Influence of Prematch Perceived Wellness on High-Intensity Locomotor Activities of Professional Soccer Players During in-Season Matches

PURPOSE

The aim of this study was to determine the influence of prematch perceived wellness on high-intensity locomotor activities of professional soccer players during in-season matches.

METHODS

Twenty male soccer players (26.74 [3.27] y; 179.77 [6.06] cm; 76.72 [9.33] kg), members of a professional soccer team, participated in this longitudinal study. Data collection was conducted during the competitive period of 1 season and involved the 34 league official matches. Perceived wellness was assessed individually 3 hours before each match using a 5-point Likert questionnaire, and external loads during matches were monitored using global navigation satellite system devices. Each wellness item (ie, fatigue, delayed-onset muscle soreness [DOMS], sleep, and stress) was considered as an individual wellness component and analyzed as raw score, team z score, and individualized z score. Different random forest regression models and linear mixed models were carried out for statistical analysis.

RESULTS

Individualized z scores should be considered the most important variables to estimate the proportion of external-load variation during match play, but the proportion of the variance that may be explained from the prematch perceived wellness suggests a limited capacity in relation to external-load measures. Only individualized z scores of DOMS showed significant effects on sprint running distance (>24.0 km·h-1) and number of sprints (>24.0 km·h-1) during matches (P < .05).

CONCLUSIONS

Sprint performance of professional soccer players during in-season matches may be slightly influenced by the players' day-to-day variation of prematch perceived DOMS.

From Tissue to System: What Constitutes an Appropriate Response to Loading?

Optimal loading involves the prescription of an exercise stimulus that promotes positive tissue adaptation, restoring function in patients undergoing rehabilitation and improving performance in healthy athletes. Implicit in optimal loading is the need to monitor the response to load, but what constitutes a normal response to loading? And does it differ among tissues (e.g., muscle, tendon, bone, cartilage) and systems? In this paper, we discuss the "normal" tissue response to loading schema and demonstrate the complex interaction among training intensity, volume, and frequency, as well as the impact of these training variables on the recovery of specific tissues and systems. Although the response to training stress follows a predictable time course, the recovery of individual tissues to training load (defined herein as the readiness to receive a similar training stimulus without deleterious local and/or systemic effects) varies markedly, with as little as 30 min (e.g., cartilage reformation after walking and running) or 72 h or longer (e.g., eccentric exercise-induced muscle damage) required between loading sessions of similar magnitude. Hyperhydrated and reactive tendons that have undergone high stretch-shorten cycle activity benefit from a 48-h refractory period before receiving a similar training dose. In contrast, bone cells desensitize quickly to repetitive loading, with almost all mechanosensitivity lost after as few as 20 loading cycles. To optimize loading, an additional dose (≤ 60 loading cycles) of bone-centric exercise (e.g., plyometrics) can be performed following a 4-8 h refractory period. Low-stress (i.e., predominantly aerobic) activity can be repeated following a short (≤ 24 h) refractory period, while greater recovery is needed (≥ 72 h) between repeated doses of high stress (i.e., predominantly anaerobic) activity. The response of specific tissues and systems to training load is complex; at any time, it is possible that practitioners may be optimally loading one tissue or system while suboptimally loading another. The consideration of recovery timeframes of different tissues and systems allows practitioners to determine the "normal" response to load. Importantly, we encourage practitioners to interpret training within an athlete monitoring framework that considers external and internal load, athlete-reported responses, and objective markers, to contextualize load-response data.

Effect of Fitness Level on Time Course of Recovery After Acute Strength and High-Intensity Interval Training

ABSTRACT

Grammenou, M, Kendall, KL, Wilson, CJ, Porter, T, Laws, SM, and Haff, GG. Effect of fitness level on time course of recovery after acute strength and high-intensity interval training. J Strength Cond Res 38(12): 2055-2064, 2024-The aim was to investigate time course of recovery after acute bouts of strength (STR) and high-intensity interval training (HIIT). A secondary goal was to assess the influence of total fitness score (TFS), composed of handgrip strength and maximum aerobic power on recovery. Twenty-eight resistance-trained individuals completed 8 testing sessions within a 14- to 17-day period. Subjects performed a testing battery comprising isometric midthigh pull (IMTP), countermovement jump (CMJ), and a modified Wingate test (WINmod) at baseline, immediately after exercise, as well as at 6 and 24 hours after the training sessions. A one-way ANOVA was performed to examine time changes after the training sessions. Subjects were then grouped based on their TFS in high, medium, and low groups. To examine the influence of TFS on time course of recovery, we performed a linear mixed-effects model. Statistical significance was set at p < 0.05. Both training sessions resulted in a significant reduction in peak force (PF) that persisted for up to 6 (p < 0.05) and 24 hours (p < 0.001). The STR session showed immediate and 24-hour postexercise declines in jump height and reactive strength index modified (RSImod) compared with baseline. The low TFS group exhibited a significant RSImod reduction immediately after HIIT (p < 0.001), compared with the medium TFS group (p = 0.0002). In the STR session, the high TFS group displayed an increased eccentric displacement during CMJ 24 hours after exercise compared with baseline (p = 0.033). Overall, subjects with high TFS may be able to recover CMJ performance at the same rate as other TFS groups, despite performing more work.

