Assessment of Intercostal Muscle Near-Infrared Spectroscopy for Estimating Respiratory Compensation Point in Trained Endurance Athletes

This study aimed to assess the reliability and validity of estimating the respiratory compensation point (RCP) in trained endurance athletes by analyzing intercostal muscles' NIRS-derived tissue oxygenation dynamics. Seventeen experienced trail runners underwent an incremental treadmill protocol on two separate occasions, with a 7-day gap between assessments. Gas exchange and muscle oxygenation data were collected, and the oxygen saturation breakpoint (SmO2BP) measured in the intercostal muscles was compared to the RCP, which was identified by the increase in the VE/V.CO2 slope and the point at which the PetCO2 started to decrease. No statistically significant differences were observed between the two methods for any of the variables analyzed. Bland-Altman analysis showed significant agreement between the NIRS and gas analyzer methods for speed (r = 0.96, p < 0.05), HR (r = 0.98, p < 0.05), V.O2 relative to body mass (r = 0.99, p < 0.05), and %SmO2 (r = 0.98, p < 0.05). The interclass correlation coefficient values showed moderate to good reliability (0.60 to 0.86), and test-retest analysis revealed mean differences within the confidence intervals for all variables. These findings suggest that the SmO2BP measured using a portable NIRS device in the intercostal muscles is a reliable and valid tool for estimating the RCP for experienced trail runners and might be useful for coaches and athletes to monitor endurance training.

Effects of fast-velocity concentric resistance training in people with multiple sclerosis: A randomized controlled trial

OBJECTIVES

To analyze the effects of a fast-velocity concentric resistance training (FVCRT) program on maximum strength of upper and lower limb, gait speed, walking endurance, fatigue, physical self-perception, and catastrophizing pain in people with multiple sclerosis (MS).

MATERIALS AND METHODS

Participants were randomized to either an experimental [EG] (n = 18) or a control [CG] (n = 12) group. The EG carried out 10-weeks of lower limb FVCRT. The CG did not perform any intervention. The maximum isometric voluntary contraction (MVIC) during knee extension, hand-grip strength, gait speed, walking endurance, fatigue, physical self-perception, and catastrophizing pain were measured.

RESULTS

Inter-group differences after intervention were found on the right and left sides in MVIC (p = .032; ES = -0.7 and p = .009; ES = -0.9), and hand grip strength (p = .003; ES = -1.0 and p = .029; ES = -0.7). After FVCRT, there was in increase in MVIC (p < .001; ES = -1.7 and p < .001; ES = -1.3) and hand grip strength (p < .001; ES = -1.3 and p < .001; ES = -1.3) on both right and left sides, respectively. In addition, gait speed (p = .023; ES = 1.3), walking endurance (p < .001; ES = -1.0), symptomatic fatigue (p = .004; ES = 0.6), and catastrophizing pain (p < .001; ES = 1.0) improved in EG.

CONCLUSION

Lower limb FVCRT improved the upper and lower limb strength, walking, symptomatic fatigue, and catastrophizing pain in MS participants.

The Impact of Resistance Training Program on Static Balance in Multiple Sclerosis Population: A Randomized Controlled Trial Study

Background: Multiple sclerosis (MS) is a neurological disease that affects balance. Among the non-pharmacological strategies to improve this variable, physical exercise is one of the most widely used. However, the benefits of some types of training, such as resistance training, on static balance in this population are still unclear. This study aims to analyze the effects of a resistance training (RT) intervention on balance in people with MS. Methods: Thirty people with MS were randomized to either an experimental (n = 18) or a control (n = 12) group. The RT group performed 10 weeks of lower limb resistance training with a concentric phase at maximum velocity. Static balance was measured before and after intervention. Results: No significant group × time interaction effects were found (ANOVA test) in any of the variables at the end of the intervention. No intragroup differences were found before or after the intervention in the balance variables. Conclusions: Resistance training with a concentric phase at maximum velocity showed no impact on balance in our sample. Future studies should examine programs of longer duration or combined with other types of training, such as balance training, with the aim of obtaining improvements in this variable in people with MS.

