Chronic capsiate supplementation increases fat-free mass and upper body strength but not the inflammatory response to resistance exercise in young untrained men: a randomized, placebo-controlled and double-blind study

BACKGROUND

Acute capsaicinoid and capsinoid supplementation has endurance and resistance exercise benefits; however, if these short-term performance benefits translate into chronic benefits when combined with resistance training is currently unknown. This study investigated changes of chronic Capsiate supplementation on muscular adaptations, inflammatory response and performance in untrained men.

METHODS

Twenty untrained men were randomized to ingest 12 mg Capsiate (CAP) or placebo in a parallel, double-blind design. Body composition and performance were measured at pre-training and after 6 weeks of resistance training. An acute resistance exercise session test was performed pre and post-intervention. Blood samples were collected at rest and post-resistance exercise to analyze Tumor necrosis factor- (TNF-), Soluble TNF- receptor (sTNF-r), Interleukin-6 (IL-6) and Interleukin-10 (IL-10).

RESULTS

Exercise and CAP supplementation increased fat-free mass in comparison to baseline by 1.5 kg (P < 0.001), however, the majority of the increase (1.0 kg) resulted from an increase in total body water. The CAP change scores for fat-free mass were significantly greater in comparison to the placebo (CAP ∆%= 2.1 ± 1.8 %, PLA ∆%= 0.7 ± 1.3 %, P = 0.043) and there was a significant difference between groups in the bench press exercise (P = 0.034) with greater upper body strength change score for CAP (∆%= 13.4 ± 9.1 %) compared to placebo (∆%= 5.8 ± 5.2 %), P = 0.041. CAP had no effect on lower body strength and no supplementation interactions were observed for all cytokines in response to acute resistance exercise (P > 0.05).

CONCLUSION

Chronic Capsiate supplementation combined with resistance training during short period (6 weeks) increased fat-free mass and upper body strength but not inflammatory response and performance in young untrained men.

Potential Mechanisms Behind the Blood Pressure-Lowering Effect of Dynamic Resistance Training

PURPOSE OF REVIEW

To elucidate the hemodynamic, autonomic, vascular, hormonal, and local mechanisms involved in the blood pressure (BP)-lowering effect of dynamic resistance training (DRT) in prehypertensive and hypertensive populations.

RECENT FINDINGS

The systematic search identified 16 studies involving 17 experimental groups that assessed the DRT effects on BP mechanisms in prehypertensive and/or hypertensive populations. These studies mainly enrolled women and middle-aged/older individuals. Vascular effects of DRT were consistently reported, with vascular conductance, flow-mediated dilation, and vasodilatory capacity increases found in all studies. On the other hand, evidence regarding the effects of DRT on systemic hemodynamics, autonomic regulation, hormones, and vasoactive substances are still scarce and controversial, not allowing for any conclusion. The current literature synthesis shows that DRT may promote vascular adaptations, improving vascular conductance and endothelial function, which may have a role in the BP-lowering effect of this type of training in prehypertensive and hypertensive individuals. More studies are needed to explore the role of other mechanisms in the BP-lowering effect of DRT.

10-Weeks of resistance training improves sleep quality and cardiac autonomic control in persons with multiple sclerosis

PURPOSE

To examine the acute and chronic effects of 10-weeks of progressive resistance training on sleep quality and sleeping heart rate variability in persons with Multiple Sclerosis (pwMS).

METHODS

Eighteen pwMS (age = 44.8 ± 10.6 years; EDSS = 3.1 ± 1.7) completed a 10-week of resistance training, with three training sessions per week. Each session consisted of 4 lower body exercises, performing 2-4 sets of each exercise, with 8-15 repetitions each set, at an intensity ranging from 60 to 75% of 1-repetition maximum. Subjective and actigraphic sleep quality and sleeping heart rate variability were carried out at 4 different times: (1) Before the starting of the intervention on a rest day; (2) the night after training week 1 (3) the night after training week 10 and 4) after completing the resistance training program on a rest day.

RESULTS

Regarding subjective sleep quality, significant main effects were observed on the variables of sleep quality, sleep comfort, easy of falling sleep, easy of waking up and felling of rest. Sleep quality, sleep comfort and easy of falling sleep were greater in rest night in week 1 vs. rest night in week 10_. Actigraphic sleep quality also improved after the training program (rest night in week 1 vs. rest night in week 10). In the pair-wise comparison showed an acute effect in the session after the training program (rest night in week 10< training night in week 10) on HF, pNN50 and RMMSD.