Effects of Time Point of Pre-Competitions Peaking on Performance in Major-Competitions

Objectives: To study the effects of the time points of pre-competition peaking (TPCP, the time point when an athlete's peaking shows up before a major-competition) on the athletes' performances in the major-competition (M-Performance). Design: Mixed design. Methods: We used cluster analysis to classify 892 elite track and field athletes who participated in the 2017 and 2019 IAAF World Championships in Athletics, based on their TPCP and other related factors. Furthermore, we used a fixed-effects model and a mixed-effects model to analyze the relationship between the TPCP and M-Performance. Results: The TPCP of elite track and field athletes were divided into four categories: late, slightly late, slightly early, and early. In speed/power events, athletes in the slightly late category had better M-Performance. In endurance events, athletes in the slightly early category had better M-Performance. In speed/power events, delaying the TPCP did not improve the athletes' M-Performance. In endurance events, advancing the TPCP effectively improved the athletes' M-Performance. Conclusions: To improve M-Performance, athletes in speed/power events should be peaking 2-8 weeks before a major-competition, and athletes in endurance events should be peaking 8-14 weeks before a major-competition. Future research should aim to identify individual factors affecting TPCP, such as the time for the body's adaptation to training and the residual training effect.

Match-related fatigue in basketball: A systematic review

This study aimed to systematically review fatigue responses following basketball match-play and during congested match schedules, considering performance, physiological, athlete-reported, and sleep-related outcomes. Relevant articles published until 23 January 2024 were searched using Scopus, Web of Science, and SPORTDiscus. After screening, 44 studies were included in the systematic review. The main findings indicate that, in most cases, vertical jumping and linear sprinting showed significant decrements at match-end (<1 hour post-match) compared to pre-match [small-to-very large effect sizes (ES)], with persistent (≥1 hour post-match) impairments lasting 24-48 hours in jumping (only in males, small-to-very large ES) and linear sprinting (moderate-to-very large ES). Physiological changes generally included significant increases (moderate-to-very large ES) in cortisol and nutrient metabolism markers at match-end, alongside persistent increases in muscle damage (mainly at 13-72 hours post-match) and inflammation (13-48 hours). Finally, match-play generally increased muscle soreness (mainly at 24-48 hours, moderate-to-very large ES) and perceived fatigue (mainly at match-end), with unclear effects on mood, and no apparent impact on sleep-related outcomes. Research assessing congested match schedules is limited, although possible worsening in muscle damage, inflammation, perceived fatigue and well-being were observed in male players. Overall, these findings indicate an impairment in some of the reviewed performance, physiological, and athlete-reported outcomes.

Monitoring the detrimental impact of congested training periods on the strength levels and landing forces of young female aerobic gymnastics

Identifying indicators of non-functional overreaching during periods of increased training volume and/or intensity is particularly relevant for understanding the detrimental impacts incurred, as well as how these factors contribute to heightened injury risks among exposed athletes. This study aimed to compare the effects of a congested training period versus a standard training period on the strength levels and landing forces of female young aerobic gymnastics athletes. A prospective cohort study design was implemented, spanning four weeks. Fifty athletes (aged 16.2 ± 1.1 years old) at a trained/developmental level, competing at the regional level, were observed throughout the study. During two of these weeks (specifically weeks 2 and 3), half of the group was subjected to a congested training period consisting of six sessions per week (HTF), while the other half continued with their regular four sessions per week (STF). During each week of observation, participants underwent evaluation using the countermovement jump test (CMJ), squat jump test (SJ), and the leg land and hold test (LHT), with measurements taken on a force platform. The main outcomes repeatedly observed over the four weeks were CMJ peak landing force, CMJ peak power, SJ peak power, SJ maximum negative displacement, LHT time to stabilization, and LHT peak drop landing force. Significant interactions (time*group) were observed in CMJ peak power (p < 0.001), CMJ peak landing force (p < 0.001), SJ peak power (p < 0.001), SJ maximum negative displacement (p < 0.001), LHT time to stabilization (p < 0.001), and LHT peak drop landing force (p < 0.001). Furthermore, the results of the final assessment revealed significantly lower CMJ peak power (p = 0.008) and SJ peak power (p = 0.002) in the HTF group compared to the STF group. Additionally, significantly higher values of CMJ peak landing force (p = 0.041), SJ maximum negative displacement (p = 0.015), and LHT peak drop landing force (p = 0.047) were observed in the HTF group compared to the STF group. In conclusion, the increase in training frequency over two weeks significantly contributed to declines in neuromuscular power performance and peak landing forces. This indicates that intensified training periods may acutely expose athletes not only to performance drops but also to an increased risk of injury due to reduced capacity to absorb landing forces.

