on maturity status and dietary intake than age. Moderate relationships between sTfR and athletic performance in adolescent female athletes emphasizes the importance of iron intake in this demographic.
Collapse
Affiliation(s)
- Marni E Shoemaker
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Zachary M Gillen
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Brianna D Mckay
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Nicholas A Bohannon
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Sydney M Gibson
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Karsten Koehler
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA
| | - Joel T Cramer
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Ruth Leverton Hall, Lincoln, NE, 68583, USA.
| |
Collapse
|
45
|
Breese BC, Saynor ZL, Barker AR, Armstrong N, Williams CA. Relationship between (non)linear phase II pulmonary oxygen uptake kinetics with skeletal muscle oxygenation and age in 11-15 year olds. Exp Physiol 2019; 104:1929-1941. [PMID: 31512297 DOI: 10.1113/ep087979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do the phase II parameters of pulmonary oxygen uptake ( V ̇ O 2 ) kinetics display linear, first-order behaviour in association with alterations in skeletal muscle oxygenation during step cycling of different intensities or when exercise is initiated from an elevated work rate in youths. What is the main finding and its importance? Both linear and non-linear features of phase II V ̇ O 2 kinetics may be determined by alterations in the dynamic balance between microvascular O2 delivery and utilization in 11-15 year olds. The recruitment of higher-order (i.e. type II) muscle fibres during 'work-to-work' cycling might be responsible for modulating V ̇ O 2 kinetics with chronological age. ABSTRACT This study investigated in 19 male youths (mean age: 13.6 ± 1.1 years, range: 11.7-15.7 years) the relationship between pulmonary oxygen uptake ( V ̇ O 2 ) and muscle deoxygenation kinetics during moderate- and very heavy-intensity 'step' cycling initiated from unloaded pedalling (i.e. U → M and U → VH) and moderate to very heavy-intensity step cycling (i.e. M → VH). Pulmonary V ̇ O 2 was measured breath-by-breath along with the tissue oxygenation index (TOI) of the vastus lateralis using near-infrared spectroscopy. There were no significant differences in the phase II time constant ( τ V ̇ O 2 p ) between U → M and U → VH (23 ± 6 vs. 25 ± 7 s; P = 0.36); however, the τ V ̇ O 2 p was slower during M → VH (42 ± 16 s) compared to other conditions (P < 0.001). Quadriceps TOI decreased with a faster (P < 0.01) mean response time (MRT; i.e. time delay + τ) during U → VH (14 ± 2 s) compared to U → M (22 ± 4 s) and M → VH (20 ± 6 s). The difference (Δ) between the τ V ̇ O 2 p and MRT-TOI was greater during U → VH compared to U → M (12 ± 7 vs. 2 ± 7 s, P < 0.001) and during M → VH (23 ± 15 s) compared to other conditions (P < 0.02), suggesting an increased proportional speeding of fractional O2 extraction. The slowing of the τ V ̇ O 2 p during M → VH relative to U → M and U → VH correlated positively with chronological age (r = 0.68 and 0.57, respectively, P < 0.01). In youths, 'work-to-work' transitions slowed microvascular O2 delivery-to-O2 utilization with alterations in phase II V ̇ O 2 dynamics accentuated between the ages of 11 and 15 years.
