Monitoring training in athletes with reference to overtraining syndrome

Selected Immunoendocrine and Physiological Performance Adaptations to Different Volume of Upper-Body Plyometric Training in National-Level Male Volleyball Players

PURPOSE

This study aimed to investigate the impact of a 6-week upper-body plyometric-training (PT) program with varying volumes on the immunoendocrine, physiological parameters, and physical performance adaptations in male volleyball players.

METHODS

Twenty-four trained college players were randomly allocated into 3 groups with 8 participants. Each group performed 5 exercises at maximal effort with differences in volume: low (3 sets of 7 repetitions), moderate (3 sets of 10 repetitions), and high (3 sets of 13 repetitions). The training program lasted 6 weeks with participants undertaking 3 sessions of PT per week.

RESULTS

Following the intervention, all groups exhibited significant (P = .001) improvements in physical and physiological parameters, as well as skill-based performances, with effect sizes ranging from small to very large. Comparative analysis of individual changes indicated that the high-volume group resulted in greater adaptive responses in the medicine-ball throw (P = .004), peak (P = .001) and average (P = .022) power output, push-ups (P = .001), and strength (P = .032) compared with the low-volume group. No significant between-groups difference (P > .05) was observed regarding immunoendocrine measures, reaction time, attacking, and serving skills.

CONCLUSIONS

The findings indicate that short-term upper-body PT positively influenced performance adaptations, emphasizing that the adaptive response to PT depends on the varying volumes. The study proposes that integrating higher volumes of PT results in more significant adaptive responses among volleyball players with the same immunoendocrine responses as the other training volumes.

Morning sprint interval training produces greater physical performance adaptations than evening training in soccer players

While the literature provides evidence supporting the effectiveness of evening sprint interval training (SIT), there remains a limited amount of research investigating the effects of morning SIT among soccer athletes. This study examined the effects of morning versus evening SIT during the preparatory phase on physical and physiological performance in collegiate soccer players. Thirty male players volunteered to participate in the study and were randomly divided into morning, evening, or control groups, each group consisting of 10 subjects. The evaluation of physical (countermovement vertical jump [CMVJ], 20-m sprint, Illinois change of direction, and Yo-Yo intermittent recovery test level 1 [Yo-Yo IR1]) and physiological (graded exercise test and Wingate anaerobic power test) performance took place prior to and following the 7-week SIT, both in the morning and evening testing sessions. Both training groups showed significant improvements in physical and physiological performance from pre- to post-training, regardless of testing session timing (p < 0.05). The morning SIT group exhibited greater adaptive changes (p < 0.05) compared to the evening SIT group in CMVJ, 20-m sprint, Yo-Yo IR1, peak and mean power outputs at both the morning and evening testing sessions. These findings suggest that male soccer players can benefit from both morning and evening SIT sessions; however, conducting SIT in the morning could result in greater adaptive changes than evening training. To optimize physical performance adaptations, coaches should schedule SIT sessions in the morning. It is recommended to schedule conditioning workouts in the morning and team practices in the afternoon for optimal adaptations.

Duration-dependent physiological, perceptual, and technical changes during a 2-hour low-intensity training session in female cross-country skiers

Purpose

This study investigated duration-dependent physiological, perceptual, and technical changes during a 2-hour low-intensity training (LIT) session in female cross-country (XC) skiers.

Methods

Twelve national-level female XC skiers (age:21.4 ± 2.7 years, maximal oxygen uptake: 58.1 ± 5.3 mL min⁻1·kg⁻1) performed a 2-hour LIT session, roller-ski skating in the laboratory while alternating between two main sub-techniques (Gear-2 and Gear-3). Acute physiological and perceptual responses, including oxygen uptake, carbon dioxide production, ventilation, breathing frequency, respiratory exchange ratio, blood lactate concentration, and rate of perceived exertion, as well as kinematic variables (cycle length and cycle rate), were collected at four consecutive timepoints (T1-T4) for both sub-techniques. A post-session questionnaire collected data on perceived total, ventilatory, and mental exertion as well as perceived training quality.

Results

Relatively small duration-dependent changes were observed for most of the physiological measures. The most pronounced changes were a main effect of time on breathing frequency (BF; F (3,30) = 3.52, ηp2 = 0.260, P = 0.027) and rate of perceived exertion (RPE; F (3, 33) = 4.43, ηp2 = 0.287, P = 0.010). More specifically, BF was higher in Gear-3 at both T2 (45.5 ± 7.7 breaths·min-1) and T3 (45.5 ± 7.7), compared to T1 (43.2 ± 7.3, all P < 0.05). Furthermore, the rate of perceived exertion was higher in both Gear-2 and Gear-3 at T2 (G2: 12.1 ± 1.0, G3: 11.2 ± 1.6) and T3 (G2: 12.2 ± 1.1, G3: 11.2 ± 1.6), compared to T1 (G2: 11.5 ± 1.2, G3: 10.6 ± 1.2, all P < 0.05). No differences were observed in kinematic variables (cycle length and cycle rate) between T1 - T4. Lastly, no differences in perceived total, ventilatory, and mental exertion, as well as perceived training quality, were observed between the first and second half of the LIT session.

Conclusion

Well-trained female XC skiers performed a 2-hour LIT session while roller-ski skating in the laboratory with relatively small duration-dependent physiological, perceptual, and technical changes.

Non-modifiable and modifiable factors affecting anxiety and depressive symptoms in young athletes

OBJECTIVES

The aim of the present study was to verify the association between non-modifiable (age categories, sex and race/ethnicity) and modifiable (sport modality, socioeconomic, training load, sleep, and eating disorder) factors with anxiety and depressive symptoms in young athletes.

METHODS

The sample was composed of 168 athletes engaged in national competitions from individual sports [swimming (n = 26) and badminton (n = 53)] and team sports [soccer (n = 28) and handball (n = 61)]. The coaches monitored the training load throughout the training week, and athletes completed self-reported questionnaires to assess sociodemographic data, sleep quality, eating disorders, and symptoms of anxiety and depression on the recovery day after a full week of pre-season training.

RESULTS

The prevalence of anxiety and depressive symptoms in young athletes were 14.3% and 25.6%, respectively, and female athletes presented higher rates of anxiety symptoms than males (30.8% vs. 11.3%; p = 0.015). Athletes from individual sports and athletes with 18 years or older showed higher depressive symptoms than younger (32.3% vs. 17.3%; p = 0.021). Athletes from the minority group showed higher depressive symptoms compared to the dominant group (41.9% vs. 20%; p = 0.005). The quality of sleep also influenced both anxiety (β = 5.430 [95%CI: 1.896 to 15.553]) and depressive symptoms (β = 5.292 [95%CI: 2.211 to 12.664)] in young athletes.

CONCLUSION

In short, non-modifiable factors, such as sex and age categories, should be considered when anxiety and depressive symptoms are examined in young athletes. Modifiable factors such as sports modality and sleep quality impact depressive symptoms in this population.

Session Rating of Perceived Exertion Is a Valid Method to Monitor Intensity of Exercise in Adults with Acute Burn Injuries

Measuring exercise intensity for safety and to inform prescription in acute burn survivors, is challenging. This study aimed to assess the validity of adult patient end-of-workout rating of session perceived exertion (sRPE); and calculated training load (TL) (sRPE × session duration) as measures of exercise intensity. Secondly, the study aimed to compare clinician and patient perception of exercise effort during physiotherapist-led sessions. Repeated RPE data were collected every 5-min during two resistance exercise sessions completed by 25 burns patients. Physiological (heart rate [HR], blood lactate [BLa]) and perceptual measures (sRPE, ratings of pain, fatigue, delayed onset muscle soreness, sleep quality and stress) were also captured. Adjusted, multivariable linear regression models were used to determine the associations between sRPE and TL and significant predictor variables. Paired t-tests were performed to compare clinician and participant sRPE. Results: Average RPE calculated from 5-min repeats, after adjustment for age and %TBSA, was significantly associated with sRPE, F(1, 45) = 100.82, (p < 0.001, adjusted R2 = 0.64) and TL, F(1, 45) = 33.66, (p < 0.001, adjusted R2 = 0.39). No significant differences between patient and clinician sRPE were apparent (p = 0.948). Thus, one-off reporting of sRPE and calculated TL may be appropriate markers to monitor exercise intensity and aid prescription in individuals with burn injuries, regardless of patient and burn characteristics or time since burn. There was also no difference between patient and clinician's perceptions of exercise effort.

Associations between subjective and objective measures of stress and load: an insight from 45-week prospective study in 189 elite athletes

Introduction

The aim of this study was to investigate the associations between subjective and objective measures of stress and load in elite male handball players at both the group and individual levels.

Methods

In this 45-week prospective cohort study, 189 elite male handball players weekly reported their perceived stress and load across training, competition, academic, and work domains. Blood samples were collected five times during the 2022/23 season to measure cortisol and the free testosterone to cortisol ratio (FTCR). We derived a "load" variable as the sum of training, competition, academic and work hours and calculated acute, chronic, and acute-to-chronic ratio variables for both load and stress. Associations between subjective and objective measures were analyzed using Spearman's rank correlation.

Results

Weak to moderate positive associations were found between load and perceived stress (r = 0.19 to 0.46, p < 0.001), and between perceived stress and cortisol (r = 0.10, p = 0.023). Weak negative associations were found between perceived stress and FTCR (r = -0.18 to -0.20, p < 0.001) and between load and FTCR (r = -0.13, p = 0.003). A total of 86% of athletes had positive associations between stress and load (47% weak, 34% moderate, 5% high); 78% between stress and cortisol (27% weak, 22% moderate, 29% high); and 63% demonstrated negative associations between FTCR and load (18% weak, 32% moderate, 13% high).