The effects of nature-based vs. indoor settings on the adaptability, performance and affect of calisthenics exercisers. A registered report

Comparisons of the beneficial effects of nature-based versus indoor physical activity have been extensively reported, but existing research addresses mainly aerobic activity (running, jogging), not resistance or mixed (aerobic and resistance) exercise. It is unclear if the psychological benefits extend to functionality, i.e., if participants perform their activities better in nature, and how movement is expressed in nature-based and indoor environments, during similar exercise. The present registered report was a randomized controlled trial investigating how engaging in similar resistance-based exercise (calisthenics) in nature-based and indoor settings differed in affective valence, perceived exertion, visual attention, movement adaptability, heart rate variability, and performance. Nature-based exercisers (N = 51) showed increased performance output than indoor exercisers (N = 53) (p < 0.001). There were no group differences in affective valence, perceived exertion, or visual attention. However, psychological states of nature-based exercisers showed stronger associations to performance output (r < 0.33) than those of indoor exercisers (r < 0.03). Nature-based exercisers' movement variability and structure, measured with non-linear and fractal techniques (Sample Entropy and Detrended Fluctuation Analysis), were more regular (p < 0.001) and more functionally adaptive (long-term Detrended Fluctuation Analysis, p = 0.022) to achieve better performance output. Heart rate variability measures were not different between groups. Distinct environments can influence movement adaptability in a calisthenics exercise routine, and ultimately contribute to better performance. These results show how action is specific to task environment, and how action implies not only the task, but also the characteristics of the environment. TRIAL REGISTRATION: NCT05090501 (Clinicaltrials.gov). Registered October 21, 2021.

Age-Associated Differences in Recovery from Exercise-Induced Muscle Damage

Understanding the intricate mechanisms governing the cellular response to resistance exercise is paramount for promoting healthy aging. This narrative review explored the age-related alterations in recovery from resistance exercise, focusing on the nuanced aspects of exercise-induced muscle damage in older adults. Due to the limited number of studies in older adults that attempt to delineate age differences in muscle discovery, we delve into the multifaceted cellular influences of chronic low-grade inflammation, modifications in the extracellular matrix, and the role of lipid mediators in shaping the recovery landscape in aging skeletal muscle. From our literature search, it is evident that aged muscle displays delayed, prolonged, and inefficient recovery. These changes can be attributed to anabolic resistance, the stiffening of the extracellular matrix, mitochondrial dysfunction, and unresolved inflammation as well as alterations in satellite cell function. Collectively, these age-related impairments may impact subsequent adaptations to resistance exercise. Insights gleaned from this exploration may inform targeted interventions aimed at enhancing the efficacy of resistance training programs tailored to the specific needs of older adults, ultimately fostering healthy aging and preserving functional independence.

The influence of sex-division, experience, and pacing strategy on performance in the 2020 CrossFit® Open

To observe workout pacing strategies and determine which best predicted performance, this retrospective study analyzed recorded efforts from a random selection of 160 high-ranking (top 10,000) men and women (n = 80 each) in the 2020 CrossFit® Open (CFO). Video recordings submitted to the official competition leaderboard for all five tests were analyzed to quantify overall test completion rates (and tie-break time for test 5 only) and within-test repetition completion rate (repetitions × sec-1) for each exercise, as well as the quantity of failed repetitions, break strategy (count and duration), and transition times. Each variable was aggregated into first-half, last-half, and total-test averages, slopes, and coefficient of variation; except on test 5 (total-test only). Spearman's rank correlation coefficients were calculated between test completion rates, each test's respective pacing variables, competitor demographics (height and body mass) and CFO experience (i.e., past participation, consecutive competitions, and ranks). Stepwise regression using significantly (p < 0.05) correlated variables produced two prediction models for test performance (best predictor only and best overall model within 8 variables) in a validation group (50% of valid efforts) and then cross-validated against remaining athletes. When no between-group differences were seen, data were combined and used to create the final prediction models for test 1 (r2adj = 0.64-0.96, SEE = 0.4-1.2 repetitions × sec-1), test 2 (r2adj = 0.28-0.85, SEE = 2.0-4.5 repetitions × sec-1), test 3 (r2adj = 0.49-0.81, SEE = 1.1-1.7 repetitions × sec-1), test 4 (r2adj = 0.63-0.78, SEE = 0.6-0.9 repetitions × sec-1), and test 5 (rate: r2adj = 0.71-0.84, SEE = 1.2-1.6 repetitions × sec-1; tie-break time: r2adj = 0.06-0.62, SEE = 1.4-2.3 min). Across the five 2020 CFO tests, the data suggested that repetition pace, breaking strategy, and/or consistency in completing calisthenic-gymnastics components (when prescribed) was most predictive of performance. However, their influence was affected by the complexity of prescribed resistance training exercises and their relative loads. Athletes should prioritize calisthenic-gymnastics components but divert attention to more complex resistance training exercises when prescribed at higher relative intensity loads. Neither previous competition experience nor sex-division altered the hierarchal importance of these considerations.

