Medicine & Science in Sports & Exercise

Repeated high-intensity running (RHIR) exercise is known to affect central and peripheral functioning. Declines in RHIR performance are exacerbated by environmental heat stress. Accordingly, the use of post-exercise cooling strategies (COOL) is recommended as it may assist recovery. The present study aimed to investigate, in a hot environment (> 30{o}C), the effects of local COOL following RHIR on indices of soccer kicking movement and performance in youth soccer. Fifteen academy under-17 players (16.27 {+/-} 0.86 years-old; all post-PHV), acting as their own controls, participated. In #Experiment 1, players completed an all-out RHIR protocol (10 x 30 m bouts interspersed with 30 s intervals). In #Experiment 2, the same players performed the same running protocol under two conditions, 1) 5 minutes of COOL where ice packs were applied to the quadriceps and hamstrings regions and, 2) a control condition involving only passive resting. In both experiments, perceptual measures [ratings of perceived exertion (RPE), pain and recovery], thigh temperature and kick-derived video kinematics (hip, knee, ankle and foot) and performance (ball speed and placement) were collected at baseline and post exercise and intervention. In the first experiment, RHIR led to moderate-to-large increases (p < 0.03) in RPE (d = 4.08), ankle eversion/inversion angle (d = 0.78) and mean radial error (d = 1.50) and small-to-large decreases (p < 0.04) in recovery (d = -1.83) and average/peak ball speeds (d = -0.42--0.36). In the second experiment RPE (p < 0.01; Kendalls W = 0.30) and mean radial error (p = 0.057; {eta}2 = 0.234) increased only post-control. Significant small declines in ball speed were also observed only post-control (p < 0.05; d = 0.35). Post-intervention CMfoot velocity was moderately faster in COOL as compared to control (p = 0.04; d = 0.60). RHIR acutely impaired kicking movement, ball speed and placement in youth soccer players. However, a short period of local cryotherapy may be beneficial in counteracting declines in indices of kicking performance in hot environment. Trial registration number#RBR-8prx2m - ReBEC Brazilian Clinical Trials Registry

Ultra-endurance places considerable physiological stress on the body, and understanding how hormonal fluctuations affect women, who take part in ultra endurance training and events, could improve both safety and performance. The aim of this pilot study was to explore physiological and perceptual responses across MC phases in trained female ultra-endurance athletes. MethodsNaturally menstruating participants (VO2max: 51.4 {+/-} 5.7 mL{middle dot}kg-{superscript 1}{middle dot}min-{superscript 1}; ultramarathon experience: 2.6 {+/-} 1.1 years) were recruited. Seven completed a questionnaire on past experiences and performance perceptions related to the MC. Six underwent physiological testing in the early follicular (EFP), late follicular (LFP), and mid-luteal (MLP) phases. Assessments included resting metabolic rate (RMR), heart rate variability (HRV), and an incremental treadmill test for submaximal and maximal performance. Phase-specific questionnaires recorded perceived performance and well-being. ResultsMore than half of participants (57.1%) reported perceived performance decrements in the days preceding and during menstruation. However, no significant differences were found in submaximal (heart rate, running economy, rate of perceived exertion) or maximal (VO2max, peak velocity, time to exhaustion) physiological markers across MC phases. Respiratory frequency at LT1 showed a significant main effect of phase (p = 0.045), though pairwise comparisons did not reach significance. Resting variables, including HRV and RMR, or well-being markers, did not vary significantly between phases. ConclusionsPhysiological performance remained stable across MC phases, though trends suggested improved ventilatory efficiency in the LFP compared to the MLP during submaximal work. Despite the small sample size, the frequent reporting of MC-related symptoms indicates the importance of personalised MC monitoring. These findings highlight the practicability of integrating both objective and perceptual measurements in ultra-endurance research and support further investigation with larger cohorts.