CONCLUSIONS

Resistance training is a non-pharmacological treatment that has the capacity to improve the regulation of autonomic system and, consequently, the sleep quality in pwMS.Implications for rehabilitation10 Weeks of resistance training improves the sleep quality of persons with multiple sclerosis.Resistance training can modulate autonomic cardiac control in this population.Improving the sleep quality is essential for persons with MS because of its close relationship to other variables, such as symptomatic fatigue.

Vitamin D3 supplementation does not enhance the effects of resistance training in older adults

BACKGROUND

Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored.

METHODS

Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables  = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments.

RESULTS

Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study.

CONCLUSIONS

Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD.

Feasibility and preliminary effect of anabolic steroids in addition to strength training and nutritional supplement in rehabilitation of patients with hip fracture: a randomized controlled pilot trial (HIP-SAP1 trial)

Background

Anabolic steroid has been suggested as a supplement during hip fracture rehabilitation and a Cochrane Review recommended further trials. The aim was to determine feasibility and preliminary effect of a 12-week intervention consisting of anabolic steroid in addition to physiotherapy and nutritional supplement on knee-extension strength and function after hip fracture surgery.

Methods

Patients were randomized (1:1) during acute care to: 1. Anabolic steroid (Nandrolone Decanoate) or 2. Placebo (Saline). Both groups received identical physiotherapy (with strength training) and a nutritional supplement. Primary outcome was change in maximal isometric knee-extension strength from the week after surgery to 14weeks. Secondary outcomes were physical performance, patient reported outcomes and body composition.

Results

Seven hundred seventeen patients were screened, and 23 randomised (mean age 73.4years, 78% women). Target sample size was 48. Main limitations for inclusion were not home-dwelling (18%) and cognitive dysfunction (16%). Among eligible patients, the main reason for declining participation was Overwhelmed and stressed by situation (37%). Adherence to interventions was: Anabolic steroid 87%, exercise 91% and nutrition 61%. Addition of anabolic steroid showed a non-significant between-group difference in knee-extension strength in the fractured leg of 0.11 (95%CI -0.25;0.48) Nm/kg in favor of the anabolic group. Correspondingly, a non-significant between-group difference of 0.16 (95%CI -0.05;0.36) Nm/Kg was seen for the non-fractured leg. No significant between-group differences were identified for the secondary outcomes. Eighteen adverse reactions were identified (anabolic=10, control=8).

Conclusions

Early inclusion after hip fracture surgery to this trial seemed non-feasible, primarily due to slow recruitment. Although inconclusive, positive tendencies were seen for the addition of anabolic steroid.

Trial registration

Clinicaltrials.gov NCT03545347.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02273-z.

Effects of different resistance training frequencies on body composition and muscular performance adaptations in men

BACKGROUND

The aim of this study was to compare the effects of 8 weeks resistance training (RT) with two sessions versus four sessions per week under volume load-equated conditions on body composition, maximal strength, and explosive actions performance in recreationally trained men.

METHODS

Thirty-five healthy young men participated in the study and were randomly divided into a two sessions per-week RT (RT2, n = 12), four sessions per-week RT (RT4, n = 13) or a control group (CG, n = 10). All subjects were evaluated for thigh, chest and arm circumference, countermovement jump (CMJ), medicine ball throw (MBT), 1-repetition maximum (1RM) leg press, bench press, arm curl, muscular endurance (i.e., 60% of 1RM to failure) for leg press, and bench press at pre, mid (week 4) and post an 8-week training intervention.

RESULTS

A two-way analysis of variance with repeated measures (3 [group] × 3 [time]) revealed that both training groups increased chest and thigh circumferences, strength and explosive actions performance tests in comparison to CG following 8 weeks of training (p = 0.01 to 0.04). Group × time interactions were also noted in 1RM bench press (effects size [ES] = 1.07 vs. 0.89) and arm curl (ES = 1.15 vs. 0.89), with greater gains for RT4 than RT2 (p = 0.03).

CONCLUSION

RT improved muscle strength, explosive actions performance and markers of muscle size in recreationally trained men; however, four sessions of resistance training per week produced greater gains in muscular strength for the upper body measures (i.e., 1RM bench press and arm curl) when compared to two sessions per week under volume-equated conditions.

Effects of proprioceptive exercises and strengthening on pain and functionality for patellofemoral pain syndrome in women: A randomized controlled trial

OBJECTIVE

The objective of this study was to verify the effects of resisted and proprioceptive exercises program for the treatment of patients diagnosed with patellofemoral pain syndrome (PFPS).

DESIGN METHOD

Randomized Controlled Trial - level of evidence, II.