The effect of medical grade compression garments on the repeated-bout effect in non-resistance-trained men

NEW FINDINGS

What is the central question of this study? What are the effects of compression garments on recovery from unaccustomed damaging exercise and subsequent protective adaptations? What is the main finding and its importance? Compression did not influence recovery, but was associated with blunted protective adaptations for isokinetic performance, which were completely absent at high velocities. Based on these findings, the use of compression garments for recovery would not be recommended following unaccustomed exercise, particularly if the maintenance of high-velocity performance following exercise-induced muscle damage is desirable.

ABSTRACT

Whilst compression garments (CG) may enhance recovery from exercise-induced muscle damage (EIMD), many recovery strategies can attenuate adaptative responses. Therefore, the effects of CG on recovery from EIMD, and the rapid protective adaptations known as the repeated bout effect (RBE) were investigated. Thirty-four non-resistance-trained males (18-45 years) randomly received class II medical-grade CG or placebo for 72 h following eccentrically-focused lower-body exercise, in a double-blind, randomised controlled trial. Indices of EIMD were assessed at baseline, 0, 24, 48 and 72 h post-exercise, before exercise and testing were repeated after 14 days. Results were analysed using a three-way (time × condition × bout) linear mixed-effects model. Exercise impaired isometric and isokinetic strength, with soreness and thigh circumference elevated for 72 h (P < 0.001). Compression did not enhance recovery (P > 0.05), despite small to moderate effect sizes (ES, reported alongside 90% confidence intervals) for isokinetic strength (ES from 0.2 [-0.41, 0.82] to 0.65 [0.03, 1.28]). All variables recovered faster after the repeated bout (P < 0.005). However, RBE for peak isokinetic force was impaired in CG at 60° s-1 (group × bout interaction: χ2  = 4.24, P = 0.0395; ES = -0.56 [-1.18, 0.07]) and completely absent at 120° s-1 (χ2  = 16.2, P < 0.001, ES = -0.96 [-1.61, -0.32]) and 180° s-1 (χ2  = 10.4, P = 0.001, ES = -0.72 [-1.35, -0.09]). Compression blunted RBE at higher isokinetic velocities without improving recovery in non-resistance-trained males, potentially contraindicating their use following unaccustomed exercise in this population.

Monitoring Resistance Training in Real Time with Wearable Technology: Current Applications and Future Directions

Resistance training is an exercise modality that involves using weights or resistance to strengthen and tone muscles. It has become popular in recent years, with numerous people including it in their fitness routines to ameliorate their strength, muscle mass, and overall health. Still, resistance training can be complex, requiring careful planning and execution to avoid injury and achieve satisfactory results. Wearable technology has emerged as a promising tool for resistance training, as it allows monitoring and adjusting training programs in real time. Several wearable devices are currently available, such as smart watches, fitness trackers, and other sensors that can yield detailed physiological and biomechanical information. In resistance training research, this information can be used to assess the effectiveness of training programs and identify areas for improvement. Wearable technology has the potential to revolutionize resistance training research, providing new insights and opportunities for developing optimized training programs. This review examines the types of wearables commonly used in resistance training research, their applications in monitoring and optimizing training programs, and the potential limitations and challenges associated with their use. Finally, it discusses future research directions, including the development of advanced wearable technologies and the integration of artificial intelligence in resistance training research.

Cannabis use for exercise recovery in trained individuals: a survey study

BACKGROUND

Cannabis use, be it either cannabidiol (CBD) use and/or delta-9-tetrahydrocannabinol (THC) use, shows promise to enhance exercise recovery. The present study aimed to determine if individuals are using CBD and/or THC as a means of recovery from aerobic and/or resistance exercise, as well as additional modalities that might be used to aid in recovery.