IntroductionDynamic knee valgus is linked to reduced hip abduction strength, a critical factor in knee stability during unilateral movements. While interventions to reduce dynamic knee valgus often use traditional hip abduction training, many neglect the eccentric function of hip abductors, essential for controlling femoral medial translation. This pilot study compared the effects of a four-week-long eccentric vs. concentric hip abduction training on hip abduction torque, countermovement jump performance, dynamic knee valgus measured during one-legged jumping and drop landing, and determined if reductions in dynamic knee valgus correlated with increases in hip abduction torque and countermovement jump performance. Materials and MethodsAsymptomatic, physically active female college students (n = 20, 21.3 {+/-} 2.51 years) with dynamic knee valgus were randomized to either eccentric or concentric hip abduction strength training. Testing included maximum hip abduction torque on an isokinetic dynamometer, single-leg countermovement jumps, and single-leg drop landings analyzed with 3D motion tracking. Participants trained three times per week for four weeks, performing four sets of 10 maximal effort repetitions. ResultsThe two groups did not differ at baseline in any outcomes (all p > 0.05). Eccentric hip abduction torque improved over time (F = 39.7, p < 0.001) without a group-by-time interaction. dynamic knee valgus decreased during single-leg countermovement jumps (time main effect: F = 33.5, p < 0.05) and single-leg drop landings (time main effect: F = 14.8, p < 0.05). The reductions in dynamic knee valgus, measured during single-leg countermovement jumps, were greater (p < 0.05) after eccentric vs. concentric training (group by time interaction: F = 5.57, p < 0.05). countermovement jump improved similarly in the two groups (time main effect: F = 5.1, p < 0.05), without group by time interaction. Improvements in hip abduction maximal torque and countermovement jump performance, and changes in dynamic knee valgus outcomes did not correlate (p > 0.05). ConclusionsHigh-intensity eccentric hip abductor strength training was superior in dynamic knee valgus improvement measured during single-leg countermovement jump but not during drop landings in asymptomatic young women.

ContextAlthough considerable cross-sectional evidence exists regarding the association between sport specialization and injury, sport-specific, prospective research is lacking. Similarly, sport specialization is associated with impairments in sleep and subjective well-being in youth athletes, but it is unknown whether this increases the risk of illness. ObjectiveTo determine the relationship between sport specialization status and in-season injury and illness risk in elite female adolescent soccer players. DesignProspective Cohort Study SettingPre-season evaluation of maximal aerobic capacity (VO2max) and sport specialization, and in-season self-reporting of daily training load (session-rating of perceived exertion), injury and illness resulting in lost sport participation time. Participants80 female youth soccer players (ages 13-18) from a local youth soccer organization. Main outcome measuresSport specialization status, injury and illness incidence during two 4-month competitive soccer seasons. Athletes were considered specialized if they participated in soccer exclusively versus multiple sports during the year. Mixed effects logistic regression models were used to individual injury and illness (yes/no) during the study period, using sport specialization, age, and training load as fixed effects and individual athlete as a random effect. ResultsSpecialized (n=46) athletes did not differ from non-specialized (n=34) athletes with respect to age, preseason physical activity, VO2max or in-season training load (all p>0.05). No difference was seen in the proportion of individuals from each group that reported an in-season injury (specialized = 19% v 17%, p=0.83) or illness (40% v 38%, p=0.82). After adjusting for age and training load, the individual injuries (OR= 0.86 [0.26, 2.8], p=0.81) and illnesses were not significantly predicted by specialization (OR= 1.06 [0.45, 2.5], p=0.89). ConclusionsAfter adjusting for age and training load, sport specialization status was not associated with in-season injury or illness risk in elite female soccer players. Key pointsO_LIPrior research regarding the associations between sport specialization and health outcomes has been primarily cross-sectional and failed to account for the confounding role of training load. C_LIO_LIAmong elite adolescent female soccer players with similar pre-season physical activity levels in-season training loads, sport specialization was not associated with injury or illness incidence across two competitive seasons. C_LI