The Consumption of a Synbiotic Does Not Affect the Immune, Inflammatory, and Sympathovagal Parameters in Athletes and Sedentary Individuals: A Triple-Blinded, Randomized, Place-bo-Controlled Pilot Study

This investigation aimed to identify the effect of a synbiotic in athletes and sedentary people, and their potential varying responses regarding the immune system, autonomic regulation and body composition. Twenty-seven participants were involved in the protocol: 14 sedentary and 13 semi-professional soccer players. Both groups were randomly divided into an experimental and control group. A synbiotic (Gasteel Plus^®, Heel España S.A.U.) comprising a blend of probiotic strains, including Bifidobacterium lactis CBP-001010, Lactobacillus rhamnosus CNCM I-4036, and Bifidobacterium longum ES1, was administered to the experimental group, and a placebo was given to the control group for 30 days. Heart rate variability, body composition, and immune/inflammatory cytokines were determined. Statistically significant differences were observed between sedentary individuals and athletes in heart rate variability but not between the experimental and control groups. A difference between the athletic and sedentary group is observed with the influence of training on the effects of the synbiotic on the levels of fat mass and body-fold sum. No significant differences were shown in cytokines after the protocol study. No changes occur with the synbiotic treatment between the athlete and sedentary groups, while no negative effect was produced. Further research will be necessary to see chronic effects in the analyzed biomarkers.

Fast-velocity resistance training improves force development and mobility in Multiple Sclerosis

This study aimed to analyze the benefits of a lower-limb fast-velocity concentric resistance training on rate of force development, mobility, and quality of life in people with Multiple Sclerosis. A randomized controlled trial was conducted in 30 people with Multiple Sclerosis, who were randomly assigned to either an experimental (n=18) or a control (n=12) group. The experimental group carried out 10-weeks of fast-velocity concentric resistance training, while the control group did not perform any intervention. Early and late rate of force development during knee extension in both legs, sit-to-stand and Timed Up and Go tests and quality life questionnaire were evaluated before and after intervention. The training program evoked an increase in early rate of force development in experimental group (0-30; Rightleg: 63.9%, p<0.001;ES=-1.4; Leftleg: 52.7%, p<0.001;ES=-1.0) compared to control group (showed modest increases). Furthermore, experimental group improved mobility after training (Sit-to-stand: 22.2%, p<0.001;ES=1.0; Timed Up and Go Test: 10.1%, p<0.001;ES=1.1) and increased the perception of quality of life after training, while control showed no changes. The fast-velocity concentric resistance training has the potential to improve early rate of force development and mobility after 10-weeks of training. In addition, the increase in self-perceived quality of life following this training modality demonstrates promising results in the Multiple Sclerosis population.

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.

The impact of COVID-19 home confinement on neuromuscular performance, functional capacity, and psychological state in Spanish people with Multiple Sclerosis

Background

The COVID-19 pandemic caused a global confinement of more than 2 months in Spain. As a result, the general population has significantly decreased their physical activity levels. The consequences of this abrupt, sedentary lifestyle in Spanish people with Multiple Sclerosis (pwMS) were unknown. Our aim was to examine the impact of COVID-19 home confinement on neuromuscular performance, functional capacity, physical self-perception, and anxiety in pwMS.

Methods

Eighteen pwMS (8:10 men/women, age: 43.41±10.88 years, Expanded Disability Status Scale: 2.85±1.34) participated in the study. Rate of force development (RFD) and maximal voluntary isometric contraction during knee extension in both legs, Timed-Up and Go test (TUG), sit-to-stand test, 6 min walk test, 10 m walk test, Physical-Self Perception Questionnaire (PSPQ) and State-Train Anxiety Inventory (STAI) were performed just before and after home confinement.

Results

A non-significant moderate effect (p = 0.07; ES = -0.48) was observed in the time in the sit-to-stand test compared to pre-home confinement. There was a significant increase in the time in TUG (p = 0.02; ES = -0.67). The PSQP score decreased (p = 0.01; ES = 0.79) and STAI-state increased (p = 0.01; ES = -0.65) following home confinement.

Conclusion

Home confinement had an impact on functional capacity, physical self-perception and state anxiety. However, neuromuscular performance was not altered after home confinement.