Conclusion

This study highlights the complexity between subjective and objective measures of stress and load in athletes. Understanding the link between these measures may help coaches and sports scientists streamline athlete monitoring. In cases where moderate to strong associations exist, subjective measures might serve as a reliable substitute for objective ones, making the monitoring process more time- and cost-efficient.

Exercise Immunology Applied to Pediatric Sport and the Importance of Monitoring Stages of Puberty and Biological Maturation

CONTEXT

Exercise immunology is aimed at understanding how exercise sessions can affect the immune system in athletic subjects of different age groups. The objective of the current study was to discuss in which stage of biological maturation (BM) young athletes may be more vulnerable in relation to the immune system, and whether there is a BM range in which it is safer to perform sports training with strenuous exercise loads.

EVIDENCE ACQUISITION

Evidence from scientific research from several scientific disciplines (eg, immunology, sport immunology, pediatrics, sports medicine, human development) was gathered to holistically examine the main particularities of exercise immunology as applied to pediatric sport.

STUDY DESIGN

Narrative review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

In pediatric patients, lymphoid tissue expands during puberty and involutes after puberty until it returns to pre-expansion values. This suggests that there is a specific period in which the immune system may be stronger, which may provide opportunities for strenuous exercise in pediatric athletes. However, the chronological period when puberty occurs will be determined by BM, which is the rate at which the biological systems of the human body improves. This may affect the period of lymphoid tissue expansion and, consequently, the behavior of the immune system in pediatric subjects of the same age category.

CONCLUSION

During puberty, there is a significant increase in the proinflammatory profile; to compensate for this, there is an expansion of lymphoid tissue that may favor the efficiency of the immune system. The period in which puberty is reached may vary according to the stages of BM. Therefore, in exercise immunology applied to pediatric sports, in addition to external and internal training loads, it is necessary to consider BM and puberty, which have been shown to be safer biomarkers than chronological age for determining immune system behavior in pediatric athletes.

STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT)

Evidence B level 3.

Acute effects of different physical activity on executive function and regulation role of beta oscillation in sedentary youth frontal region

Chronic sedentary behavior can have a negative impact on the executive function (EF) of young people. While physical activity (PA) has been shown to improve this phenomenon, the effects of different types of PA on EF vary. In this study, we compared the effects of moderate-intensity continuous training (MICT) (60-70% HRmax, 30 min), body weight training (BWT) (2 sets tabata, 20 min), and mind-body exercise (MBE) (2 sets Yang style shadowboxing, 20 min) on EF in 59 sedentary youth (n = 59, age = 20.36 ± 1.78, BMI = 24.91 ± 1.82, P>0.05) to identify the optimal dose of PA for improving EF. Metrics related to the EF task paradigm included stop signal, electroencephalogram (EEG), event-related potential (ERP), P300, N200, error-related negativity (ERN), and error positivity (Pe). error positivity (Pe), and β-wave in frontal lobe; training monitoring, including heart rate (HR), rating of perceived exertion (RPE), feeling scale (FS), and dual-mode model (DMM); load assessment, including Edward's TRIMP (TRIMP) and session-RPE (s-RPE). The study results indicate that BWT significantly improved accuracy in terms of EF (F = 16.84, P = 0.0381) and was comparable to MICT in terms of shortening reaction time (F = 58.03, P = 0.0217; F = 75.49, P = 0.0178). Regarding ERP, BWT reduced the amplitude values of N200 compared to ERN (F = 44.35, P = 0.0351; F = 48.68, P = 0.0317), increased P300 compared to Pe (F = 97.72, P<0.01; F = 29.56, P = 0.0189), and shortened P300 latency (F = 1.84, P = 0.0406). In contrast, MICT was only effective for P300 with Pe (F = 66.59, P = 0.0194; F = 21.04, P = 0.0342) and shortened N200 latency (F = 27.29, P = 0.0411). The increase in total amplitude and β-oscillation in terms of EEG was proportional to the exercise intensity, with the difference between MICT and BWT being present at 5-20 Hz, and MBE at 10-15 Hz. Regarding training load, the order of HR, RPE, TRIMP, and s-RPE was BWT > MICT > MBE (F = 202.69; F = 114.69; F = 114.69; P = 0.0342). The latency of N200 was also shortened (F = 27.29, P = 0.0411). The results showed that PA improves EF in sedentary youth, although BWT works best, it leads to a decrease in motor perception. Initially, MICT was scheduled alongside MBE and later replaced with BWT. This may help establish an exercise habit while improving EF.

Critical Fluctuations as an Early Warning Signal of Sports Injuries? A Proof of Concept Using Football Monitoring Data

BACKGROUND

There has been an increasing interest in the development and prevention of sports injuries from a complex dynamic systems perspective. From this perspective, injuries may occur following critical fluctuations in the psychophysiological state of an athlete. Our objective was to quantify these so-called Early Warning Signals (EWS) as a proof of concept to determine their explanatory performance for injuries. The sample consisted of 23 professional youth football (soccer) players. Self-reports of psychological and physiological factors as well as data from heart rate and GPS sensors were gathered on every training and match day over two competitive seasons, which resulted in an average of 339 observations per player (range = 155-430). We calculated the Dynamic Complexity (DC) index of these data, representing a metric of critical fluctuations. Next, we used this EWS to predict injuries (traumatic and overuse).

RESULTS

Results showed a significant peak of DC in 30% of the incurred injuries, in the six data points (roughly one and a half weeks) before the injury. The warning signal exhibited a specificity of 95%, that is, correctly classifying non-injury instances. We followed up on this promising result with additional calculations to account for the naturally imbalanced data (fewer injuries than non-injuries). The relatively low F1 we obtained (0.08) suggests that the model's overall ability to discriminate between injuries and non-injuries is rather poor, due to the high false positive rate.

CONCLUSION

By detecting critical fluctuations preceding one-third of the injuries, this study provided support for the complex systems theory of injuries. Furthermore, it suggests that increasing critical fluctuations may be seen as an EWS on which practitioners can intervene. Yet, the relatively high false positive rate on the entire data set, including periods without injuries, suggests critical fluctuations may also precede transitions to other (e.g., stronger) states. Future research should therefore dig deeper into the meaning of critical fluctuations in the psychophysiological states of athletes.

KEY POINTS

Complex Systems Theory suggests that sports injuries may be preceded by a warning signal characterized by a short window of increased critical fluctuations. Results of the current study showed such increased critical fluctuations before 30% of the injuries. Across the entire data set, we also found a considerable number of critical fluctuations that were not followed by an injury, suggesting that the warning signal may also precede transitions to other (e.g., healthier) states. Increased critical fluctuations may be interpreted as a window of opportunity for the practitioner to launch timely and targeted interventions, and researchers should dig deeper into the meaning of such fluctuations.

Effects of Explosive vs. Strength Resistance Training on Plantar Flexor Neuromuscular and Functional Capacities in Institutionalized Older Adults: A Randomized Controlled Trial

OBJECTIVES

To compare the effects of explosive and strength resistance training on neuromuscular and functional parameters in older adults and to analyze the relationship between changes in walking speed and improvements in plantar flexor (PF) neuromuscular parameters following interventions.

METHODS

In total, 40 participants were randomly assigned to either an explosive resistance training group (EXG, n = 18; age = 80.41 ± 10.12 years; body mass index = 22.89 ± 2.77 kg/m2) or a strength resistance training group (STG, n = 22; age = 82.89 ± 5.32 years; body mass index = 23.81 ± 3.45 kg/m2). Both groups participated in the same PF resistance training regimen (three sessions per week for 12 weeks), engaging in identical exercises. However, EXG performed three to five sets of 12 to 14 repetitions at 40% to 45% of one-maximal repetition with a rapid concentric phase and a 3 s eccentric phase, while the STG performed three to four sets of 6 to 7 repetitions at 80% to 85% of one-maximal repetition, with both phases lasting approximately 3 s. Before and after the interventions, gait speed (m/s) was assessed using a 10 m walking test, and relative maximal force (Relative Fmax, N/kg) was evaluated during maximal voluntary isometric contraction of PF. From the force-time curve, early (0-50 ms) and late (100-200 ms) rates of force development (RFD) were extracted from the linear slopes (Δ force/Δ time).

RESULTS

Gait speed significantly improved in both groups (p < 0.05). However, the improvement was more pronounced in the EXG compared to the STG (p < 0.05). Relative Fmax showed a more significant increase in the STG than in the EXG (p < 0.05). Moreover, a significant 10% increase in early RFD in the STG and a 20.1% increase in the EXG were observed (p < 0.05). The improvement in early RFD was greater in the EXG (p < 0.05). Additionally, late RFD improved significantly only in the EXG (+20.4%, p < 0.05).

CONCLUSION

Explosive resistance training appears particularly effective in improving the ability to rapidly generate force, which is essential for many daily activities requiring explosive movements and quick responses.

Serendipity in Science: 50+ Years of Designed, and Sometimes Lucky, Science

Normal science is about assessing what is already known about a topic, about what needs to be known, and careful methods to collect the data required to answer the scientific question. It is the mainstay of scientific progress. But sometimes, luck or chance (eg, serendipity) plays a significant role in scientific process. We trace career experiences in our lives to show how serendipity, the gift that Mother Nature gives to science, has a nontrivial role in scientific progress and professional careers. This gift often encourages us to change the focus of experiments or to look for the answers to our questions in ways that were not immediately obvious.

Implementation and Evaluation of a 10-Week Kettlebell Training Load Distribution on Strength and Aerobic Capacity in Recreationally Trained Women

Objective

: The purpose of this study was to characterize the dynamic distribution of training loads in a kettlebell program and evaluate its effects on muscle strength and aerobic capacity.