It is unclear whether muscle functional adaptations to concentric (CON-RT) and eccentric (ECC-RT) resistance training are most specific to their exercise characteristics or the structural adaptations they evoke. In this study, the effects of effort- and volume-matched CON-RT and ECC-RT on regional hypertrophy, muscle architecture, and function were compared, and associations between the outcomes were explored. Twelve trained young men (25.5{+/-}3.6y) completed 18 isokinetic ankle-dorsiflexion exercise sessions over 6 weeks: CON-RT in one leg and ECC-RT in the other (2-4 sets, 6-10 maximal repetitions, 10{degrees}/s). Tibialis anterior size and architecture (ultrasound imaging) and maximum voluntary dorsiflexion function (isokinetic dynamometry) were assessed. Muscle thickness increased similarly between conditions and across proximal-distal regions (8%), pennation angle increased more in CON-RT (8%) than ECC-RT (4%), and fascicle length increased only after ECC-RT (7%). Functional adaptations were more closely associated with specific structural adaptations than with contraction mode, velocity, or angle. Isometric torque increased similarly in both conditions overall (8%) but CON-RT improved only at shorter muscle lengths and shifted the peak-torque angle leftward, whereas ECC-RT improved at both shorter and longer lengths and broadened the torque-angle plateau, which was associated with fascicle length increases. ECC-RT produced greater increases in both eccentric (13%) and concentric torques (17%) than CON-RT (3%, 9%, respectively), and changes were similar across velocities - contrary to the training specificity theory. Changes in pennation angle were associated with dynamic strength changes. These findings suggest that muscle function adapts to the structural changes induced by training, regardless of the training scheme used.

ObjectivesThis study will aim to assess the acute cardiopulmonary differences of a treadmill walking warm{square}up (WW) versus a suspension warm{square}up (SW) immediately preceding cardiopulmonary exercise testing (CPET) in recreationally active college{square}aged adults. The primary outcomes will be to assess differences in peak oxygen consumption, peak heart rate, and peak minute ventilation during CPET following a WW versus a SW. Secondary outcomes will include time to exhaustion, rate of perceived exertion, blood pressure, tidal volume, fraction of expired oxygen consumption, and respiration rate. MethodsThis study will be a randomized counterbalanced crossover design. Participants will complete two separate CPETs over two non{square}consecutive test days ([&ge;]48{square}h, [&le;]7{square}d). During each visit, participants will complete either a WW (6{square}min at self{square}selected pace on a treadmill, 0% grade) or SW (6{square}min dynamic sequence of suspension training exercises), followed by an incremental treadmill CPET protocol up to maximal exertion. Gas exchange, heart rate, blood pressure, and rate of perceived exertion will be measured at rest, after warm-up, during CPET protocol, immediately after, and after 5 minutes of resting. Analyses will use linear mixed-effects models and two one-sided tests for equivalence. ConclusionsThis protocol will determine whether a brief, dynamic suspension training warm{square}up is a practical and transferable approach or rather different from a traditional treadmill warm-up before CPET in active young adults. Ethics/registrationIRB SP2553 (June 25, 2025), clinical trials Identifier: NCT07215052.

ObjectivesRelative Energy Deficiency in Sport (REDs) is a syndrome driven by problematic low energy availability, impairing physiological and/or psychological function. While REDs assessment typically utilizes dual energy X-ray absorptiometry (DXA) of areal bone mineral density (BMD), high-resolution peripheral quantitative computed tomography (HR-pQCT) offers additional insight into bone microarchitecture, geometry, and volumetric BMD. This study aimed to evaluate bone health among female runners at risk for REDs using DXA and HR-pQCT measures. MethodsFemale runners aged 18-30 years, training at least 5 hours/week, were recruited and underwent anthropometric measurements, VO2 max testing, clinical laboratories, DXA scans, and HR-pQCT imaging of the tibia. REDs risk was assessed using validated questionnaires, clinical laboratories, and physician interviews. Participants were categorized as no-risk (green) or at-risk (yellow/orange/red) for REDs. ResultsTwenty-one participants (age 26 {+/-} 3 years) completed the study. Six were classified as no-risk and fifteen as at-risk for REDs. Sub-clinically low BMD (z-score [&le;]-1) was the most prevalent indicator in at-risk participants. The at-risk group reported significantly higher weekly mileage (>40 miles/week: 66.7% vs 33.3%, p=0.043) and lower maximum extensor strength on muscular endurance testing (p=0.015). While no other between-group differences reached statistical significance, 12 of 14 HR-pQCT values showed poorer outcomes in the at-risk group. ConclusionsDespite the small sample size, this pilot revealed consistent HR-pQCT trends suggesting potential links between REDs risk and compromised bone geometry, microarchitecture, and volumetric BMD. Integration of HR-pQCT with REDs screening may provide a more comprehensive characterization of bone health compared to DXA alone. SUMMARY BOXO_ST_ABSWhat is already known on this topicC_ST_ABSRelative Energy Deficiency in Sport (REDs) is a clinical syndrome driven by problematic low energy availability that negatively impacts bone density and increases risk for bone stress injury (BSI). What this study addsConsistent trends in HR-pQCT outcomes demonstrate possible patterns of compromised bone geometry, microarchitecture, and volumetric bone mineral density in athletes with elevated REDs risk. How this study might affect research, practice or policyOur findings suggest that integrating HR-pQCT imaging with REDs screening may provide a more comprehensive characterization of REDs-related bone health than DXA alone. Further research examining the relationship between REDs risk and detailed bone health measures, including geometry and microarchitecture, is warranted to better inform clinical practice and screening tools.