METHODS

Sixty female patients, clinically diagnosed with PFPS, were allocated into two experimental groups. The exercise group (ExG) underwent 6 weeks of a resisted and proprioceptive exercises for the trunk muscles, abductors and lateral hip rotators and knee extensors. The Guidance Group (GG) received educational, cognitive and behavioral guidance on healthcare. Before and after the program implementation period, all participants were evaluated in relation to the injured limb for pain assessment, subjective functionality, maximum isometric strength and 2D biomechanical analysis.

RESULTS

After a six-week follow-up, ExG showed significant improvement in the Numerical Pain Rating Scale, Anterior Knee Pain Scale and Knee Outcome Survey- Activities of Daily Living Scale when compared to the control group (p ≤ 0,05). The ExG also proved superior for increased muscle strength of knee extensors, hip abductors, decreased dynamic knee valgus and pelvic drop in relation to GG (p ≤ 0.05). However, when we consider the strength of the hip lateral rotator muscles there was no difference between the two interventions (p > 0.05).

CONCLUSION

Resisted and proprioceptive exercises yielded superior results to those of a treatment focused on educational, cognitive and behavioral guidance in improving pain and lower limb function for women with PFPS.

[Acute rupture of the pectoralis major muscle at the musculotendinous junction : Case report of a rare injury and literature review]

Die Pectoralis-major-Ruptur (PMR) ist eine seltene Verletzung, die v. a. beim Kraftsport aufritt. Vorgestellt wird der Fall eines 31-jährigen Profibasketballspielers, der sich beim Bankdrücken eine Komplettruptur am muskulotendinösen Übergang des M. pectoralis major (PM) zugezogen hatte. Drei Wochen nach dem erlittenen Trauma erfolgte bei persistierenden Schmerzen und Kraftdefizit die Refixation des PM. Drei Monate postoperativ konnte der Patient bei vollem Bewegungsumfang schmerzfrei in den Basketballsport zurückkehren. Die Verletzungsentität wird vor dem Hintergrund der aktuellen Literatur diskutiert und das operative Vorgehen im Detail dargestellt.

Real-time mechanical responses to overload and fatigue using a flywheel training device

PURPOSE

This study aimed to analyze mechanical performance and mechanical losses across different sets and repetitions of unilateral leg extensions under flywheel loading conditions.

METHODS

In a cross-over design, 23 physically active participants executed 3 sets of 30 repetitions using two different loads. Angular speed, angular acceleration and power were monitored, and mean and peak values of these variables were calculated for each set of repetitions. We analyzed time-course differences every five repetitions (described as 'clusters'). Differences in the mechanical profile for Load by Set and in the mechanical losses for Load by Set by Cluster repetitions were analyzed using an ANOVA repeated measures test. A Principal Components (PC) analysis was also conducted.

RESULTS

Only peak acceleration showed a significant Set by Load interaction (p = 0.006) in mechanical performance. At the intra-set level, all consecutive clusters showed a significant decrement in all variables, but with different magnitudes (speed < acceleration < power). Although all variables showed significant Set by Cluster and Load by Cluster interactions, only the acceleration variables showed a significant Set by Load interaction (p < 0.05). All the variables showed a single PC. Higher fatigue was found around the concentric peak for each variable.

CONCLUSIONS

The most sensitive variable for detecting fatigue using real-time feedback seems to be the angular acceleration of the flywheel. Peak acceleration can be used to monitor training workload and training volume in real time in leg extension exercises using flywheel training devices.

Responsiveness to muscle mass gain following 12 and 24 weeks of resistance training in older women

BACKGROUND

Many factors may influence the magnitude of individual responses to resistance training (RT). How the manipulation of training volume and frequency affects responsiveness level for muscle mass gain in older women has not been investigated.

AIMS

This study had the objective of identifying responders (RP) and non-responders (N-RP) older women for skeletal muscle mass (SMM) gain from a 12-week resistance training (RT) program. Additionally, we analyzed whether the N-RP could gain SMM with an increase in weekly training volume over 12 additional weeks of training.

METHODS

Thirty-nine older women (aged ≥ 60 years) completed 24 weeks of a whole-body RT intervention (eight exercises, 2-3×/week, 1-2 sets of 10-15 repetitions). SMM was estimated by DXA, and the responsive cut-off value was set at two times the standard error of measurement. Participants were considered as RP if they exceeded the cut-off value after a 12-week RT phase, while the N-RP were those who failed to reach the SMM cut-off.

RESULTS

Of the 22 participants considered to be N-RP, only 3 accumulated SMM gains (P = 0.250) that exceeded the cut-off point for responsiveness following 12 additional weeks of training, while 19 maintained or presented negative SMM changes. Of the 17 participants considered to be RP, all continued to gain SMM after the second 12-week RT phase. No significant correlation was observed between the changes in SMM and any baseline aspect of the participants.