Methods

Fourteen recreationally active women with no kettlebell training experience (age: 25.86 ± 5.35 years; V̇O2max = 35.14 ± 5.58 mL/kg/min; body mass = 62.13 ± 13.40 kg; height = 164.75 ± 5.77 cm; body mass index = 22.68 ± 3.99 kg/m²) completed a 10-week kettlebell training program. The kettlebell training program was divided into three phases: Phase I (2 weeks), phase II (4 weeks), and Phase III (4 weeks). Maximum muscle strength (1RM) and aerobic fitness (V̇O2max) measurements were performed before (Pre) and after (Post) training. The external and internal loads were represented by the session's total volume and perceived exertion method.

Results

An increase in maximum strength (P < .001; ∆% = 23.73; effect size = 0.87) and V̇O2max (P = .004; ∆% = 9.63; effect size = 0.57) was observed when comparing Pre and Post measurements. There was an increase in total volume when phases I and II (P < .001), phases I and III (P < .001), and phases II and III (P < .001) of the training were compared. The internal load values increased significantly between phases I and II (P < .001). However, there was no difference when comparing phases II and III (P = .796).

Conclusion

The total volume increases during the training phases, and the training load was similar in phases II and III. Furthermore, were observed higher V̇O2max and strength (1 RM load) values.

Secondary injury prevention reduces hamstring strain and time-loss groin injury burdens in male professional football

OBJECTIVES

This study aimed to assess the effectiveness of a systems-based secondary injury prevention intervention aimed at early detection and management of hamstring strain injury (HSI) and time-loss groin injury in an Australian male professional football club.

DESIGN

Prospective cohort study.

SETTING

Australian male professional football club.

PARTICIPANTS

Data were collected from male professional football players (n = 73) from a single football club.

MAIN OUTCOME MEASURES

Unilateral knee flexion and side-lying hip adduction maximum voluntary isometric contractions were monitored routinely in-season, two days post-match (≥40 h [h]) during a three-season intervention period. Strength reductions greater than the tests' minimal detectable change percentage prompted intervention. HSI and time-loss groin injury burdens were calculated per 1000 player hours and compared with those from an immediately preceding two-season control period, to assess the effectiveness of the intervention.

RESULTS

Across the intervention period, there was a decrease in HSI (4.98 days absence/1000 h (19.8%) decrease) and time-loss groin injury burdens (0.57 days absence/1000 h (49.1%) decrease) when compared with the control period.

CONCLUSIONS

A systems-based secondary injury prevention intervention shows preliminary positive findings in reducing HSI and time-loss groin injury burdens within a male professional football club, compared with usual care only.

Relationship between external and internal load indicators and injury using machine learning in professional soccer: a systematic review and meta-analysis

This study verified the relationship between internal load (IL) and external load (EL) and their association on injury risk (IR) prediction considering machine learning (ML) approaches. Studies were included if: (1) participants were male professional soccer players; (2) carried out for at least 2 sessions, exercises, or competitions; (3) correlated training load (TL) with non-contact injuries; (4) applied ML approaches to predict TL and non-contact injuries. TL included: IL indicators (Rating of Perceived Exertion, RPE; Session-RPE, Heart Rate, HR) and EL indicators (Global Positioning System, GPS variables); the relationship between EL and IL through index, ratio, formula; ML indicators included performance measures, predictive performance of ML methods, measure of feature importance, relevant predictors, outcome variable, predictor variable, data pre-processing, features selection, ML methods. Twenty-five studies were included. Eleven addressed the relationship between EL and IL. Five used EL/IL indexes. Five studies predicted IL indicators. Three studies investigated the association between EL and IL with IR. One study predicted IR using ML. Significant positive correlations were found between S-RPE and total distance (TD) (r = 0.73; 95% CI (0.64 to 0.82)) as well as between S-RPE and player load (PL) (r = 0.76; 95% CI (0.68 to 0.84)). Association between IL and EL and their relationship with injuries were found. RPE, S-RPE, and HR were associated with different EL indicators. A positive relationship between EL and IL indicators and IR was also observed. Moreover, new indexes or ratios (integrating EL and IL) to improve knowledge regarding TL and fitness status were also applied. ML can predict IL indicators (HR and RPE), and IR. The present systematic review was registered in PROSPERO (CRD42021245312).

What gaps exist in biomechanics and motor control research in Paralympic sports? A scoping review focussed on performance and injury risk

In Paralympic sport, athletes, coaches and administrators seek medal-winning outcomes. Research in the fields of biomechanics and motor control can support the quantification of performance measures and injury risk. The aim of this article is to review the state of existing research and identify gaps offering researchers and practitioners targeted paths for creating competitive advantages. This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR). Four electronic databases were searched in accordance with selected terms and inclusion/exclusion criteria. A custom data charting matrix was used to identify relevant characteristics. From the 3363 retrieved articles, 237 studies covering 24 Paralympic sports were included. A new metric, medal events per included study (MEPIS), was developed. Research gaps were identified in the sports studied, impairment types, gender balance, the injury reduction process, and the application of motor control research, leading to suggested directions targeting Paralympic success.

Monitoring training load and perceived recovery indicators during the preseason and in-season phases in professional female basketball players

BACKGROUND

During the basketball season, it is essential to carefully plan training and recovery activities to optimize players' performance. This study monitored training load and perceived recovery indicators in professional female basketball players across the preseason and in-season phases.

METHODS

Seventeen professional female basketball players (age: 19.6±3.1 years; height: 180.2±5.9 cm; playing position: 8 backcourt, 9 frontcourt) were monitored for eleven consecutive weeks. Each morning, players reported their perceived recovery using a 10-point Total Quality of Recovery (TQR) Scale. After each training session or game, players reported their perceived exertion using the CR-10 Scale, which was multiplied by the duration of the training or game to obtain the session load. Weekly load, monotony, strain, TQRAM (morning recovery) and TQRfw (recovery at the start of the following week) were calculated. Linear mixed models were performed to assess the effects of season phase (preseason; in-season), playing position (backcourt; frontcourt) and group (senior; under) on load and recovery variables.

RESULTS

Weekly load, monotony and strain were higher in the preseason than the in-season phase (all P<0.001, ES: moderate-large). Strain was higher in senior players compared to under (P=0.045, ES: small). Regarding recovery variables, no effects were found for TQRAM, while TQRfw was higher in the preseason than in-season (P<0.001, ES: moderate) phase.

CONCLUSIONS

Professional female basketball players experience lower internal loads but poorer perceived recovery during the in-season phase. Practitioners should carefully consider the stress of competition and the cumulative fatigue from high preseason loads during the transition from the preseason to the regular season.

Athlete Monitoring Systems in Elite Men's Basketball: Challenges, Recommendations, and Future Perspectives

Athlete monitoring systems (AMSs) provide a centralized platform for integrating, processing, analyzing, and graphing various monitoring data to help coaches manage the rigorous demands of elite men's basketball players, who frequently participate in high-stress games with minimal recovery time. This review synthesizes current challenges in deploying AMSs, underscores their role in injury prevention and performance optimization, and discusses technological advances that could enhance their utility. Key challenges include selecting appropriate monitoring methods based on human and financial resources, accuracy of data collection, real-time data processing, and personalization of training regimens. Due to the weaknesses and limitations of each monitoring method, it is recommended that both objective (e.g., external load data, heart rate measures, and biomarkers) and subjective (athlete-reported outcome measures) monitoring data be integrated into an AMS to provide a holistic insight of the athlete's health and readiness. In addition, decision support systems integrated into an AMS can help coaches quickly gain an overview of their players' current condition and make informed decisions about daily load and recovery management. In this context, future perspectives suggest the potential for AMSs to incorporate predictive analytics and artificial intelligence to further enhance decision-making processes in elite men's basketball. Our findings underscore the need for continued innovation and rigorous validation of AMS technologies to ensure they meet the evolving demands of professional sports environments.

The effects of strength vs. plyometric training on sprinting kinetics in post peak height velocity (PHV) female athletes

Speed is a crucial factor for overall athletic development. While researchers have shown strength and plyometric training to improve sprinting speed in some adult and youth populations, no studies have compared the effects of strength and plyometric training on sprinting speed in young females. Fifty-two young females were divided into three groups and trained for 7 weeks, twice a week; strength training (n = 16, age 13.36 ± 0.84), plyometric training (n = 21, age 13.38 ± 0.75) and a physical education class as a control group (n = 15, age 13.95 ± 0.54). Participants were tested for sprinting performance and horizontal force (Fo), maximum velocity (Vmax) and maximum horizontal power (Pmax) metrics over 30 m distance, isometric strength and unilateral horizontal jump distance before and after the intervention. Both the strength and plyometric groups significantly improved all performance variables (p < 0.05). The strength group significantly improved 10 m split time (6.76%; Hedge's g = 0.65) and Fo (18.98%; g = 0.67), whereas the plyometric group significantly improved Vmax (4.91%; g = 0.50) and Pmax (7.91%; g = 0.31). The findings of this study suggest that both strength and plyometric training can improve sprinting kinetics, jumping performance and overall strength in young females.