The optimal intra-set rest in cluster sets (CLS) plyometric-jump training (PJT) to improve physical fitness remains unclear. Thus, this study compared the effects of PJT with traditional (TRS) vs. CLS structures using different intra-set rests on physical fitness components. Forty- seven recreationally active young men performed 3-5 sets of 10-12 repetitions of upper- and lower-body exercises twice a week for six weeks using different set configurations as the TRS group (no intra-set rest), and the CLS10, CLS20 and CLS30 groups with 10, 20 and 30 s intra-set rest, respectively, while the total rest period (i.e., 180 s) was equated. Testing was carried out 48 h before and after the intervention and the rating of fatigue (ROF) was also assessed 20 min after the first and last session. There was no significant difference in the mean energy intake between groups (p > 0.05). The ANCOVA revealed that all groups showed similar improvements (p < 0.05) in body mass, body mass index, fat-free mass, one repetition maximum (dynamic strength) and repetitions to failure (muscular endurance) in back squat and chest press, handgrip strength, standing long jump, 20 m sprint, and 9-m shuttle run (change of direction speed), whereas the ROF decreases were greater in the CLS20 and CLS30 groups (p < 0.05). Compared to the TRS structure, six weeks of PJT with an intra-set rest of 20 s, or 30 s induced similar improvements in the measures of physical fitness and anthropometrics, with lower exercise-induced fatigue perception.

BackgroundContemporary sports nutrition guidelines recognize that endurance athletes should periodize their daily carbohydrate (CHO) intake according to the demands of their training and competitive schedule. However, objective assessments of the dietary CHO periodization practices adopted by endurance athletes during prolonged training periods are not readily available. ObjectivesTo objectively assess the magnitude of the CHO periodization practices adopted by endurance athletes via the formulation of a novel CHO Periodization Index (CPI). The CPI is proposed to represent a single metric to quantify how tightly an athletes CHO intake is matched with training load, the magnitude of adjustment, and how frequently these adjustments occur. MethodsSelf-selected training and dietary intake was reported daily by 55 endurance athletes (61.8% male) for 12 weeks (representing a total of 4,395 days of dietary assessments). Calculations were made for correlations between daily CHO intake and training load (product of session rating of perceived exertion and duration), CHO monotony (mean daily CHO intake divided by SD), CHO range (highest minus lowest single-day intake), and the CPI (correlation * range / monotony). Sub-group analysis was also performed to examine differences in CPI, frequency of fasted training sessions, and weekly training volume based on competitive level, habitual diet, and sex. ResultsMean participant daily CHO intake was 3.9 {+/-} 1.5 (range 1.2 to 7.2) g/kg, with the highest single-day intake being 17.6 g/kg. Mean CHO range was 6.6 {+/-} 3.1 (range 2.0 to 15.2) g/kg. Carbohydrate monotony values ranged from 1.0 to 6.0. Pearson correlations between training load and daily CHO intake ranged from -0.34 to 0.87. Mean CPI was 1.0 {+/-} 1.2 (range - 1.2 to 5.6) and was higher among the highest-level athletes. ConclusionEndurance athletes do not readily adjust daily CHO intake according to the demands of training. Furthermore, the CPI represents a promising tool that that can be used by researchers, coaches, and athletes to quantify CHO periodization practices and compare within and between individuals. Key PointsO_LIIt is recommended that endurance athletes adjust their daily carbohydrate intake according to variations in exercise volume and intensity, but there is limited knowledge of how this is being applied by athletes, and limited methods for quantifying or assessing the variations in intake. C_LIO_LIWe introduce a novel Carbohydrate Periodization Index (CPI), a single metric to capture how tightly an athletes carbohydrate intake is adjusted based on training load, the magnitude of adjustment, and how frequently these adjustments occur. C_LIO_LIData demonstrate that many endurance athletes do not follow recommended practices of adjustment in daily carbohydrate intake, or if they do, the magnitude of adjustment is small relative to changes in training volume and/or intensity. C_LI