Differential Health Effects on Inflammatory, Immunological and Stress Parameters in Professional Soccer Players and Sedentary Individuals after Consuming a Synbiotic. A Triple-Blinded, Randomized, Placebo-Controlled Pilot Study

The main objective of this research was to carry out an experimental study, triple-blind, on the possible immunophysiological effects of a nutritional supplement (synbiotic, Gasteel Plus®, Heel España S.A.U.), containing a mixture of probiotic strains, such as Bifidobacterium lactis CBP-001010, Lactobacillus rhamnosus CNCM I-4036, and Bifidobacterium longum ES1, as well as the prebiotic fructooligosaccharides, on both professional athletes and sedentary people. The effects on some inflammatory/immune (IL-1β, IL-10, and immunoglobulin A) and stress (epinephrine, norepinephrine, dopamine, serotonin, corticotropin-releasing hormone (CRH), Adrenocorticotropic hormone (ACTH), and cortisol) biomarkers were evaluated, determined by flow cytometer and ELISA. The effects on metabolic profile and physical activity, as well as on various parameters that could affect physical and mental health, were also evaluated via the use of accelerometry and validated questionnaires. The participants were professional soccer players in the Second Division B of the Spanish League and sedentary students of the same sex and age range. Both study groups were randomly divided into two groups: a control group-administered with placebo, and an experimental group-administered with the synbiotic. Each participant was evaluated at baseline, as well as after the intervention, which lasted one month. Only in the athlete group did the synbiotic intervention clearly improve objective physical activity and sleep quality, as well as perceived general health, stress, and anxiety levels. Furthermore, the synbiotic induced an immunophysiological bioregulatory effect, depending on the basal situation of each experimental group, particularly in the systemic levels of IL-1β (increased significantly only in the sedentary group), CRH (decreased significantly only in the sedentary group), and dopamine (increased significantly only in the athlete group). There were no significant differences between groups in the levels of immunoglobulin A or in the metabolic profile as a result of the intervention. It is concluded that synbiotic nutritional supplements can improve anxiety, stress, and sleep quality, particularly in sportspeople, which appears to be linked to an improved immuno-neuroendocrine response in which IL-1β, CRH, and dopamine are clearly involved.

Effects of medium- and long-distance running on cardiac damage markers in amateur runners: a systematic review, meta-analysis, and metaregression

BACKGROUND

To finish an endurance race, athletes perform a vigorous effort that induces the release of cardiac damage markers. There are several factors that can affect the total number of these markers, so the aim of this review was to analyze the effect of endurance running races on cardiac damage markers and to identify the factors that modify the levels of segregation of these cardiac damage markers.

METHODS

A systematic search of PubMed, Web of Science, and the Cochrane Library databases was performed. This analysis included studies where the acute effects of running races on cardiac damage markers (troponin I and troponin T) were analyzed, assessing the levels of these markers before and after the races.

RESULTS

The effects of running races on troponin I (mean difference = 0.0381 ng/mL) and troponin T (mean difference = 0.0256 ng/mL) levels were significant. The ages (R² = 14.4%, p = 0.033) and body mass indexes (R² = 14.5%, p = 0.045) of the athletes had a significant interaction with troponin I. In addition, gender, mean speed, time to finish the race, and type of race can affect the level of cardiac damage markers.

CONCLUSION

Endurance running races induce the release of cardiac-damage markers that remain elevated for at least 24 h after the races. In addition, young male athletes with high body mass indexes who perform races combining long duration and moderate intensity (i.e., marathons) release the highest levels of cardiac damage markers. Physicians should take into consideration these results in the diagnosis and treatment of patients admitted to the hospital days after finishing endurance running races.

A longitudinal analysis of morphological characteristics and body proportionality in young elite sprint paddlers

Introduction: There are certain anthropometric attributes common to most high-level paddlers and among the determinants for optimal performance consecution in senior categories.Objective: The present investigation aimed to determine the evolution of morphological characteristics of elite paddlers during adolescence and to compare them with the values exhibited by Olympic competitors.Methods: In a longitudinal study, thirteen young elite paddlers (seven boys and six girls) completed a battery of anthropometric tests (heights, weight, girths, lengths, and sum of skinfolds) and on-water performance assessments (200 and 500 m) during three consecutive years.Results: Body mass and upper body sizes significantly change over the years (p < .05), especially in boys. Both male and female paddlers presented significant differences and large effect sizes in muscle mass and skin mass values (η²_p > .64) whereas bone mass and fat mass remained stable from the 1st to the 3rd year. Proportionality analysis revealed girths and breadths differences in arm and chest variables as well as large effect sizes in biacromial breadth among all years (η²_p > .62; p < .05), particularly in boys. Similarly, significant improvements in 200-m performance times were observed for both sexes.Conclusions: The findings of the current investigation might suggest a tendency towards a leaner and more robust morphological profile of elite paddlers in the transition from young to senior categories. In addition, the presence of superior relative body dimensions from young categories seems to be paramount in the evolution to later successful paddling.