Injury Risk in Elite Young Male Soccer Players: A Review on the Impact of Growth, Maturation, and Workload

ABSTRACT

Ribeiro, N, Martinho, DV, Pereira, JR, Rebelo, A, Monasterio, X, Gonzalo-Skok, O, Valente-dos-Santos, J, and Tavares, F. Injury risk in elite young male soccer players: a review on the impact of growth, maturation, and workload. J Strength Cond Res 38(10): 1834-1848, 2024-The long-term development of young male soccer players involves a prolonged period of significant adjustments, highlighting the importance of studying the complex interaction between dynamic variables, including workload, and inherent elements like growth and maturity. This analysis examines the intricate connections involving the development, maturity, workload, and susceptibility to injuries among adolescent male soccer players. Significantly, these connections become prominent at the peak height velocity (PHV) period, a crucial moment in maturation. Growth rates vary among individuals, and higher rates have been associated with an increased risk of injury in young soccer players, particularly during periods of rapid growth. Identifying possible risk factors and understanding the complex connections between them is crucial to developing specific methods for reducing the risk of injury. Sharing this valuable information with essential stakeholders is crucial for guaranteeing young athletes' comprehensive growth and maturation process. Furthermore, this review emphasizes the immediate need for long-term studies and thorough injury analyses to comprehend better the dynamic interactions that influence injury patterns in young male soccer players. This review will allow practitioners to better understand the main modifiable and nonmodifiable risk factors for injury and provide essential information focusing on practical strategies, facilitating more informed decision making by all stakeholders. The review aims to clarify these complexities and offer crucial insights that can assist in designing and implementing efficient strategies to reduce the risk of injury, specifically for the challenges faced during PHV and within the broader framework of long-term athletic development in young soccer.

Chronobiological Insights in Plyometric Jump Training: Optimizing Sport-Performance Adaptations for Volleyball Players

PURPOSE

The objective of this study was to investigate the effects of morning versus evening plyometric training (PT) on performance adaptations in male volleyball players.

METHODS

A total of 30 collegiate national-level young male volleyball players (age = 21.9 [2.1]; height = 186 [4.1]; body mass = 82.4 [4.6]) were randomly divided into 3 groups: morning PT (MPT), evening PT (EPT), and an active control group, each group consisting of 10 subjects. The players engaged in PT sessions twice weekly for a period of 6 weeks. The evaluation of biomotor abilities such as countermovement vertical jump, standing long jump, spike jump, block jump, 10-m sprint, T-test, sit and reach, and Y-balance test took place in the morning and evening before and after the intervention.

RESULTS

Both the MPT and EPT groups indicated significant (P < .05) improvements in all biomotor abilities from pretraining to posttraining during both the morning and evening testing sessions. Furthermore, the MPT group displayed greater adaptive responses in the vertical jump (P = .001), standing long jump (P = .023), and Y-balance test (P ≤ .01) compared to the EPT group. Time-of-day fluctuations were the same between the MPT and EPT groups at the pretest. Conversely, EPT demonstrated significantly more daytime variations than MPT in the jump, sprint, and balance tests at postintervention (P < .05).

CONCLUSION

Engaging in PT at specific times of the day has a significant impact on biomotor ability adaptations, with a focus on morning being more favorable than the evening for achieving greater gains in jump and balance performance of volleyball players.

Physiological and Performance Adaptations to Varying Rest Distributions During Short Sprint Interval Training Trials in Female Volleyball Players: A Comparative Analysis of Interindividual Variability

PURPOSE

This study aimed to examine the impact of different rest periods between short sprint interval training (SSIT) trials on the physiological and performance adaptations of female volleyball players.

METHODS

Twenty-four trained college athletes volunteered to participate in this study and were randomly assigned to 3 SSIT groups with different work-to-rest ratios (1:2 [5-s run:10-s rest], 1:4 [5-s run:20-s rest], and 1:6 [5-s work:30-s rest]). Before and after 6-week training, physiological parameters (maximum oxygen uptake, first and second ventilatory thresholds, and peak and mean power output) and physical performance measures (ie, countermovement vertical jump, 10-m sprint, and T-test change-of-direction speed) were evaluated.

RESULTS

After the training period, all groups improved (P = .001) their sport-related performance and physiological parameters, ranging from moderate to very large effect sizes. Comparative analysis of the magnitude of training effects indicated that the 1:6 SSIT group had in a significantly greater change in countermovement vertical jump (P = .007), 10-m sprint (P = .014), peak power output (P = .019), and mean power output (P = .05) compared with 1:2 SSIT group. By contrast, the 1:2 SSIT group demonstrated significantly (P = .022) greater changes in maximum oxygen uptake than the 1:6 SSIT group. However, the change-of-direction speed and changes in first and second ventilatory thresholds were the same among the groups (P > .05).

CONCLUSIONS

When performing SSIT, longer rest intervals are suitable for physical and anaerobic performance, and shorter rest periods are appropriate for enhancing the cardiorespiratory fitness of female volleyball players' performance.

How Do Age-Group Triathlon Coaches Manage Training Load? A Pilot Study

Multidisciplinary sports like triathlons require combining training for three different sports, and it is unclear how triathlon coaches manage this. During a 10-week period, we provided four age-group triathlon coaches with summary reports of the training completed by their athletes (n = 10) in the previous week. Coaches were then asked if the information provided to them was used to inform training prescription for the following week. The information provided to coaches included relative acute training load (rATL) and training stress scores (TSSs). Weekly fluctuations in rATL of >10% (spikes) were 83% (swim), 74% (bike) and 87% (run). Coaches adapted training loads for the upcoming week in 25% of all rATLs reported, and only 5% (swim), 33% (bike) and 9% (run) of the adjusted loads avoided spikes. Consequently, there were 22 single-discipline acute training load spikes vs. 14 spikes when combining all three disciplines. Only 1.5% of training was lost to injury, mostly after a large running-based training load spike (>30%). Coaches largely overlooked the information provided in the report when prescribing exercise for the following week, and when adjusted, it failed to bring weekly load variability <10%.

Optimal dose of vigorous physical activity on cardiorespiratory and perceptual response for sedentary youths using internal load monitoring

Introduction

Vigorous physical activity (VPA) has been demonstrated to enhance cardiorespiratory fitness (CRF) in sedentary college students more effectively than other PA. However, differences in training volume may affect this outcome. This study examines the physiological, psychological, and internal training load (ITL) characteristics of VPA with varying volumes in a single session.

Methods

Thirty sedentary college students were divided into three groups: high-intensity interval training (HIIT), sprint interval training (SIT), and threshold training (THR). PA process was monitored. The study measured various cardiorespiratory parameters, including heart rate (HR), respiratory waveform and amplitude, respiratory rate (RR), tidal volume (TV), minute ventilation volume (VE), fractional concentration of oxygen in end-tidal gas (O2%), fractional concentration of end-tidal carbon dioxide (CO2%), global oxygen consumption (VO2), carbon dioxide discharge (VCO2), and the amount of carbon dioxide in the air. The following physiological indicators were measured: carbon dioxide discharge (VCO2), Oxygen pulse (OP), and respiratory exchange ratio (RER). Additionally, subjective perception indicators were recorded, including the feeling scale (FS), rating of perceived exertion (RPE), and dual-mode model (DMM). The session-RPE (s-RPE) and Edward's TRIMP were used to measure ITL.

Results

There were no significant differences in HR across the three conditions. THR had the highest level of TV (p = 0.043), but RR was significantly lower than that of HIIT and SIT (p < 0.01). HIIT had the highest levels of VO2, VCO2, O2%, and OP (p < 0.05). RPE was higher in HIIT and SIT compared to THR (p < 0.01), but the difference in FS was not significant. The DMM time-domain trajectories were similar in HIIT and THR. The correlation between exercise intensity, RPE, and FS was highest in THR group (r = 0.453, r = -0.58, r = -0.885). ITL did not show a significant difference between three conditions, but TRIMP and s-RPE readings were opposite in magnitude.

Conclusion

This study proposes that using an appropriate amount of THR to foster interest and adaptive strength during the PA habit establishment period, incorporating HIIT to enhance exercise efficiency during the adaptation period, and implementing SIT to reduce the monotony may effectively enhance the cardiorespiratory fitness of sedentary college students and establish PA habit.

The Relationship between Training Load and Injury Risk in Basketball: A Systematic Review

The relationship between training load and injury risk in basketball is an important area in sports injury prevention and performance enhancement; however, there is limited conclusive evidence of their associations. The aim of this systematic review was to examine the evidence of the relationship between training load and injury risk in basketball, which is one of the most common sports worldwide. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search was conducted on the PubMed, SCOPUS, and Web of Science databases up until March 2024. The search aimed to identify studies that prospectively and/or retrospectively examined the relationship between training load and injury risk in basketball. Inclusion criteria were limited to studies published before February 2024. The quality of each study was assessed using the Newcastle-Ottawa Quality Assessment Scale and Oxford Centre for Evidence-Based Medicine levels of evidence. A narrative synthesis of the findings was performed. A total of 14 articles met the inclusion criteria and were included in the review. Of these, 11 studies reported at least partially statistically significant results, providing evidence of a relationship between training load and injury risk. In conclusion, the findings of this review suggest a clear relationship between training load and injury risk in basketball.

Sex differences in the adaptations in maximal strength and anaerobic power to upper body plyometric training

This study aimed to compare the effects of a 6-week upper body plyometric training (UBPT) on maximal strength and anaerobic power performance of male and female subjects. Forty collegiate physically active male and female subjects participated in the study and were assigned to either UBPT group (M-UBPT, n = 10, F-UBPT, n = 10) or control group (M-CON, n = 10; F-CON, n = 10). The training groups performed 6 weeks of progressive overload UBPT three times per week using six exercises and were evaluated for upper-body anaerobic power and maximal strength, 3-kg medicine ball throw (MBT), push-up endurance, and reaction time at pre- and post-intervention. After the training intervention, the M-CON and F-CON groups did not show significant (p > 0.05) changes in the variables, while both the M-UBPT and F-UBPT groups demonstrated significant (p = 0.001) medium to very large improvements in their performance as follows: maximal strength (effect size [ES] = 0.55, 0.92), MBT (ES = 1.96, 0.89) peak power output (ES = 2.31, 1.52), mean power output (ES = 2.19, 1.11), push-up endurance (ES = 1.26, 0.70), and reaction time (ES =  - 2.16, - 1.56), respectively. Nevertheless, the male group experienced more significant improvements in the MBT (p = 0.001), peak (p = 0.001) and mean power output (p = 0.01), as well as reaction time (p = 0.01) compared to the female group when utilizing UBPT. In conclusion, it is imperative to take sex into account as a crucial factor when incorporating UBPT, particularly if the objective is to enhance anaerobic power output, muscular power, and reaction time.