BackgroundMeteorological factors such as barometric pressure, humidity, and temperature have been linked to weather-related symptoms in the general population, yet little is known about their influence on athletes daily well-being and performance. Individual variability in weather sensitivity has been reported in biometeorology research, suggesting that only certain individuals exhibit pronounced physiological responses to environmental fluctuations. However, no studies have examined within-person associations between multiple meteorological factors and daily condition or performance in competitive athletes. MethodsCollegiate baseball players were monitored over 10 randomly selected days during July-August 2025. Subjective condition and performance were assessed daily using a 3-point Likert scale (1 = poor, 2 = normal, 3 = good). Barometric pressure, humidity, and temperature were recorded hourly and summarized for each day using mean values, day-to-day changes, daily ranges, and rapid fluctuation indices. For each player, multivariable linear regression models were constructed to examine within-person associations between the three meteorological variables and daily condition or performance. Model fit (R2), regression coefficients ({beta}), and dominant meteorological factors were extracted. ResultsEighty players were included in the condition model and eighty-six in the performance model. High weather sensitivity (R2 [&ge;] 0.60) was observed in 22.5% of players for condition and 14.0% for performance, whereas low sensitivity (R2 [&le;] 0.20) was found in 26.3% and 16.3%, respectively. Temperature was the dominant explanatory factor in more than 80% of players, although subsets showed dominance of barometric pressure or humidity. Directionality varied across individuals: decreases in barometric pressure were associated with worsening conditions in 62.5% of players but improvement in 37.5%; similar bidirectional patterns were observed for humidity and temperature. ConclusionDaily meteorological fluctuations explain a meaningful proportion of within-person variation in condition and performance for a subset of collegiate baseball players. The substantial individual variability and diverse directional responses highlight weather sensitivity as a personalized characteristic rather than a uniform effect. These findings suggest that meteorological factors may represent a relevant contextual variable for daily readiness monitoring in susceptible athletes.

Objectivei) determine whether the grade of hamstring strain confirmed by magnetic resonance imaging (MRI) is related to time to return to play, and ii) describe the incidence, prevalence and grade of hamstring strains confirmed by MRI in elite Australian cricket players. DesignRetrospective case series. MethodsHamstring strains from professional domestic and international cricket teams over 13.5 seasons which had received MRI scans were graded using British Athletics Muscle Injury Classification (BAMIC) system. The main outcome measure was time to return to play. Results141 hamstring strain injuries with available MRI imaging scans were recorded during the study period (average 3.2 per 100 players per season: male 4.5, female 1.2). The most commonly injured muscle was biceps femoris (64%, 95% CI 56-71%) and the most frequent category of injury was grade 2C (27%, 20-35%). Across all injury grades, players were unavailable for full participation for a median of 23 (IQR 15-38) days and missed 3 (1-6) matches. The number of days unavailable were higher for injuries which were graded 2 or 3, compared to grade 1 (p=0.018, p=0.002 respectively), and injuries which included the tendon compared to those which did not (p=0.002). ConclusionsThis study provides evidence that higher grade injuries and those involving the intramuscular tendon are associated with a more prolonged return to play. This finding should be viewed in context of the study limitation that clinicians treating players were not blinded to the MRI findings.