METHODS

Following consent, 111 participants (Mean ± SD: Age: 31 ± 13 years) completed an anonymous survey. All participants were regularly using cannabis (CBD and/or THC) as well as were currently exercising. Questions pertained to level of cannabis use, methods used for consumption of cannabis, exercise habits, exercise recovery strategies, and demographics.

RESULTS

Eighty-five percent of participants reported participating in aerobic training. In addition, 85% of participants also reported regular participation in resistance exercise. Seventy-two percent of participants participated in both aerobic and resistance exercise. Ninety-three percent of participants felt that CBD use assisted them with recovery from exercise, while 87% of participants felt the same regarding THC use.

CONCLUSIONS

Individuals who habitually use cannabis, CBD or THC, and regularly engage in exercise do feel that cannabis assists them with exercise recovery. More data are necessary to understand the role of cannabis in exercise recovery as well as perceived ergogenic benefits of cannabis by individuals who both regularly participate in exercise and habitually use cannabis.

Validity and Accuracy of Impulse-Response Models for Modeling and Predicting Training Effects on Performance of Swimmers

PURPOSE

The aim of this study was to compare the suitability of models for practical applications in training planning.

METHODS

We tested six impulse-response models, including Banister's model (Model Ba), a variable dose-response model (Model Bu), and indirect-response models differing in the way they account or not for the effect of previous training on the ability to respond effectively to a given session. Data from 11 swimmers were collected during 61 wk across two competitive seasons. Daily training load was calculated from the number of pool-kilometers and dry land workout equivalents, weighted according to intensity. Performance was determined from 50-m trials done during training sessions twice a week. Models were ranked on the base of Aikaike's information criterion along with measures of goodness of fit.

RESULTS

Models Ba and Bu gave the greatest Akaike weights, 0.339 ± 0.254 and 0.360 ± 0.296, respectively. Their estimates were used to determine the evolution of performance over time after a training session and the optimal characteristics of taper. The data of the first 20 wk were used to train these two models and predict performance for the after 8 wk (validation data set 1) and for the following season (validation data set 2). The mean absolute percentage error between real and predicted performance using Model Ba was 2.02% ± 0.65% and 2.69% ± 1.23% for validation data sets 1 and 2, respectively, and 2.17% ± 0.65% and 2.56% ± 0.79% with Model Bu.

CONCLUSIONS

The findings showed that although the two top-ranked models gave relevant approximations of the relationship between training and performance, their ability to predict future performance from past data was not satisfactory for individual training planning.

Effects of Different Recovery Modalities on Delayed Onset Muscle Soreness, Recovery Perceptions, and Performance Following a Bout of High-Intensity Functional Training

The purpose of this study was to investigate the effects of the foam rolling technique and static stretching on perceptual and neuromuscular parameters following a bout of high-intensity functional training (HIFT), which consisted of 100 pull-ups, 100 push-ups, 100 sit-ups, and 100 air squats (Angie benchmark) in recreationally trained men (n = 39). Following baseline measurements (Feeling Scale, Visual Analogue Scale, Total Quality Recovery, Sit-and-Reach, Countermovement Jump, and Change-of-Direction t-test), the volunteers performed a single bout of HIFT. At the end of the session, participants were randomly assigned to one of three distinct groups: control (CONT), foam rolling (FR), or static stretching (SS). At the 24 h time-point, a second experimental session was conducted to obtain the post-test values. The level of significance was set at p < 0.05. Regarding power performance, none of the three groups reached pretest levels at 24 h point of the intervention. However, the CONT group still showed a greater magnitude of effect at the 24 h time-point (ES = 0.51, p ≥ 0.05). Flexibility presented the same recovery pattern as power performance (post × 24 h CONT = ES = 0.28, FR = ES = 0.21, SS = ES = 0.19). At 24 h, all groups presented an impaired performance in the COD t-test (CONT = ES = 0.24, FR = ES = 0.65, SS = ES = 0.56 p ≥ 0.05). The FR protocol resulted in superior recovery perceptions (pre × 24 h TQR = ES = 0.32 p ≥ 0.05). The results of the present study indicate that the use of FR and SS exercises may not be indicated when aiming to restore neuromuscular performance following a single bout of HIFT. The use of the FR technique during the cooldown phase of a HIFT session may be helpful in improving an individual's perception of recovery.