CONCLUSIONS

Our results suggest that some older women are RP, while others are N-RP to SMM gains resulting from RT. Furthermore, the non-responsiveness condition was not altered by an increase of training volume and intervention duration while RP participants continue to increase SMM; it appears that RP continue to be RP, and N-RP continue to be N-RP.

Does resistance training promote enough muscular strength increases to move weak older women to better strength categories?

We compared the magnitude of muscular strength changes among older women occupants of different strength tertiles in response to progressive resistance-training (RT). Additionally, we examined the possibility of older women initially characterized as weak (occupants of the lower tertile of strength status) can achieve a higher muscular strength level to be inserted into a better category (middle or upper tertiles). The present investigation was attended by 113 physically independent older women (>60 years old). Muscular strength was assessed by one-repetition maximum (1RM) tests on chest press, preacher curl, leg extension exercises, and by the isokinetic (ISOK) peak torque of knee extension and flexion at 60 and 180°/s angular velocities. The RT lasted 12 weeks (3 x/week) and consisted of eight exercises for the whole body. The participants were divided into tertiles (LOWER, MIDDLE, and UPPER) according to the performance at baseline for each strength measure. After RT, the LOWER tertile showed more significant magnitude gains than the UPPER tertile to the 1RM in leg extension and preacher curl and isokinetic measurements (6.9-36.3%). A considerable number of older women increased muscular strength enough to move from LOWER to MIDDLE or UPPER tertiles. From our results, it can be inferred that older women occupants of the lower strength tertile show more significant muscular strength gains when compared to their stronger counterparts. Moreover, 12 weeks of RT seem to be sufficient to transfer older women previously characterized as "weak" to a better category.

[Reference values in isometric strength diagnostics : Measurement of core strength values in patients with back pain]

OBJECTIVE

Isometric strength testing is known as a valid and reliable tool in the context of functional diagnostics and quality control for chronic low back pain rehabilitation, but reference values differ markedly between varied assessment devices, depending on their biomechanical lever arm framework. This study aimed to evaluate sex and age-specific isometric peak force reference values of trunk muscle functions in all dimensions using the Myoline® test device (Diers, Schlangenbad, Germany).

MATERIAL AND METHODS

In a retrospective cross-sectional study, data of 678 (541 females, 137 males) age-clustered (18-35, 36-50, 51-65 years) low back pain patients (ICD-10: M54) were analyzed referring to their absolute (N) and body weight related (N/kg) isometric maximum peak forces in all spatial dimensions (flexion, extension, rotation, lateral flexion) and the corresponding ratios (M ± SD, 95% CI), accompanied by sex and age-related effect analyses (two-way ANOVA).

RESULTS

Male and younger patients were significantly stronger than females and older patients (p < 0.05), but none of the ratios differed significantly between any sex or age cluster (p > 0.05). The flexion/extension ratio showed a 1:2 relation, and the rotation and lateral flexion ratios demonstrated a 1:1 relation, but all ratios varied markedly (30-50%).

CONCLUSIONS

The demonstrated data represented a special norm for sex and age clustered low back pain patients assessed with the recent Myoline® test device. The markedly varying peak forces and their ratios underlined the individual diversity and heterogeneous state of functional capacities within low back pain patients.

Does regular strength training cause urinary incontinence in overweight inactive women? A randomized controlled trial

Introduction and hypothesis

Urinary incontinence (UI) is common in women who exercise. We aimed to investigate new onset UI in formerly inactive, overweight or obese women (BMI > 25) participating in three different strength training modalities compared with a non-exercising control group.

Methods

This was a secondary analysis of an assessor blinded randomized controlled trial investigating the effect of 12 weeks of three strength training concepts for women on muscle strength and body composition. None of the programs included pelvic floor muscle training. International Consensus on Incontinence Questionnaire Urinary Incontinence Short Form (ICIQ-UI-SF) was used to investigate primary outcome; new onset UI, and secondary outcome; ICIQ-UI-SF sum score. Suissa and Shuster’s exact unconditional test was used to analyze difference in new onset UI. Difference in ICIQ-UI-SF sum score is presented as mean with 95% CI.

Results

At baseline 40 out of 128 (31.2%) participants reported UI. Three out of 27, 2 out of 17, 2 out of 23, and 0 out of 21 women in the three training and control groups respectively had new onset UI. There were no statistically significant differences in new onset UI across the groups or when collapsing new onset UI in the intervention groups compared with the controls (7 out of 67 vs 0 out of 21), p = 0.124. After the intervention the control group reported worse ICIQ-UI-SF sum score than any of the training groups; mean difference − 6.6 (95% CI: −11.9, −1.27), p = 0.012, but there was no difference in change from baseline to 12 weeks between the groups p = 0.145).