BackgroundInter-set rest intervals (ISR) influence resistance training adaptations. Shorter intervals (<60s) promote metabolic stress, while longer intervals (>60s) are thought to enhance recovery, mechanical tension, and strength. AimThe systematic review and meta-analysis examined the effects of <60s vs. >60s ISR on hypertrophy, strength, and secondary outcomes in resistance-trained males. MethodsSix studies met the inclusion criteria, evaluating muscle hypertrophy, strength, metabolic hormones, power output, and motor unit recruitment. Standardised mean differences (SMDs) with 95% confidence intervals (CIs) were calculated, and forest plots were generated to visualise pooled effects. ResultsStrength was modestly improved with longer ISRs (SMD = -0.74) but only trivial differences in hypertrophy (SMD = 0.08). Metabolic hormone responses showed negligible variation between conditions (SMD = 0.11). Secondary outcomes were mixed, with motor unit recruitment slightly favouring shorter ISRs (SMD = -0.66), while power output tended to favour longer ISRs (SMD = -0.64). Forest plots illustrated the heterogeneity of effects across studies. ConclusionShorter ISRs appear to slightly reduce strength and power outcomes, while longer ISRs offer minimal benefit for hypertrophy. These findings suggest that longer ISRs may not confer superior benefits for muscle growth, as previously assumed in the literature (e.g., Schoenfeld, 2016). The variability across outcomes underscores the need for further research to refine ISR recommendations, particularly in trained individuals. What is already known on this topicO_LIInter-set rest intervals (ISR) influence hypertrophy and strength outcomes in resistance training. C_LIO_LIShort rest (<60 s) increases metabolic stress but may impair recovery and force output. C_LIO_LILonger rest (>60 s) consistently supports strength gains, but evidence for hypertrophy advantages remains inconclusive. C_LI What this study addsO_LISynthesises evidence specifically in resistance-trained males ([&ge;]1 year RT experience). C_LIO_LIShows hypertrophy outcomes are trivial and do not favour longer ISRs over shorter ISRs. C_LIO_LIConfirms longer ISRs modestly improve strength and power, while hormonal and motor unit responses remain inconsistent. C_LIO_LIUnderscores the absence of robust evidence supporting longer ISRs as a superior hypertrophy strategy in trained populations. C_LI

ObjectivesTo describe the incidence, prevalence, characteristics, and management of shoulder injuries requiring medical attention in elite female cricket players. DesignRetrospective cohort. SettingAustralian state, territory, and national cricket teams between July 2015 and June 2023. ParticipantsElite female cricket players. Independent variablesMedical attention and general time-loss shoulder injuries. Main outcome measuresIncidence, prevalence, characteristics, recovery time-frames, activity modifications. Results409 shoulder injuries were recorded, with an average incidence of 12.9 per 100 players per season. Gradual onset injuries were most commonly experienced by pace bowlers (51%). Sudden onset injuries were most commonly sustained whilst fielding (69%). Four in five injuries did not require the player to be unavailable to play or train. Modified activities (e.g., throwing, diving, bowling) were typically required for between 2 weeks and 6 months. Players typically returned to full unrestricted match play between 1-8.5 months, longer for recurrent injuries (p=0.007). ConclusionsShoulder injuries are a considerable burden in elite female cricket players. Despite only one in five injuries resulting in a player being unavailable to play or train, impaired shoulder function may reduce the overall performance of the player and the team. Risk reduction strategies may be targeted to at risk players (pace bowlers) and activities (throwing and diving) to reduce the burden of shoulder injuries in this cohort. Further consideration may also be given to management strategies to reduce the risk of exacerbations and recurrent injuries which may prolong recovery.