Collapse
Affiliation(s)
- Brynmor C Breese
- School of Biomedical Sciences, Faculty of Medicine and Dentistry, University of Plymouth, Plymouth, UK
| | - Zoe L Saynor
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, UK
| | - Alan R Barker
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Neil Armstrong
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Craig A Williams
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| |
Collapse
|
46
|
Why Do Children Have Faster VO 2 Kinetics?-A Response to Dotan (2019). Pediatr Exerc Sci 2019; 31:260-261. [PMID: 30943850 DOI: 10.1123/pes.2019-0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
47
|
|
48
|
Characteristics of motor unit recruitment in boys and men at maximal and submaximal force levels. Exp Brain Res 2019; 237:1289-1302. [DOI: 10.1007/s00221-019-05508-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/04/2019] [Indexed: 10/27/2022]
|
49
|
Bontemps B, Piponnier E, Chalchat E, Blazevich AJ, Julian V, Bocock O, Duclos M, Martin V, Ratel S. Children Exhibit a More Comparable Neuromuscular Fatigue Profile to Endurance Athletes Than Untrained Adults. Front Physiol 2019; 10:119. [PMID: 30828304 PMCID: PMC6384268 DOI: 10.3389/fphys.2019.00119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 01/30/2019] [Indexed: 11/13/2022] Open
Abstract
The present study compared neuromuscular fatigue profiles between children, untrained adults and adult endurance athletes during repeated maximal muscle contractions. Eighteen prepubertal boys, 19 untrained men and 13 endurance male athletes performed 5-s maximal voluntary isometric knee extensor contractions (MVICs) interspersed with 5-s recovery until MVIC reached 60% of its initial value. Single and doublet magnetic stimulations were delivered to the femoral nerve to quantify the time course of potentiated twitch amplitude (Ttw,pot), high-frequency torque (T100 Hz) and the low-to-high frequency torque ratio (T10 Hz/T100 Hz), i.e., indicators of peripheral fatigue. M-wave-normalized EMG amplitudes (EMG/M) and the maximal voluntary activation level (VA) were calculated to quantify central fatigue. Adults (15.9 ± 3.9 repetitions) performed fewer MVICs than children (40.4 ± 19.7) and endurance athletes (51.7 ± 19.6), however, no difference was observed between children and athletes (P = 0.13). Ttw,pot (∼52%, P < 0.001), T100 Hz (∼39%, P < 0.001) and T10 Hz/T100 Hz (∼23%, P < 0.001) decreased only in adults. Similar decrements in vastus medialis and vastus lateralis EMG/M were observed in children and endurance athletes (range: 40-50%), and these were greater than in adults (∼15%). Whilst VA decreased more in children (-38.4 ± 22.5%, P < 0.001) than endurance athletes (-20.3 ± 10.1%, P < 0.001), it did not change in adults. Thus, children fatigued more slowly than adults and as much as endurance athletes. They developed less peripheral and more central fatigue than adults and, although central fatigue appeared somewhat higher in children than endurance athletes, both children and endurance athletes experienced greater decrements than adults. Therefore, children exhibit a more comparable neuromuscular fatigue profile to endurance athletes than adults.
Collapse
Affiliation(s)
| | - Enzo Piponnier
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| | - Emeric Chalchat
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Valérie Julian
- Clermont-Ferrand University Hospital, Clermont-Ferrand, France
| | - Olivia Bocock
- Clermont-Ferrand University Hospital, Clermont-Ferrand, France
| | - Martine Duclos
- Clermont-Ferrand University Hospital, Clermont-Ferrand, France
| | - Vincent Martin
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| | - Sébastien Ratel
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| |
Collapse
|
50
|
Maturity-Related Differences in Systemic Pulmonary and Localized Fatigue Threshold Among Youth Male Athletes. Pediatr Exerc Sci 2019; 31:99-106. [PMID: 30251936 DOI: 10.1123/pes.2017-0250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To examine the reliability and the maturity-related differences of fatigue thresholds (FTs) among youth males. METHODS Twenty-nine youth males (11-17 y) completed 2 ramp exercise tests on a cycle ergometer. Systemic FTs were calculated from gas exchange and ventilation variables. Localized FTs were calculated from electromyography and near-infrared spectroscopy of the vastus lateralis. All FTs were determined using the maximal distance method and expressed relative to maximal oxygen consumption. All participants were grouped according to the number of years from peak height velocity into PRE- (< -1.5 y), PERI- (-1.5 to +1.5 y) and POST- (> +1.5 y) peak height velocity. Reliability was assessed with intraclass correlation coefficients, and differences between groups were assessed with analysis of variance and Cohen's d coefficients. RESULTS Analysis of variance revealed significant group differences with PRE having significantly greater systemic pulmonary FTs than POST, while localized muscular FTs were significantly greater in PRE when compared with PERI and POST. All FTs exhibited excellent reliability (intraclass correlation coefficient > .75) in all maturity groups. CONCLUSION Maturity status appears to influence the onset of FTs among youth male athletes, with FTs occurring later in younger athletes. Furthermore, all FTs were reliable measures regardless of maturity.
Collapse
|