Exploring the role of mindfulness in the stress-recovery balance: 10-Day monitoring of young BMX riders in an intensive training center during a pre-competition cycle

Considering mindfulness as a multidimensional disposition domain-specific skill and state, this study aimed to explore the effect of the dimensions of mindfulness on the trajectories of biopsychosocial stress-recovery balance and on HRV over 10 days of a pre-competitive cycle. 24 young BMX riders completed mindfulness disposition and domain-specific skill scales. Monitoring of the recovery-stress states was based on biopsychosocial measurements (daily and biweekly). RMSSD was used to assess the organism ability to cope with the training program stimulus. After each training session, riders self-rated their state of mindfulness. Multilevel growth curve analyses examined the linear and/or quadratic trajectories of the athletes' recovery-stress states and the effect of mindfulness on these trajectories. Mindfulness states results showed that the refocusing state had a significant negative quadratic effect over time on daily recovery and sport-specific recovery, and the awareness state on general recovery and total recovery. Concerning the dispositions of mindfulness, the observing component had a significant positive quadratic effect over time on daily stress. Nonreactivity had a significant positive quadratic effect over time on daily recovery and sport-specific recovery, and a significant positive effect on RMSSD. Acting with awareness had a significant positive effect on daily recovery and a significant negative effect on RMSSD. The study offered a better understanding of the effect of mindfulness (dispositions, domain-specific skills, and states) and its different components on the stress-recovery balance. The results suggest that mindfulness could be considered a promising effective psychological recovery strategy.

Seasonal Muscular Power Changes: Considerations of Concurrent Resistance and Field-Based Training in Professional Rugby League

ABSTRACT

Redman, KJ, Wade, L, Whitley, R, Connick, MJ, Kelly, VG, and Beckman, EM. Seasonal muscular power changes: considerations of concurrent resistance and field-based training in professional rugby league. J Strength Cond Res 38(9): 1620-1626, 2024-A rugby league player's ability to develop or maintain lower-body power will be significantly influenced by the resistance and field-based training loads completed. This study aimed to examine the power changes across a rugby league season and to investigate the relationship of concurrent training and training experience on power changes. Eighteen rugby league players participated in this study. Lower-body power was evaluated using a countermovement jump throughout the season. Four measures of external training loads were collected. A Friedman's test was used to assess differences in power throughout different phases of the season. A series of Spearman's rank-order correlations were conducted to assess the relationship between percentage changes in power during the training block, external training loads, and training experience. Countermovement jump peak velocity significantly decreased from the start ( p = 0.006) and end of pre-season ( p = 0.022) to the late competition. Correlation analysis revealed a large significant association between early competition field-based external loads (relative ( rs = -0.571) and total distance ( rs = -0.628)) and change in peak power. Very large significant negative relationships were also observed between mid-competition volume load with change in peak force ( rs = -0.825) and peak power ( rs = -0.736). Training experience was not significantly associated with changes in muscular power variables throughout this study. Coaches should seek to monitor changes in peak power when competition begins and to assist with decision-making for potential adjustments to running volume and intensity during field-based sessions.

A Randomized Controlled Trial to Determine the Impact of Resistance Training versus Aerobic Training on the Management of FGF-21 and Related Physiological Variables in Obese Men with Type 2 Diabetes Mellitus

Fibroblast growth factor 21 (FGF-21) has been suggested as a potential therapeutic target for insulin resistance in health-related metabolic disorders such as type 2 diabetes. Despite the metabolic effects of resistance (RT) and aerobic training (AT) on diabetes symptoms, uncertainty exists regarding the superiority of effects manifested through these training approaches on FGF-21 and biochemical and physiological variables associated with metabolic disorders in men diagnosed with type 2 diabetes. This study aimed to investigate the impact of a 12-week RT and AT on FGF-21 levels and symptoms associated with metabolic disorders in male individuals diagnosed with type 2 diabetes. Thirty-six sedentary obese diabetic men (40 to 45 years old) were matched based on the level of FGF-1. They and were randomly divided into two training groups (RT, n = 12 and AT, n = 12) performing three days per week of moderate-intensity RT or AT for 12 weeks and an inactive control group (n = 12). Both training interventions significantly improved FGF-21, glucose metabolism, lipid profile, hormonal changes, strength, and aerobic capacity. Subgroup analysis revealed that RT had greater adaptive responses (p < 0.01) in fasting blood sugar (ES = -0.52), HOMA-IR (ES = -0.87), testosterone (ES = 0.52), cortisol (ES = -0.82), FGF-21 (ES = 0.61), and maximal strength (ES = 1.19) compared to AT. Conversely, AT showed greater changes (p < 0.01) in cholesterol (ES = -0.28), triglyceride (ES = -0.64), HDL (ES = 0.46), LDL (ES = -0.73), and aerobic capacity (ES = 1.18) compared to RT. Overall, both RT and AT interventions yielded significant moderate to large ES in FGF-21 levels and enhanced the management of biochemical variables. RT is an effective method for controlling FGF-21 levels and glucose balance, as well as for inducing hormonal changes. On the other hand, AT is more suitable for improving lipid profiles in overweight men with type 2 diabetes mellitus.

Analyzing activity and injury risk in elite curling athletes: seven workload monitoring metrics from session-RPE

Objective

The study aimed to compare the differences in the performance of seven session-rating of perceived exertion (RPE)-derived metrics (coupled and uncoupled acute: chronic workload ratio (ACWR), weekly ratio of workload change, monotony, standard deviation of weekly workload change, exponentially weighted moving average (EWMA), and robust exponential decreasing index (REDI)) in classifying the performance of an injury prediction model after taking into account the time series (no latency, 5-day latency, and 10-day latency).

Design

The study documented the RPE of eight curlers in their daily training routine for 211 days prior to the Olympic Games.

Methods

Seven Session-RPE (sRPE)-derived metrics were used to build models at three time series nodes using logistic regression and multilayer perceptron. Receiver operating characteristic plots were plotted to evaluate the model's performance.

Results

Among the seven sRPE-derived metrics multilayer perceptron models, the model without time delay (same-day load corresponding to same-day injury) exhibited the highest average classification performance (86.5%, AUC = 0.773). EMWA and REDI demonstrated the best classification performance (84.4%, p < 0.001). Notably, EMWA achieved the highest classifying accuracy in the no-delay time series (90.0%, AUC = 0.899), followed by the weekly load change rate under the 5-day delay time series (88.9%, AUC = 0.841).

Conclusion

EWMA without delay is a more sensitive indicator for detecting injury risk.

Quantifying internal and external training loads in collegiate male volleyball players during a competitive season

BACKGROUND

The long-term monitoring of internal and external training load is crucial for the training effectiveness of athletes. This study aims to quantify the internal and external training loads of collegiate male volleyball players during the competitive season. The internal and external training load variables were analyzed across mesocycles and playing positions.

METHODS

Fourteen participants with age of 20.2 ± 1.3 years, height of 1.81 ± 0.05 m, and body weight of 70.8 ± 5.9 kg were recruited. The data were collected over a 29-week period that was divided into four mesocycles: preparation 1 (P1, weeks 1-7), competition 1 (C1, weeks 8-14, including a 5-day tournament in week 14), preparation 2 (P2, weeks 15-23), and competition 2 (C2, weeks 24-29, including a 6-day tournament in week 29). Each participant wore an inertial measurement unit and reported the rating of perceived exertion in each training session. The internal training load variables included weekly session rating of perceived exertion, acute: chronic workload ratio, and training monotony and strain. The external training load variables included jump count and height and the percentage of jumps exceeding 80% of maximal height.

RESULTS

C2 had the highest average weekly internal training load (3022 ± 849 AU), whereas P2 had the highest average weekly acute: chronic workload ratio (1.46 ± 0.13 AU). The number of weekly jumps in C1 (466.0 ± 176.8) was significantly higher than in other mesocycles. Weekly jump height was significantly higher in C1, P2, and C2. Internal training load was positively correlated with jump count (ρ = 0.477, p < 0.001). Jump count was negatively correlated with jump height (ρ = -0.089, p = 0.006) and the percentage of jumps exceeding 80% of maximal height (ρ = -0.388, p < 0.001). The internal and external training load variables were similar among different playing positions.

CONCLUSION

The participants exhibited significantly higher internal training load in C2 and higher jump height after P1. A high jump count was associated with higher internal training load and lower jump height. Excessive jumps may result in fatigue and reduce height.

Haemoglobin mass responses and performance outcomes among high-performance swimmers following a 3-week live-high, train-high camp at 2320 m

AIM

Greater quantification and characterisation of training load (TL) throughout Live-high, train-high (LHTH) altitude (ALT) training is required to identify periodisation strategies that may lead to physiological and performance improvements in swimmers.

PURPOSE

This study aimed to examine the physiological responses and performance outcomes of 14 high-performance swimmers (FINA points: 836.0 ± 35.1) following 3 weeks of LHTH at 2320 m, while characterising the training load periodisation strategy adopted during the intervention.