Conclusions

There was no statistically significant change in UI after strength training.

Ten-year resistance training background modulates somatosensory P3 cognitive brain resonse in older men: A magnetoencephalograpy study

The brain electrophysiological component P3, associated with good cognitive abilities, deteriorates during healthy aging. Both cognitive functions and P3 component amplitude respond positively to exercise, but the effects of resistance training on P3 are much less studied. Short-term resistance training interventions in older adults indicate modulation towards larger P3 amplitude, but this association has not been studied with a longitudinal study design. We investigated magnetoencephalographically recorded P3 (P3m) in a unique study design of nine aged men (mean age 77.7 y) with quasi-supervised resistance training background over a 10-year period and eight controls of similar age (mean age 77.5 y) with no training background. We elicited P3m utilizing lower limb electrical stimulation, as the resistance training program was mostly directed to lower limbs. Somatosensory oddball paradigm was performed with the right foot's fourth toe as standard (90%) and hallux as deviant (10%). Participants were asked to respond to deviants with a button press using their left index finger. Topographic maps showed bilateral temporoparietal activation for P3m in both groups. No amplitude differences were found in active P3m regions between groups. However, the groups differed in hemispheric activity of P3m. The exercise group showed stronger activation in the right frontotemporal and parietal sensor-groups compared to the left sensor-groups, and the control group showed stronger activation in right frontotemporal sensor-group compared to left. The control group showed shorter P3m latency in the right temporal sensor-group than the exercise group, but the latencies in other sensor-groups were similar. In aging, the brain utilizes compensatory areas to perform cognitive tasks. Our results suggest modulation in topographic distribution of P3m activity in aging men with long-term resistance training background compared to their controls. This might arise from a difference in age-related compensatory mechanisms in P3m generation.

Muscular HSP70 content is higher in elderly compared to young, but is normalized after 12 weeks of strength training

Purpose

Aging is associated with increased myocellular stress and loss of muscle mass and function. Heat shock proteins (HSPs) are upregulated during periods of stress as part of the cells protective system. Exercise can affect both acute HSP regulation and when repeated regularly counteract unhealthy age-related changes in the muscle. Few studies have investigated effects of exercise on HSP content in elderly. The aim of the study was to compare muscular HSP levels in young and elderly and to investigate how training affects HSP content in muscles from aged males and females.

Methods

Thirty-eight elderly were randomized to 12 weeks of strength training (STG), functional strength training (FTG) or a control group (C). To compare elderly to young, 13 untrained young performed 11 weeks of strength training (Y). Muscle biopsies were collected before and after the intervention and analyzed for HSP27, αB-crystallin and HSP70.

Results

Baseline HSP70 were 35% higher in elderly than in young, whereas there were no differences between young and elderly in HSP27 or αB-crystallin. After the training intervention, HSP70 were reduced in STG (− 33 ± 32%; P = 0.001) and FTG (− 28 ± 30%; P = 0.012). The decrease in HSP70 was more pronounced in the oldest. In contrast, Y increased HSP27 (134 ± 1%; P < 0.001) and αB-crystallin (84 ± 94%; P = 0.008).

Conclusion

Twelve weeks of STG or FTG decreased the initial high levels of HSP70 in aged muscles. Thus, regular strength training can normalize some of the increases in cellular stress associated with normal aging, and lead to a healthier cellular environment in aged muscle cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00421-021-04633-4.

Is there an athlete's artery? A comparison of brachial and femoral artery structure and function in male strength, power and endurance athletes

OBJECTIVES

Exercise places physiological demands upon the cardiovascular system, subsequently leading to adaptations in structure and function. Different exercise modalities (endurance, strength and power) lead to distinct hemodynamic demands and, possibly, different patterns of adaptation. Our aim was to assess and compare brachial and femoral artery function and structure in elite level athletes engaged in endurance, strength and power sports.

DESIGN

cross sectional comparison.

METHODS

30 male elite athletes (runners n=10, powerlifters n=11, weightlifters n=9) and 23 healthy controls were recruited. Brachial and femoral arterial diameters were assessed using ultrasound. Arterial function (brachial and femoral arteries) was determined using the flow mediated dilation (FMD) technique and body composition using body mass index (BMI) and body surface area (BSA).