Repeated Massage Improves Swimmers' Perceptions during Training Sessions but Not Sprint and Functional Performance: A Randomized Controlled Trial

This study aimed to investigate the effects of repeated massage adjusted for swimmers' training on the perceptive, functional, and performance outcomes of a sprint. We also investigated the effects of a single short massage on swimmers' self-reported perceptions after resistance training. This cross-over randomized controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis included 19 male and female competitive swimmers between 12 and 20 years old. Participants were subjected to three 12-min interventions over a week between resistance and swim training and monitored regarding training load and perceptions. After the intervention week we assessed: perceptive (well-being, heaviness, tiredness, discomfort, and pain), performance (sprint time, FINA points, and stroke characteristics), and functional outcomes (flexibility, squat jump, bench press, proprioception), in addition to athlete beliefs and preferences. A massage was defined as consisting of sliding movements on the arms, back, and anterior thigh, with metronomic rhythm control (1:1), and was divided into two protocols: superficial massage (SM) (light touch) and deep massage (DM) (light, moderate, intense effleurage) while the control (CON) rested. After repeated massage (SM and SM), participants had less chances to report tiredness, and they also maintained perceptions of well-being while CON got worse throughout the week. However, we found evidence of worsening of the perceptions of heaviness and pain at the main stages of the swim training for the massage groups. SM and DM had no effects over sprint and functional performance. Our results suggest that the swimmers were able to train harder with no harm to recovery.

Ginseng Pectin WGPA Alleviates Exercise-Induced Fatigue by Enhancing Gluconeogenesis

With the development of medicine and sport science, growing attention has been paid to the recovery of exercise-induced fatigue. Ginseng pectin has been shown to be important for a variety of biological functions. Although many studies suggest that ginseng pectin plays an important role in the alleviation of exercise-induced fatigue, the underlying mechanism still remains unclear. In this study, C57BL/6J mice were subjected to a wheel apparatus for exhaustive exercise and fed with ginseng pectin WGPA (acidic fraction of water-soluble ginseng polysaccharides) afterwards. Subsequently, a series of physiological and biochemical indexes, such as blood lactic acid, blood glucose, muscle glycogen, insulin, and glucagon, is evaluated. Meanwhile, enzymatic activity and mRNA level of key enzymes involved in hepatic gluconeogenesis are analyzed. Our results demonstrate that the treatment of ginseng pectin WGPA can result in enhanced gluconeogenesis and decreased insulin and in turn facilitate the recovery of exercise-induced fatigue. In response to WGPA treatment, both phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6Pase) activity were upregulated, indicating that these two enzymes play a critical role in WGPA-induced upregulation in gluconeogenesis. Moreover, mRNA level of G6Pase, but not PEPCK, was increased upon WGPA treatment, suggesting that G6Pase expression is regulated by WGPA. Importantly, the presence of WGPA downregulated insulin both in vivo and in vitro, suggesting the upregulation in gluconeogenesis may be due to alterations in insulin. Together, we provide evidence that ginseng pectin WGPA is able to alleviate exercise-induced fatigue by reducing insulin and enhancing gluconeogenesis.

Understanding 'monitoring' data-the association between measured stressors and athlete responses within a holistic basketball performance framework

This study examined associations between cumulative training load, travel demands and recovery days with athlete-reported outcome measures (AROMs) and countermovement jump (CMJ) performance in professional basketball. Retrospective analysis was performed on data collected from 23 players (mean±SD: age = 24.7±2.5 years, height = 198.3±7.6 cm, body mass = 98.1±9.0 kg, wingspan = 206.8±8.4 cm) from 2018-2020 in the National Basketball Association G-League. Linear mixed models were used to describe variation in AROMs and CMJ data in relation to cumulative training load (previous 3- and 10-days), hours travelled (previous 3- and 10-day), days away from the team's home city, recovery days (i.e., no travel/minimal on-court activity) and individual factors (e.g., age, fatigue, soreness). Cumulative 3-day training load had negative associations with fatigue, soreness, and sleep, while increased recovery days were associated with improved soreness scores. Increases in hours travelled and days spent away from home over 10 days were associated with increased sleep quality and duration. Cumulative training load over 3 and 10 days, hours travelled and days away from home city were all associated with changes in CMJ performance during the eccentric phase. The interaction of on-court and travel related stressors combined with individual factors is complex, meaning that multiple athletes response measures are needed to understand fatigue and recovery cycles. Our findings support the utility of the response measures presented (i.e., CMJ and AROMs), but this is not an exhaustive battery and practitioners should consider what measures may best inform training periodization within the context of their environment/sport.