METHODS

Haemoglobin (Hb) mass was measured pre-, 7 and 14 days post-ALT via CO rebreathing. Performance in each athlete's primary event at national standard meets were converted to FINA points and compared from pre-to-post-ALT. TL was quantified at sea level (SL) and ALT through session rating of perceived exertion (RPE), where duration of each session was multiplied by its RPE for each athlete, with all sessions totalled to give a weekly TL. Pre-to-post-ALT changes were evaluated using repeated-measures ANOVA.

RESULTS

Hb mass increased significantly from 798 ± 182 g pre-ALT to 828 ± 187 g at 7 days post (p = 0.013) and 833 ± 205 g 14 days post-ALT (p = 0.026). Weekly TL increased from SL (3179 ± 638 au) during week one (4797 ± 1349 au, p < 0.001) and week two (4373 ± 967 au, p < 0.001), but not week three (3511 ± 730 au, p = 0.149). No evidence of improved SL swimming performance was identified.

CONCLUSION

A periodisation strategy characterised by a sharp spike in TL followed by a slight de-load towards the end of a LHTH intervention led to improved physiological characteristics but no change in the competitive performance of high-performance swimmers.

Effects of Different Weekly Set Volumes on Strength and Perceptual Responses in Athletes

This study investigated the effects of different resistance training (RT) volumes quantified by weekly sets at high intensity (load and effort) on dynamic strength adaptations and psychophysiological responses in trained individuals. Twenty-four athletes were randomly allocated to three groups that performed three (3 S, n=8), six (6 S, n=8), and nine (9 S, n=8) weekly sets, respectively, three times a week on the barbell back squat and bench press during an 8-week period. While all groups showcased strength gains (p<0.05), post hoc comparisons revealed that 6 S and 9 S elicited greater strength adaptations than 3 S in barbell back squat (p=0.027 and p=0.004, respectively) and bench press (p=0.001 and p=0.044, respectively). There were no differences between 6 S and 9 S conditions for back squat (p=0.999) and bench press (p=0.378). Although a time effect was observed for Session-RPE (p=0.014) and Total Quality Recovery scale (p=0.020), psychophysiological responses were similar among groups. Our findings suggest that performing six and nine weekly sets at high intensities led to greater strength gains compared to three weekly sets in strength-trained individuals, despite similar psychophysiological responses.

Standing on the Shoulders of Giants: Essential Papers in Sports and Exercise Physiology

PURPOSE

The purpose of this survey was to create a list of essential historical and contemporary readings for undergraduate and graduate students in the field of exercise physiology.

METHODS

Fifty-two exercise physiologists/sport scientists served as referees, and each nominated ∼25 papers for inclusion in the list. In total, 396 papers were nominated by the referees. This list was then sent back to the referees, with the instructions to nominate the "100 essential papers in sports and exercise physiology."

RESULTS

The referees cast 4722 votes. The 100 papers with the highest number of votes received 51% (2406) of the total number of votes. A total of 37 papers in the list of "100 essential papers" were published >50 years ago, and 63 papers were published since 1973.

CONCLUSIONS

This list of essential studies will provide a perspective on contemporary studies, the "giant's shoulders" to enable young scholars to "see further" or to understand where they have "come from." This compilation is also meant to impress on students that, given the (lack of) technology available in the past, some of the early science required enormous intuitive leaps on the part of historical scientists.

Five Weeks of Sprint Interval Training Improve Muscle Glycolytic Content and Activity But Not Time to Task Failure in Severe-Intensity Exercise

PURPOSE

This study examined the impact of a 5-wk sprint interval training (SIT) intervention on time to task failure (TTF) during severe-intensity constant work rate (CWR) exercise, as well as in glycolytic enzymatic content and activity, and glycogen content.

METHODS

Fourteen active males were randomized into either a SIT group ( n = 8) composed of 15 SIT sessions over 5 wk, or a control group ( n = 6). At pretraining period, participants performed i) ramp incremental test to measure the cardiorespiratory function; ii) CWR cycling TTF at 150% of the power output (PO) at the respiratory compensation point (RCP-PO) with muscle biopsies at rest and immediately following task failure. After 5 wk, the same evaluations were repeated (i.e., exercise intensities matched to current training status), and an additional cycling CWR matched to pretraining 150% RCP-PO was performed only for TTF evaluation. The content and enzymatic activity of glycogen phosphorylase (GPhos), hexokinase (HK), phosphofructokinase (PFK), and lactate dehydrogenase (LDH), as well as the glycogen content, were analyzed. Content of monocarboxylate transporter isoform 4 (MCT4) and muscle buffering capacity were also measured.

RESULTS

Despite improvements in total work performed at CWR posttraining, no differences were observed for TTF. The GPhos, HK, PFK, and LDH content and activity, and glycogen content also improved after training only in the SIT group. Furthermore, the MCT4 concentrations and muscle buffering capacity were also improved only for the SIT group. However, no difference in glycogen depletion was observed between groups and time.

CONCLUSIONS

Five weeks of SIT improved the glycolytic pathway parameters and total work performed; however, glycogen depletion was not altered during CWR severe-intensity exercise, and TTF remained similar.

Sphingolipid and Trimethylamine-N-Oxide (TMAO) Levels in Women with Obesity after Combined Physical Training

Obesity causes metabolic changes, such as the development of cardiovascular diseases. Moreover, physical exercise promotes protection against these diseases. Thus, the objective of the present study was to evaluate whether combined physical training can improve the metabolic system of women with obesity, reducing plasma concentrations of trimethylamine N-oxide (TMAO) and sphingolipids, regardless of weight loss. Fourteen obese women (BMI 30-40 kg/m2), aged 20-40 years, sedentary, were submitted to 8 weeks of combined physical training (strength and aerobic exercises). The training was performed three times/week, 55 min/session, at 75-90% maximum heart rate. All participants were evaluated pre- and post-exercise intervention, and their body composition, plasma TMAO, creatinine, lipid profile, and sphingolipid concentrations were recorded. Maximum oxygen consumption (VO2max), Speed lactate threshold 1 (SpeedLT1), and Speed lactate threshold 2 (SpeedLT2) evaluated physical performance. Results: After combined exercise, it did not change body composition, but TMAO, total cholesterol, and sphingolipid concentrations significantly decreased (p < 0.05). There was an increase in physical performance by improving VO2max, SpeedLT1, and SpeedLT2 (p < 0.05). The combined physical exercise could induce cardiovascular risk protection by decreasing TMAO in obese women, parallel to physical performance improvement, independent of weight loss.

Menstrual cycle patterns and their relationship with measures of well-being and perceived performance metrics in competitive and recreational resistance-trained athletes

BACKGROUND

There is mixed evidence on how the menstrual cycle (MC) affects sports performance, with many studies showing variations in performance during different phases of the MC, while other evidence shows that the MC's effects on performance may be trivial. Therefore, this exploratory longitudinal monitoring study was designed to investigate MC characteristics and symptoms in a resistance-trained (RT) population to look for associations between measures of well-being and perceived performance metrics across the MC.

METHODS

RT females reported their workout habits, perceived performance metrics, and measures of well-being while tracking their MC with detailed methods via daily check-ins in an app.

RESULTS

Most MC characteristics and symptoms in the present RT population aligned with previous research on the general population. However, the frequency of irregular cycles was higher than in previous research on the general population. The amount of individual variation and within-subject cycle-to-cycle variation in MC characteristics and MC symptoms was also high. All measures of well-being were significantly associated with specific days of the MC, demonstrating a change in well-being based on the timing of the MC. Several perceived performance metrics were significantly associated with changes across the MC, while others were not.

CONCLUSIONS

Overall, with the current evidence as it stands, a highly individualized approach should be taken for any training or performance considerations surrounding the MC due to the high levels of individual variation.

Exploring the effect of the menstrual cycle or oral contraception on elite athletes' training responses when workload is not objectively quantifiable: the MILS approach and findings from female Olympians

Objectives

Develop the Markov Index Load State (MILS) model, based on hidden Markov chains, to assess athletes' workload responses and investigate the effects of menstrual cycle (MC)/oral contraception (OC), sex steroids hormones and wellness on elite athletes' training.

Methods

On a 7-month longitudinal follow-up, daily training (volume and perceived effort, n=2200) and wellness (reported sleep quality and quantity, fitness, mood, menstrual symptoms, n=2509) data were collected from 24 female rowers and skiers preparing for the Olympics. 51 MC and 54 OC full cycles relying on 214 salivary hormone samples were analysed. MC/OC cycles were normalised, converted in % from 0% (first bleeding/pill withdrawal day) to 100% (end).

Results

MILS identified three chronic workload response states: 'easy', 'moderate' and 'hard'. A cyclic training response linked to MC or OC (95% CI) was observed, primarily related to progesterone level (p=8.23e-03 and 5.72e-03 for the easy and hard state, respectively). MC athletes predominantly exhibited the 'easy' state during the cycle's first half (8%-53%), transitioning to the 'hard' state post-estimated ovulation (63%-96%). OC users had an increased 'hard' state (4%-32%) during pill withdrawal, transitioning to 'easy' (50%-60%) when on the pill. Wellness metrics influenced the training load response: better sleep quality (p=5.20e-04), mood (p=8.94e-06) and fitness (p=6.29e-03) increased the likelihood of the 'easy' state. Menstrual symptoms increased the 'hard' state probability (p=5.92e-02).

Conclusion

The MILS model, leveraging hidden Markov chains, effectively analyses cumulative training load responses. The model identified cyclic training responses linked to MC/OC in elite female athletes.