RESULTS

Weightlifters had significantly larger brachial arterial diameters compared to controls (4.39±0.34 vs 3.86±0.42mm, p<0.01). As weightlifter and power athletes had significantly higher body mass, BMI and BSA, we adjusted diameter for BSA. BSA-correction ameliorated differences in brachial artery resting diameters between athletes and controls. However, BSA-corrected femoral artery diameter was significantly larger in runners compared to controls (3.51±0.28 vs 3.25±0.34mm, p<0.05). There were no differences in brachial FMD between groups. Femoral artery FMD was significantly higher in runners and weightlifters compared to controls (p<0.05 for both groups).

CONCLUSIONS

Heterogeneous, limb-specific structural and functional vascular adaptation is evident in athletes, which may be influenced by exercise modality. Further, vascular remodelling relates to differences in body shape, specifically body composition, which should be accounted for when comparing athletes.

The effects of 12 weeks of functional strength training on muscle strength, volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel

BACKGROUND

Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel, including inducing neck and back pain. The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1) the volume and strength of the neck and shoulder muscles and 2) muscular activity upon exposure to helmets of different masses and elevated G_z forces in a long-arm centrifuge in high-performance aircraft personnel.

METHODS

Eighteen participants underwent 12 weeks of functional strength training (n = 12) or the control protocol (n = 6) without additional strength training. Pre- and post-intervention tests included evaluations of isometric strength of the head extensor muscles, flexion, and lateral flexion and rotation, as well as magnetic resonance imaging (MRI) to measure the volume of the m. sternocleidomastoideus, m. trapezius, and deep neck muscles. Furthermore, during a long-arm centrifuge (+ 1.4 and + 3 G_z) protocol, the muscular activity levels of the m. sternocleidomastoideus, m. trapezius and m. erector spinae muscles were assessed without a flight helmet, with a helmet, and with a helmet and night vision goggles. Each participant's perception of muscular strain was noted immediately after the long-arm centrifuge protocol.

RESULTS

The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group (P < 0.05). Relative muscle activity (%MVC) with a helmet decreased after the intervention in the training but not the control group (P = 0.01). Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group (P < 0.01). The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.

CONCLUSION

Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated G_z forces in a long-arm centrifuge.

Skeletal Muscle Mitochondrial Adaptations to Maximal Strength Training in Older Adults

Maximal strength training (MST) results in robust improvements in skeletal muscle force production, efficiency, and mass. However, the effects of MST on muscle mitochondria are still unknown. Accordingly, the purpose of this study was to examine, from the molecular level to whole-muscle, mitochondrial adaptations induced by 8 weeks of knee-extension MST in the quadriceps of 10 older adults using immunoblotting, spectrophotometry, high-resolution respirometry in permeabilized muscle fibers, in vivo 31P magnetic resonance spectroscopy (31P-MRS), and gas exchange. As anticipated, MST resulted in an increased isometric knee-extensor force from 133 ± 36 to 147 ± 49 Nm (p < .05) and quadriceps muscle volume from 1,410 ± 103 to 1,555 ± 455 cm3 (p < .05). Mitochondrial complex (I-V) protein abundance and citrate synthase activity were not significantly altered by MST. Assessed ex vivo, maximal ADP-stimulated respiration (state 3CI+CII, PRE: 23 ± 6 and POST: 14 ± 5 ρM·mg-1·s-1, p < .05), was decreased by MST, predominantly, as a result of a decline in complex I-linked respiration (p < .05). Additionally, state 3 free-fatty acid linked respiration was decreased following MST (PRE: 19 ± 5 and POST: 14 ± 3 ρM·mg-1·s-1, p < .05). Assessed in vivo, MST slowed the PCr recovery time constant (PRE: 49 ± 13 and POST: 57 ± 16 seconds, p < .05) and lowered, by ~20% (p = .055), the quadriceps peak rate of oxidative ATP synthesis, but did not significantly alter the oxidation of lipid. Although these, likely qualitative, mitochondrial adaptations are potentially negative in terms of skeletal muscle energetic capacity, they need to be considered in light of the many improvements in muscle function that MST affords older adults.

Resistance exercise training among young adults with analogue generalized anxiety disorder

INTRODUCTION

The objective of this randomized controlled trial (RCT) was to quantify the effects of eight weeks of World Health Organization and American College of Sports Medicine guidelines-based resistance exercise training (RET) among participants meeting criteria for subclinical, or analogue-GAD (AGAD) METHODS: Forty-four participants (mean age (y): 25.4.6±4.9.2) were randomized to either an eight-week, fully-supervised, one-on-one RET intervention or wait-list control. AGAD status was determined using validated cut-scores for both the Psychiatric Diagnostic Screening Questionnaire-GAD subscale (≥6) and Penn State Worry Questionnaire (≥45). Remission, based on change in AGAD status, was assessed post-intervention, and quantified with number needed to treat (NNT). Primary analyses focused on participants missing outcome data at ≤1 time point (RET: n=12, Wait-list: n=15). RM-ANCOVA examined differences between RET and wait-list across time. Simple effects analysis decomposed significant interactions. Hedges' d quantified magnitude of differences in change between conditions over time.