Long-Term Effect of Vibration Therapy for Training-Induced Muscle Fatigue in Elite Athletes

Purpose: To evaluate the long-term effect of vibration therapy with holistic and local intervention in treating muscle fatigue in elite athletes during their intensive training season. Methods: Study participants included five male athletes from a provincial Greco-Roman wrestling team who were qualified for the finals of China’s national games. During the study, conventional therapeutic intervention was applied during the initial three weeks of the study, and an instrument intervention was adopted in the following three weeks. A surface electromyography (sEMG) was used to measure muscle fatigue of latissimus dorsi, both before and after each intervention session. Specifically, the pre-intervention measurement was conducted right after the daily training completion; and the post-intervention measurement occurred in the following morning. The data analyses were to compare the differences in the muscle fatigue data between the two modes of interventions, conventional and instrument therapy. Results: The conventional intervention showed no significant difference in the sEMG indexes before and after the intervention; while for the instrument intervention, the pre- and post- intervention sEMG indexes differed significantly (p < 0.05). Conclusion: The long-term effects of instrument vibration therapy on muscle fatigue recovery were studied based on observational data from elite athletes. The results indicate that the vibration therapy with holistic and local consideration demonstrated an effective reduction of muscle fatigue and/or fatigue accumulation in elite athletes during their intensive training season.

Concurrent Training Programming: The Acute Effects of Sprint Interval Exercise on the Subsequent Strength Training

Exercise modality has been proposed to reduce the interferences between aerobic and resistance sessions during concurrent training. The aim of the study was to examine the acute effects of cycling or running sprint interval exercise on subsequent resistance training sessions. Twenty-five competitive male rugby union players were recruited. Players were tested during three conditions: CONTROL (resistance training session only), CYCLE and RUN (corresponding to a concurrent training scheme with cycling or running sprint interval exercise conducted on the morning, followed by a resistance training session). Four hours rest was proposed between the aerobic and resistance training session. Muscle performance (bar velocity during bench press and box squat, counter movement jump height) and subjective ratings (rate of perceived exertion, wellbeing) were assessed during and after aerobic or resistance training sessions. No significant difference was observed for muscle performance (vertical jump height and bar velocity). However, significant higher perceived exertion and low-value scaled subjective wellbeing were observed in RUN (7.7 ± 1.1 and 17.9 ± 4.1, respectively) as compared with the two other conditions (6.7 ± 1.5 and 21.1 ± 3.6 for CONTROL and 7.4 ± 1.1 and 20.1 ± 3.9 for CYCLE). It was concluded that the exercise modality (running or cycling) during the aerobic exercise using a sprint interval exercise did not impact the quality of the resistance session. However, subjective ratings were affected the following days. Cycling exercises might be more adequate when performing a sprint interval training session during concurrent training programs.

A lab-based comparison of differential ratings of perceived exertion between a run and jump protocol involving low or high impacts on the lower extremities

ABSTRACTThe rating of perceived exertion method allows to describe training intensity in a single value. To better understand the underlying components, the separate rating of perceived breathlessness (RPE-B) and leg-muscle exertion (RPE-L) has been proposed. Here we hypothesized that the separation between the two components may (partly) be determined by the impacts on the lower extremities. In this study, we aimed to experimentally evaluate the differential effect of high versus low impact running and jumping on RPE-B and RPE-L in team sport activities by manipulating the movement strategy (heel strike and passive landing pattern versus forefoot strike and active landing pattern). Eighteen recreational team sport players participated in two submaximal tests consisting of a sequence of running and jumping bouts, whilst ground reaction forces (GRF) were collected. RPE-B and RPE-L data were collected after each bout using the CR100 scale. Paired-samples t-tests were used to analyse between-session differences in these variables. GRF analysis showed that absorption mechanics differed considerably between the two sessions. RPE-L was on average 6.50 AU higher in the low impact session (p = 0.006). However, RPE-B was also increased by 4.96 AU with low impact (p = 0.009). We conclude that the extent to which the lower extremities are being exposed to high or low impacts does not explain a possible separation between the two RPE types.

Compression Garments for Recovery from Muscle Damage: Evidence and Implications of Dose Responses

ABSTRACT

The use of compression garments (CG) has been associated with improved recovery following exercise-induced muscle damage. The mechanisms responsible are not well established, and no consensus exists regarding the effects of compression pressure (i.e., the "dose"), which until recently was seldom reported. With the increasing prevalence of studies reporting directly measured pressures, the present review aims to consolidate current evidence on optimal pressures for recovery from exercise-induced muscle damage. In addition, recent findings suggesting that custom-fitted garments provide greater precision and experimental control are discussed. Finally, biochemical data from human trials are presented to support a theoretical mechanism by which CG enhance recovery, with recommendations for future research. The effects of compression on adaptation remain unexplored. More studies are required to investigate the relationship between compression pressure and the recovery of performance and physiological outcomes. Furthermore, improved mechanistic understanding may help elucidate the optimal conditions by which CG enhance recovery.

Effects of chronic betaine supplementation on performance in professional young soccer players during a competitive season: a double blind, randomized, placebo-controlled trial

OBJECTIVE

Various nutritional strategies are adopted for athletes to maintain and to improve performance during the competition season. Betaine may enhance performance during a competitive season by increasing the testosterone to cortisol ratio and reducing systemic inflammation. The aim of this study was to investigate the effect of betaine supplementation on the bio-motor abilities in young professional soccer players.