Relationship Between Training Load, Neuromuscular Fatigue, and Daily Well-Being in Elite Young Wrestlers

Purpose: This study investigated acute workload (wAW), chronic workload (wCW), acute: chronic workload ratio (wACWR), training monotony (wTM), perceived load training strain indicators (wTS), and countermove- ment jump (CMJ) as indicators of wellness in one season and defined weekly variations. In addition, we analyzed the relationships between training load measurements and weekly reports. Methods: 16 elite young wrestlers were monitored daily with individual observations for 46 consecutive weeks throughout the season. Training load was obtained using the session rating of perceived effort. wSleep, wStress, wFatigue & wMuscle Soreness well-being were monitored daily using the Hooper index. Results: As a result of the analysis, it was found that there is a moderate relationship (r = 0.51, p = .003) between ACWR and w mean load (A.U.) and a high relationship (r = 0.81, p < .001) between monotony and strain. Conclusion: All variables other than ACWR, w mean load, strain, and monotony presented small and statistically insignificant relationships. These results provide coaches and practitioners with new insights into perceived loads and health changes during a season at the elite youth level.

Scapula-Focused Exercises With or Without Biofeedback and Corticospinal Excitability in Recreational Overhead Athletes With Shoulder Impingement

CONTEXT

Individuals with shoulder impingement syndrome (SIS) exhibit changes in corticospinal excitability, scapular kinematics, and scapular muscle-activation patterns. To restore the scapular kinematics and muscle-activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular-orientation and strength training.

OBJECTIVE

To investigate whether scapular-orientation and strength training can reverse the altered corticospinal excitability of recreational overhead athletes with SIS.

DESIGN

Randomized controlled clinical trial.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty-one recreational overhead athletes with SIS: 20 in the scapular-orientation group (age = 26.45 ± 4.13 years, height = 171.85 ± 7.88 cm, mass = 66.70 ± 10.68 kg) and 21 in the strengthening group (age = 26.43 ± 5.55 years, height = 171.62 ± 5.87 cm, mass = 68.67 ± 10.18 kg).

INTERVENTION(S)

Both groups performed a 30-minute training protocol consisting of 3 exercises to strengthen the lower trapezius (LT) and serratus anterior muscles without overactivating the upper trapezius muscles. Participants in the scapular-orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not receive biofeedback or cues for scapular motion.

MAIN OUTCOME MEASURE(S)

Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured.

RESULTS

After training, both groups demonstrated an increase in motor-evoked potentials in the LT (P = .004) and increases in scapular upward rotation (P = .03), LT activation (P < .001), and serratus anterior activation (P < .001) during arm elevation. Moreover, the scapular-orientation group showed higher LT activation levels during arm elevation after training than the strengthening group (P = .03).

CONCLUSIONS

With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater LT activation, so feedback and cues are recommended during scapula-focused training.

Absence of Monotony and Strain Effects on Referees' Physical Performance During International Basketball Federation World Cup Basketball Competition

PURPOSE

The study aimed to conduct a comparative analysis of physical performance indicators and assess the levels of performance monotony and strain experienced by basketball referees.

METHODS

The study involved the participation of 12 basketball referees (mean age: 40.0 [4.9] y) affiliated with the International Basketball Federation. The investigation was carried out throughout 2 density tournaments, wherein the maximum heart rate, average heart rate, performance monotony, and performance strain were documented for 3 variables.

RESULTS

The findings indicated significant variations in the mean heart rate, maximum heart rate, total distance monotony, total distance strain, the total number of sprints monotony, the total number of sprints strain, calories monotony, and calories strain (P < .05). Decreasing the density of elite-level basketball competitions has been observed to reduce the monotony and strain experienced by referees. However, this action does not increase motion distance or speed zones.

CONCLUSIONS

The environmental stressors experienced by senior-level athletes (World Cup) differ from those encountered by younger athletes (World Cup Under 19). Further investigation is required to ascertain the potential effects of competition monotony and strain on decision-making processes and the overall quality of refereeing.

Machine learning models for assessing risk factors affecting health care costs: 12-month exercise-based cardiac rehabilitation

Introduction

Exercise-based cardiac rehabilitation (ECR) has proven to be effective and cost-effective dominant treatment option in health care. However, the contribution of well-known risk factors for prognosis of coronary artery disease (CAD) to predict health care costs is not well recognized. Since machine learning (ML) applications are rapidly giving new opportunities to assist health care professionals' work, we used selected ML tools to assess the predictive value of defined risk factors for health care costs during 12-month ECR in patients with CAD.

Methods

The data for analysis was available from a total of 71 patients referred to Oulu University Hospital, Finland, due to an acute coronary syndrome (ACS) event (75% men, age 61 ± 12 years, BMI 27 ± 4 kg/m2, ejection fraction 62 ± 8, 89% have beta-blocker medication). Risk factors were assessed at the hospital immediately after the cardiac event, and health care costs for all reasons were collected from patient registers over a year. ECR was programmed in accordance with international guidelines. Risk analysis algorithms (cross-decomposition algorithms) were employed to rank risk factors based on variances in their effects. Regression analysis was used to determine the accounting value of risk factors by entering first the risk factor with the highest degree of explanation into the model. After that, the next most potent risk factor explaining costs was added to the model one by one (13 forecast models in total).

Results

The ECR group used health care services during the year at an average of 1,624 ± 2,139€ per patient. Diabetes exhibited the strongest correlation with health care expenses (r = 0.406), accounting for 16% of the total costs (p < 0.001). When the next two ranked markers (body mass index; r = 0.171 and systolic blood pressure; r = - 0.162, respectively) were added to the model, the predictive value was 18% for the costs (p = 0.004). The depression scale had the weakest independent explanation rate of all 13 risk factors (explanation value 0.1%, r = 0.029, p = 0.811).

Discussion

Presence of diabetes is the primary reason forecasting health care costs in 12-month ECR intervention among ACS patients. The ML tools may help decision-making when planning the optimal allocation of health care resources.

Mind the Gap: Comparison of External Load and Load Variation Between a Reserve Team in a 1-Game Week Microcycle and Its First Team in a 2-Game Week Microcycle Within an Elite Professional Soccer Club

ABSTRACT

Carpels, T, Scobie, N, Macfarlane, NG, and Kemi, OJ. Mind the gap: comparison of external load and load variation between a reserve team in a 1-game week microcycle and its first team in a 2-game week microcycle within an elite professional soccer club. J Strength Cond Res 38(5): e235-e242, 2024-The aim of this study was to quantify and compare weekly external load and within-week load variation of reserve team players (RES) in a 1-game week microcycle to first team players (FT) in a 2-game week microcycle within the same professional soccer club. External load data were collected between 2017 and 2020 for the following parameters: duration, total distance (TD), total high-speed distance (THSD; >19.8 km·h -1 ), high-speed distance (HSD; 19.8-25.2 km·h -1 ), sprint distance (SD; >25.2 km·h -1 ), number of sprints (number of efforts >25.2 km·h -1 ), number of high-speed efforts (number of HS efforts >19.8 km·h -1 ), meters per minute (m·min -1 ), and high-speed meters per minute (HS m·min -1 ). First team players were subcategorized into starters (ST) and nonstarters (NST). Intergroup differences in cumulative weekly load and weekly load patterns were statistically analyzed, whereas training monotony (TM) was quantified to assess intragroup, within-week, load variation. Reserve team players showed similar weekly loads to ST, apart from significant differences ( p < 0.005) in duration (8%), TD (21%), and HS efforts (16%). Similar to ST, RES showed greater values than NST ( p < 0.0005) for duration (10%), TD (9%), THSD (30%), HSD (26%), SD (45%), sprints (40%), and HS efforts (22%). Weekly patterns in RES were different from ST and NST ( p < 0.05). Training monotony was highest for NST for all parameters, apart from the number of sprints. Reserve team players need to be prepared to cope with cumulative weekly loads and the lack of recovery between games that ST face. However, when RES become NST, effective loading strategies need to be designed within the limits of 2-game week microcycles to ensure continuous development.

Mass Participation and Tournament Event Management for the Team Physician: A Consensus Statement (2022 Update)

ABSTRACT

Mass participation events include endurance events (e.g., marathon, triathlon) and/or competitive tournaments (e.g., baseball, tennis, football (soccer) tournaments). Event management requires medical administrative and participant care planning. Medical management provides safety advice and care at the event that accounts for large numbers of participants, anticipated injury and illness, variable environment, repeated games or matches, and mixed age groups of varying athletic ability. This document does not pertain to the care of the spectator.

Mass Participation and Tournament Event Management for the Team Physician: A Consensus Statement (2022 Update)

ABSTRACT

Mass participation events include endurance events (e.g., marathon, triathlon) and/or competitive tournaments (e.g., baseball, tennis, football (soccer) tournaments). Event management requires medical administrative and participant care planning. Medical management provides safety advice and care at the event that accounts for large numbers of participants, anticipated injury and illness, variable environment, repeated games or matches, and mixed age groups of varying athletic ability. This document does not pertain to the care of the spectator.