RESULTS

Attendance was 81% and compliance to the RET was 77%. Participants significantly increased strength (all d≥1.24, p≤0.006) with no adverse events. RET improved AGAD status (NNT=3, 95%CI: 2 to 7). Significant group X time interactions were found for worry (F_(3,66) = 3.12, p≤0.043; d=0.93, 95%CI: 0.13 to 1.73) and anxiety symptoms (F_(3,57.84)=2.91, ε=0.88, p≤0.045; d=0.71, 95%CI: -0.08 to 1.49). RET significantly reduced worry (mean difference=-6.49, p≤0.045) and anxiety symptoms (mean difference=-10.50, p≤0.001).

LIMITATIONS

Limitations include a small sample size, and lack of attention-matched control condition.

CONCLUSION

RET significantly improved AGAD severity, and elicited large, clinically meaningful improvements in worry and anxiety symptoms among young adults with AGAD.

Changes in sprint performance and sagittal plane kinematics after heavy resisted sprint training in professional soccer players

Background

Sprint performance is an essential skill to target within soccer, which can be likely achieved with a variety of methods, including different on-field training options. One such method could be heavy resisted sprint training. However, the effects of such overload on sprint performance and the related kinetic changes are unknown in a professional setting. Another unknown factor is whether violating kinematic specificity via heavy resistance will lead to changes in unloaded sprinting kinematics. We investigated whether heavy resisted sled training (HS) affects sprint performance, kinetics, sagittal plane kinematics, and spatiotemporal parameters in professional male soccer players.

Methods

After familiarization, a nine-week training protocol and a two-week taper was completed with sprint performance and force-velocity (FV) profiles compared before and after. Out of the two recruited homogenous soccer teams (N = 32, age: 24.1 ± 5.1 years: height: 180 ± 10 cm; body-mass: 76.7 ± 7.7 kg, 30-m split-time: 4.63 ± 0.13 s), one was used as a control group continuing training as normal with no systematic acceleration training (CON, N = 13), while the intervention team was matched into two HS subgroups based on their sprint performance. Subgroup one trained with a resistance that induced a 60% velocity decrement from maximal velocity (N = 10, HS60%) and subgroup two used a 50% velocity decrement resistance (N = 9, HS50%) based on individual load-velocity profiles.

Results

Both heavy resistance subgroups improved significantly all 10–30-m split times (p < 0.05, d =  − 1.25; −0.62). Post-hoc analysis showed that HS50% improved significantly more compared to CON in 0–10-m split-time (d = 1.03) and peak power (d = 1.16). Initial maximal theoretical horizontal force capacity (F0) and sprint FV-sprint profile properties showed a significant moderate relationship with F0 adaptation potential (p < 0.05). No significant differences in sprinting kinematics or spatiotemporal variables were observed that remained under the between-session minimal detectable change.

Conclusion

With appropriate coaching, heavy resisted sprint training could be one pragmatic option to assist improvements in sprint performance without adverse changes in sprinting kinematics in professional soccer players. Assessing each player’s initial individual sprint FV-profile may assist in predicting adaptation potential. More studies are needed that compare heavy resisted sprinting in randomized conditions.

Functional relevance of resistance training-induced neuroplasticity in health and disease

Repetitive, monotonic, and effortful voluntary muscle contractions performed for just a few weeks, i.e., resistance training, can substantially increase maximal voluntary force in the practiced task and can also increase gross motor performance. The increase in motor performance is often accompanied by neuroplastic adaptations in the central nervous system. While historical data assigned functional relevance to such adaptations induced by resistance training, this claim has not yet been systematically and critically examined in the context of motor performance across the lifespan in health and disease. A review of muscle activation, brain and peripheral nerve stimulation, and imaging data revealed that increases in motor performance and neuroplasticity tend to be uncoupled, making a mechanistic link between neuroplasticity and motor performance inconclusive. We recommend new approaches, including causal mediation analytical and hypothesis-driven models to substantiate the functional relevance of resistance training-induced neuroplasticity in the improvements of gross motor function across the lifespan in health and disease.

Interaction effects of different orders of resistance exercises and rest intervals on performances by young athletes

OBJECTIVE

The purpose of this study was to verify the acute effects of different exercise orders and rest intervals between sets on young athletes performance.