Recovery of Heart Rate Variability After Exercise Under Hot Conditions: The Effect of Relative Humidity

INTRODUCTION

The aim of this study was to analyze changes in heart rate variability (HRV) during exercise in hot environments and recovery to baseline values depending on relative humidity.

METHODS

Ten recreational runners participated in this study. Each participant performed 2 trials consisting of 30 min of continuous running under hot and dry (HD) (38°C and 28% relative humidity) and hot and humid (HH) conditions (38°C and 64% relative humidity) at their common 10 km race-running rhythm. HRV and body mass were assessed pre- and post-trial; the rating of perceived exertion and HRV were assessed during the trial; and HRV measurements were repeated 2, 4, 8, and 24 h postexercise. Primary HRV outcomes were root mean square of the successive differences, high frequency power, stress score, and sympathetic/parasympathetic ratio. One-way analysis of variance testing was used to analyze differences.

RESULTS

No significant difference in body mass occurred across the different conditions or distances covered (P>0.05). Rating of perceived exertion presented the highest correlation values with stress score (r=0.729 for HD; r=0.568 for HH) and sympathetic/parasympathetic ratio (r=0.621 for HD; r=0.519 for HH) during exercise. HRV recovered to baseline values more quickly after exercising under dry conditions (4 h) than under humid conditions (between 8 and 24 h).

CONCLUSIONS

Stress score and sympathetic/parasympathetic ratio seem to be the best HRV predictors of internal load. Although there are no differences in HRV during recovery at the same time points in both conditions, the recovery is slower after exercise in HH than in HD.

Morphological and Physical Fitness Profile of Young Female Sprint Kayakers

López-Plaza, D, Alacid, F, Rubio, JÁ, López-Miñarro, PÁ, Muyor, JM, and Manonelles, P. Morphological and physical fitness profile of young female sprint kayakers. J Strength Cond Res 33(7): 1963-1970, 2019-Traditionally, physical and anthropometrical profiles of the most successful kayak athletes have been identified in male kayakers. This study attempted to identify the differences in morphology and fitness level of 2 performance-based groups of young elite female paddlers. Eighty-six female kayakers, aged 13.62 ± 0.57 years (mean ± SD), were allocated in 2 groups (Top-10 and Rest) depending on their ranking in the 3 Olympic distances (200, 500, and 1,000 m). All subjects underwent a battery of anthropometrical (heights, mass, girths, and sum of skinfolds), physical fitness (overhead medicine ball throw, countermovement jump, sit-and-reach test, and 20-m multistage shuttle run test), and specific performance assessments (200, 500, and 1,000 m). Best paddlers presented significantly greater anthropometrical values in muscle mass percentage, maturity status, and chronological age (p ≤ 0.05), whereas physical fitness comparison only revealed significant differences in countermovement jump (p ≤ 0.05). Furthermore, aerobic power and muscle mass percentage seem to be crucial in achieving optimal performances at long (1,000 m) and short duration races (200 and 500 m). These findings confirm the importance of a larger and compact morphology, as well as superior fitness level, for success in female kayakers. The current results not only identify the weak areas on body composition and physical fitness depending on the maturity status but also the development of specific training programs for females.

Physical activity, hydration and health

Since the beginning of mankind, man has sought ways to promote and preserve health as well as to prevent disease. Hydration, physical activity and exercise are key factors for enhancing human health. However, either a little dose of them or an excess can be harmful for health maintenance at any age. Water is an essential nutrient for human body and a major key to survival has been to prevent dehydration. However, there is still a general controversy regarding the necessary amount to drink water or other beverages to properly get an adequate level of hydration. In addition, up to now the tools used to measure hydration are controversial. To this end, there are several important groups of variables to take into account such as water balance, hydration biomarkers and total body water. A combination of methods will be the most preferred tool to find out any risk or situation of dehydration at any age range. On the other hand, physical activity and exercise are being demonstrated to promote health, avoiding or reducing health problems, vascular and inflammatory disea ses and helping weight management. Therefore, physical activity is also being used as a pill within a therapy to promote health and reduce risk diseases, but as in the case of drugs, dose, intensity, frequency, duration and precautions have to be evaluated and taken into account in order to get the maximum effectiveness and success of a treatment. On the other hand, sedentariness is the opposite concept to physical activity that has been recently recognized as an important factor of lifestyle involved in the obesogenic environment and consequently in the risk of the non-communicable diseases. In view of the literature consulted and taking into account the expertise of the authors, in this review a Decalogue of global recommendations is included to achieve an adequate hydration and physical activity status to avoid overweight/obesity consequences.