Training Characteristics, Performance, and Body Composition of Three U23 Elite Female Triathletes throughout a Season

(1) Background: There is a lack of data on the long-term training characteristics and performance markers of elite young female endurance athletes. The aim of this study was to present the training load (ECOs), as well as the evolution of the anthropometric values and performance of three elite U23 female triathletes over a season. (2) Methods: General training data and performance data relating to the swimming, cycling, and running legs of the 2021 season were described. The training intensity distribution (TID) was presented using the triphasic model, while the training load was based on the ECO model. An anthropometric analysis was also conducted in accordance with the ISAK standards. (3) Results: Triathletes increased their VO2max in cycling (6.9-10%) and running (7.1-9.1%), as well as their power and speed associated with the VO2max (7.7-8.6% in cycling and 5.1-5.3% in running) and their swimming speed associated with the lactate thresholds (2.6-4.0% in LT2 and 1.2-2.5% in LT1). The triathletes completed more than 10 h of weekly average training time, with peak weeks exceeding 15 h. The average TID of the three triathletes was 82% in phase 1, 6% in phase 2, and 12% in phase 3. A decrease in the sum of skinfolds and fat mass percentage was observed during the season in the three triathletes, although the last measurement revealed a stagnation or slight rise in these parameters. (4) Conclusions: The triathletes performed a combination of two training periodization models (traditional and block periodization) with a polarized TID in most of the weeks of the season. Improvements in performance and physiological parameters were observed after the general preparatory period as well as a positive body composition evolution throughout the season, except at the end, where the last measurement revealed stagnation or a slight decline. This study can be useful as a general guide for endurance coaches to organize a training season with female U23 triathletes.

Recovery in elite youth basketball players: The responsiveness of the psychophysiological measurements and the role of testosterone concentration

This study investigated the recovery responses to the Total Quality Recovery (TQR), Well-Being questionnaire (WBQ), and Heart Rate (HR) responses to Submaximal Running Test (SRT), and the influence of salivary testosterone concentration (TEST) on these responses in 25 elite youth (U15) male basketball players. TQR, WBQ, and HR measurements were assessed after 48 hours of rest (T1), 24 hours after the 1st day of training (T2) and 24 hours after the 2nd day of training (T3). Salivary sampling was conducted at T1 and T3. A significant decrease was observed for TQR (F = 4.06; p = 0.01) and for WBQ (F = 5.37; p = 0.008) from T1 to T3. No difference among the three-time points was observed for HR and HR Recovery, and the TEST concentration did not influence the results. These results show that TQR and WBQ are sensitive to acute transient alterations in training loads (TL) and may be utilized to monitor recovery in elite youth basketball players. The HR related measurements presented limited responsiveness, and the TEST seems not to influence the recovery of these players who are competing at highest performance level.

Weekly Fluctuations in, and Associations Between, Salivary Hormone Responses, Load, and Well-Being During the Pre-season in Professional Male Basketball Players

ABSTRACT

Kamarauskas, P, Scanlan, A, Ferioli, D, and Conte, D. Weekly fluctuations in, and associations between, salivary hormone responses, load, and well-being during the pre-season in professional male basketball players. J Strength Cond Res 38(1): 128-135, 2024-This study aimed to (a) quantify weekly fluctuations in hormonal responses (testosterone [T], cortisol [C], and their ratio [T:C]), external (PlayerLoad [PL] and PL·minute-1) and internal (session rating of perceived exertion load [sRPE-load], summated heart rate zones [SHRZs], and percentage of maximal heart rate [%HRmax]) load measures, and well-being measured using a self-reported questionnaire and (b) determine the associations between weekly changes in hormonal responses and load measures with weekly changes in well-being during the pre-season phase in basketball players. Twenty-one professional male basketball players (age: 26.2 ± 4.9 years) were monitored during a 5-week pre-season phase. Linear mixed models were used to determine weekly differences in each variable and associations between weekly changes in hormonal and load variables with weekly changes in well-being. Findings revealed that T (p < 0.001) and T:C (p = 0.002) increased toward the end of the pre-season phase. Moreover, higher (p < 0.05) external (PL·minute-1) and internal (%HRmax) load intensities were evident during the first 3 weeks of the pre-season, with no significant fluctuations in other load variables. Weekly changes in PL and sRPE-load were negatively associated (p < 0.05) with weekly changes in well-being, albeit weak in magnitudes (R2 = 0.061-0.105). These results highlight that a periodized approach was undertaken across the pre-season predominantly predicated on altering weekly load intensities, which coincided with positive hormonal responses toward the end of the pre-season. In addition, weak relationships were evident between weekly changes in hormonal responses and load measures with well-being, emphasizing that a low commonality may be present between these constructs.

Combined Endurance and Strength or Only Endurance Training? Effects of Training Mode on Neuromuscular Characteristics and Functional Abilities in Obese Adolescent Girls Enrolled in a Weight-Reduction Program

The aim of the present study was to examine whether combining strength and endurance training would promote better improvements in neuromuscular characteristics and functional abilities than endurance training alone in obese adolescent girls enrolled in a weight-reduction program. Twenty-four obese adolescent girls (12-15 years) volunteered to participate in a 9-month training program. Participants were allocated into two groups following either (i) combined training (endurance + strength; E+ST) or (ii) endurance training (ET) program. Absolute and specific maximal torque, muscle size, and maximal voluntary activation level (VA) of the knee extensor (KE) and plantar flexor (PF) muscles were assessed. Moreover, functional abilities such as balance and fatigability during a maximal isometric intermittent contraction test of the KE muscles were measured before and after the intervention. The force of the adductor pollicis (AP) muscles was used as a control to account for any effect of growth or mechanical unloading on neuromuscular properties and muscle size. While absolute and specific torque of the KE (+14.7 ± 12.1% and +14.4 ± 15.5%; p < 0.05) and PF (+19.2 ± 16.7% and +18.3 ± 17.5%; p < 0.001) muscles increased in the E+ST group, PF torque decreased, and KE torque did not change in the ET group (-22.6 ± 10.5% and -15.0 ± 17.2%; p < 0.001). Moreover, the VA of the KE muscles increased for the E+ST (+6.1 ± 5.6%; p < 0.01) group and decreased for the ET group (-5.4 ± 5.4%; p < 0.05). In contrast, VA remained similar in the PF muscles for both groups. The number of repetitions during the fatigability test increased in the ET group (38.4 ± 22.3 vs. 84.1 ± 33.3; p = 0.032) and was unchanged in the E+ST group (50.8 ± 14.1 vs. 54.2 ± 37.8), but it was associated with a higher force level. Moreover, balance improved in the E+ST group, but not in the ET group. To conclude, physical training combining strength and endurance training promoted larger improvement in neuromuscular characteristics and functional abilities than endurance training alone in obese adolescent girls. Greater neuromuscular adaptations resulting from the E+ST training may be beneficial for preserving or even increasing functional abilities and possibly induce greater engagement in the active lifestyle of obese adolescents. However, the endurance component seems necessary in training programs to reduce fatigability during daily living activities.

Monitoring load, wellness, and psychological variables in female and male youth national team football players during international and domestic playing periods

Aim

To study differences in total load exposure, wellness, and psychological variables in youth female (N = 19) and male (N = 20) national team football players during domestic and international playing periods, respectively.

Procedures

The players filled out questionnaires on well-being, stress, and resilience before and after both playing periods lasting 8 days each. The Hooper index was used to monitor daily wellness levels during both playing periods. The number of training sessions and matches were recorded, and the session rating of perceived exertion was collected. Training load, monotony, and strain were calculated. Daily measurements were used to evaluate in-period changes, and composite scores were used to describe differences between periods.

Results

The international compared to the domestic playing period was for both groups characterized by more matches played, longer field training session durations, and of fewer gym-based sessions (P < 0.05). The male players increased total exposure time (25%; P < 0.05), monotony (P < 0.001), and strain (P < 0.001), which was not changed in the female players. Well-being decreased (P < 0.05) during the international playing period in male players. Stress levels were higher (P < 0.05) for both genders during the international compared to the domestic playing period. During the international playing period, positive correlations were found between the initial levels of stress, and the change in stress (P = 0.03; r2 = 0.12), and between the changes in total load and changes in well-being (P = 0.02; r2 = 0.12), whereas a negative correlation was found between the changes in wellness and stress (P = 0.03; r2 = 0.14).

Conclusion

A playing period characterized by increased match focus, longer field training sessions, and fewer gym-based training activities may lead to changes in the physical and mental profiles of youth national team football players. Alterations to load exposure and wellness may influence mental health. Players with high initial stress levels may be subjected to greater changes compared to other players. Sports scientists and medical staff may benefit from initiating structured monitoring systems to track alterations in physical load and mental health in youth national team players.

Muscular Adaptations and Psychophysiological Responses in Resistance Training Systems

Purpose: We investigated the effect of drop-set (DS) and rest-pause (RP) systems compared to traditional (TRAD) resistance training on muscular adaptations and psychophysiological responses. Methods: Twenty-seven trained men (age: 23.4 ± 3.4 years; resistance training experience: 5.1 ± 1.7 years) were assigned to experimental groups (DS: n = 9, 3 × 10 repetitions at 75% with 6 additional repetitions at 55% 1RM; RP: n = 9, 3 × 16 repetitions at 75% 1RM; TRAD: n = 9, 4 × 12 repetitions at 70% 1RM) and performed lower-limb training sessions twice a week for 8 weeks. Maximum dynamic strength (1RM) and localized muscular endurance (LME) tests were performed in 45° leg press at baseline and post intervention. Session-RPE was assessed 15 min after the end of each training session. Results: A significant time vs. group interaction was observed for 1RM (p = .012) and LME (p < .0001). Post hoc comparisons revealed that RP elicited greater gains in muscular strength than DS (p = .044) but not TRAD (p = .116); and DS elicited greater LME than RP (p < .001) and TRAD (p = .001). No statistical differences were observed in Session-RPE and training strain between conditions; however, RP promoted higher training monotony (p = .036) than DS and TRAD. Conclusions: The DS and RP systems have a potential role in training programs aiming to promote muscle strength and localized muscular endurance adaptations, respectively. However, RP may promote higher training monotony than DS and TRAD, even though the other psychophysiological responses are similar.