METHOD

Sixteen young male football players (73.2 ± 4.8 kg, 177.5 ± 5.1 cm, BMI 23.2 ± 1.1, 19.8 ± 0.9 years) completed six experimental strength training (ST) sessions with different exercise order sequences (A and B) and rest interval lengths (1 min, 3 min, and self-selected).In Sequence A the exercises were: bench press (BP), back squat (BS), biceps curl (BC) and plantar flexion (PF); while Sequence B was performed in the opposite order (i.e. PF, BC, BS and BP).The total work volume (TWV) per exercise (sets x repetitions x load) and per training session (sum of the TWV of all exercises) were evaluated for all ST sessions.

RESULTS

BC and PF exercises presented higher TWV in sequence B (p ≤ 0.05). Already, the exercises BP, BS and PF presented higher TWV with 3 min and self-selected rest intervals (p ≤ 0.05). The 3-min and self-selected rest intervals presented higher values of TWV per training session compared to the 1-min rest interval (p ≤ 0.05).

CONCLUSION

The exercise order influenced certain exercises (BC and PF), which presented higher TWV when positioned at the beginning of a sequence. While the longer rest intervals (3 min and self-selected) resulted in higher TWV per exercise (BP, BS and PF) and per training session. These results suggest that self-selected rest interval can be implemented to increase training efficiency in young athletes.

A Comparison of Muscle Activation between Barbell Bench Press and Dumbbell Flyes in Resistance-Trained Males

The purpose of the study was to compare the muscle activity in the prime movers and antagonist between the barbell bench press (BBP) and the dumbbell flyes (DF) Seventeen resistance-trained men (age 22.9 ± 1.8 yrs; height 1.80 ± 0.06 m; body mass 80.0 ± 8.3 kg), with 4.8 ± 2.0 years resistance training experience, completed the study. The surface electromyographic activation was measured in four different muscles (pectoralis major, anterior deltoids, triceps brachii, and biceps brachii) during six repetition maximum loads in both exercises. To better understand eventual differences, an in-depth analysis of the fifth repetition was performed, dividing it into six phases (lower, middle, and upper phase of the descending and ascending movement). The results showed a higher muscle activation in the whole movement and the majority of the lifting phases for pectoralis major, deltoids anterior, and triceps brachii for the BBP compared to the DF (8-81 %, p ≤ 0.05). However, the antagonist biceps brachii showed a higher muscle activation (57-86 %, p ≤ 0.05) in the DF compared to the BBP. In conclusion, both exercises could be included in training programs, but the BBP should be emphasized because of the higher muscle activation overall. Among specific populations, were tasks based on strength and control in a horizontal shoulder flexion position with extended elbows often occurs, the DF might prove useful.

Cardiovascular Acute Effects of Traditional vs. Paired Set Resistance Training in Patients With Liver Cirrhosis

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

A Systematic Review of Workplace Interventions to Rehabilitate Musculoskeletal Disorders Among Employees with Physical Demanding Work

Purpose This systematic review investigates the effectiveness of workplace interventions to rehabilitate musculoskeletal disorders (MSDs) among employees with physically demanding work. Methods A systematic search was conducted in bibliographic databases including PubMed and Web of Science Core Collection for English articles published from 1998 to 2018. The PICO strategy guided the assessment of study relevance and the bibliographical search for randomized controlled trials (RCTs) and non-RCTs in which (1) participants were adult workers with physically demanding work and MSD (including specific and non-specific MSD and musculoskeletal pain, symptoms, and discomfort), (2) interventions were initiated and/or carried out at the workplace, (3) a comparison group was included, and (4) a measure of MSD was reported (including musculoskeletal pain, symptoms, prevalence or discomfort). The quality assessment and evidence synthesis adhered to the guidelines developed by the Institute for Work & Health (Toronto, Canada) focusing on developing practical recommendations for stakeholders. Relevant stakeholders were engaged in the review process. Results Level of evidence from 54 high and medium quality studies showed moderate evidence of a positive effect of physical exercise. Within this domain, there was strong evidence of a positive effect of workplace strength training. There was limited evidence for ergonomics and strong evidence for no benefit of participatory ergonomics, multifaceted interventions, and stress management. No intervention domains were associated with "negative effects". Conclusions The evidence synthesis recommends that implementing strength training at the workplace can reduce MSD among workers with physically demanding work. In regard to workplace ergonomics, there was not enough evidence from the scientific literature to guide current practices. Based on the scientific literature, participatory ergonomics and multifaceted workplace interventions seem to have no beneficial effect on reducing MSD among this group of workers. As these interventional domains were very heterogeneous, it should also be recognized that general conclusions about their effectiveness should be done with care.Systematic review registration PROSPERO CRD42018116752 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=116752 ).