METHODS

Twenty-nine young professional soccer players (age, 15.5±0.3 years) were matched by position and randomly assigned to one of two groups for 14 weeks: betaine (BG, 2 g/day; n=14) or placebo (PG n=15). Diet was standardized by a nutritionist, and measures of muscular power (countermovement jump: CMJ), change of direction: modified 5-0-5), acceleration (10 m sprint), sprint performance (30 m sprint time: SpT), muscular strength (leg press and bench press one repetition maximum: 1-RM), repeated sprint ability (running-based anaerobic sprint test: RAST), and aerobic capacity (30-15 intermittent fitness test) were assessed in the pre (P1), mid (P2) and post (P3) season over the course of 5 days. All subjects participated in one soccer match and five training sessions per week.

RESULTS

Significant (p < 0.05) group x time interactions were found for maximal oxygen uptake (VO2max), anaerobic peak power, and muscular strength favoring BG at P2 and P3 compared to P1. There were meaningful (p < 0.05) group x time interactions for CMJ, SpT, and peak power during the RAST that favored the BG.

CONCLUSIONS

14-week of betaine supplementation increased predicted 1-RM, VO2max, and repeated sprint ability performance in youth professional soccer players. Betaine supplementation seems to be a useful nutritional strategy to improve and to maintain performance during a competitive soccer season.

Passive Recovery Strategies after Exercise: A Narrative Literature Review of the Current Evidence

ABSTRACT

Passive recovery techniques are popular and offer a diverse spectrum of options for athletes and the clinicians providing care for them. These techniques are intended to minimize the negative effects of training or competition, thus enabling the athlete a quicker return to peak performance. Current evidence demonstrates improved athlete recovery with compression garments, cold water immersion, partial body cryotherapy, hyperbaric oxygen, and vibratory therapies. Other popular modalities, such as compression devices, whole body cryotherapy, percussive gun-assisted therapy, neuromuscular electrical stimulation, and pulsed electromagnetic therapy lack convincing evidence concerning athlete recovery. This article seeks to review the current literature and offer the reader an updated understanding of the mechanisms for each modality and the evidence regarding each modality's potential benefit in an athlete's recovery strategy.

Workout Pacing Predictors of Crossfit® Open Performance: A Pilot Study

To observe workout repetition and rest interval pacing strategies and determine which best predicted performance during the 2016 CrossFit® Open, five male (34.4 ± 3.8 years, 176 ± 5 cm, 80.3 ± 9.7 kg) and six female (35.2 ± 6.3 years, 158 ± 7 cm, 75.9 ± 19.3 kg) recreational competitors were recruited for this observational, pilot study. Exercise, round, and rest time were quantified via a stopwatch for all competitors on their first attempt of each of the five workouts. Subsequently, pacing was calculated as a repetition rate (repetitions·s^-1) to determine the fastest, slowest, and average rate for each exercise, round, and rest interval, as well as how these changed (i.e., slope, Δ rate / round) across each workout. Spearman’s rank correlation coefficients indicated that several pacing variables were significantly (p < 0.05) related to performance on each workout. However, stepwise regression analysis indicated that the average round rate best predicted (p < 0.001) performance on the first (R² = 0.89), second (R² = 0.99), and fifth (R² = 0.94) workouts, while the competitors’ rate on their slowest round best predicted workout three performance (R² = 0.94, p < 0.001). The wall ball completion rate (R² = 0.89, p = 0.002) was the best predictor of workout four performance, which was improved by 9.8% with the inclusion of the deadlift completion rate. These data suggest that when CrossFit^® Open workouts consist of multiple rounds, competitors should employ a fast and sustainable pace to improve performance. Otherwise, focusing on one or two key exercises may be the best approach.

Autoregulation in Resistance Training: Addressing the Inconsistencies

Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties.

Sport medicine and safety at work

As humans become more and more sedentary, physical capacities also become lost along with aerobic fitness, muscular strength, coordination, and action-reaction time. This situation can lead to not only absence from work (back pain is the most common reason in European Union (EU), but especially, workplace accidents. In this article, we want to combine our experience with exercise physiology and physical capacities with our medical work in a critical environment. We tested over ten years, the fitness profile of 1200 Italian Alpine Soldiers, and gave them a scientific training program. We obtained a trained and homogeneous team (homogeneous, in terms of aerobic and anaerobic fitness). Here, we detail changes to aerobic and anaerobic fitness resulting because of soldiers’ participation in a training program. We consider this method necessary for safe work in a critical environment.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.