Isokinetic dynamometry and neuromuscular electrical stimulation (NMES) are two commonly used approaches for quantifying muscle contractile properties. Few studies, however, have investigated the relationship between such testing procedures, particularly in women. PURPOSETo determine the relationship between voluntary isometric and isokinetic torque and torque during involuntary, electrically evoked contractions of the knee extensor muscles. METHODSThirty young women (age 23 {+/-} 5 y) performed maximal knee extensions on an isokinetic dynamometer at angular velocities of 0, 1.57, 3.14, 4.71, and 6.28 rad/s. Following this testing, NMES of the quadriceps (400 V, 200 {micro}s) was used to determine unpotentiated and potentiated twitch contractile properties. The quadriceps were also stimulated with 1 s trains at 1, 5, 10, 15, 20, 25, 30, 35, 40, 60, 80, and 100 Hz to determine the torque-frequency relationship. RESULTSVoluntary torques at 1.57 and 3.14 rad/s were significantly correlated (i.e., multiplicity-adjusted P[&le;]0.01) with the rate of torque development during potentiated twitches (r = 0.60 and 0.55, respectively). No other significant correlations were found between voluntary and involuntary muscle contractile properties, including various measures of the torque-frequency relationship. CONCLUSIONAlthough there is some relationship between voluntary and NMES indices of muscle contractility, such results are only moderately well-correlated at best. The two techniques should therefore be considered complementary rather than interchangeable. O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/24316419v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@8e14b7org.highwire.dtl.DTLVardef@1f22be7org.highwire.dtl.DTLVardef@2052deorg.highwire.dtl.DTLVardef@20a02d_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundAlthough the cardiovascular disease (CVD) benefits of both overall volume and intensity of physical activity (PA) are known, the role of PA intensity, over and above volume, is poorly understood. We aimed to investigate the interplay between PA volume and intensity in relation to incident CVD. MethodsData were from 88,412 UK Biobank participants without prevalent CVD (58% women) who wore an accelerometer on their dominant wrist for 7 days, from which we estimated total physical activity energy expenditure (PAEE) using population-specific validation. Cox proportional hazards regressions modelled associations between PAEE (kJ/kg/day)] and PA intensity [%MVPA; the fraction of PAEE accumulated from moderate-to-vigorous-intensity PA] with incident CVD, adjusted for potential confounders. ResultsThere were 4,068 CVD events during 584,568 person-years of follow-up (median 6.8 years). Higher PAEE and higher %MVPA (adjusted for PAEE) were associated with lower rates of incident CVD. In interaction analyses, CVD rates were 17% (95%CI: 8-26%) lower when MVPA accounted for 20% rather than 10% of 15 kJ/kg/d PAEE; equivalent to the difference between a 12-min stroll into a brisk 7-min walk. CVD rates did not differ significantly between values of PAEE when the %MVPA was fixed at 10%. However, the combination of higher PAEE and %MVPA was associated with lower CVD rates. Rates were 24% (10-35%) lower for 20 kJ/kg/d PAEE with 20% from MVPA, and 49% (23-66%) lower for 30 kJ/kg/d with 40% from MVPA (compared to 15 kJ/kg/d PAEE with 10% MVPA). ConclusionsReductions in CVD risk may be achievable through higher levels of PA volume and intensity, with the role of moderately intense PA appearing particularly important for future CVD risk. Our findings support multiple approaches or strategies to PA participation, some of which may be more practical or appealing to different individuals.

Cognitive control, defined as the allocation of mental resources required for goal-directed behaviour, is crucial for exercise participation as it is involved in regulating negative cognitive and affective responses caused by the demands of exercise. Research on both music and acute exercise separately show engagement of cognitive control processes and affective responses, with low-to-moderate exercise intensities reliably influencing cognitive and affective outcomes (e.g., core affect). However, the combined effects of music and acute exercise on cognitive control and affective outcomes remain underexplored. Accordingly, this review and meta-analysis explores how music influences cognitive control and affective outcomes during acute exercise. 10 studies met the inclusion criteria, with nine providing data for effect size calculations across 21 intervention arms. Meta-analyses revealed significant effects of music on attention allocation (g = 1.05, 95% CI [0.03, 2.07]; p = 0.04), inhibitory control (g = 1.87, 95% CI [0.37, 3.37]; p = 0.01), and core affect (g = 0.86, 95% CI [0.24, 1.48]; p < 0.01). Exercise intensity significantly moderated outcomes (p = 0.036), suggesting that higher intensities diminish the effectiveness of music in elevating cognitive control and affective outcomes during acute exercise. Findings were limited by high heterogeneity (I{superscript 2} > 97%) across study protocols and outcome measures. Due to the aforementioned heterogeneity, the findings of this review must be interpreted cautiously.

PurposeThis study examines the association between aerobic capacity and biomarkers of skeletal- and cardiac muscle damage among amateur triathletes after a full distance Ironman. MethodsMen and women (N=55) were recruited from local sport clubs. One month before an Iron-man triathlon, they conducted a 20m shuttle run test to determine aerobic capacity. Blood samples were taken immediately after finishing the triathlon, and analyzed for biomarkers of cardiac- and skeletal muscle damage. Regression models examining the association between aerobic capacity expressed in both relative terms (mLO2*kg-1*min-1) and absolute terms (LO2*min-1) controlled for weight and were fitted. ResultA total of 39 subjects (26% females) had complete data and were included in the analysis. No association between aerobic capacity and cardiac muscle damage but a significant negative association between aerobic capacity and skeletal muscle damage was observed. This association was independent of how aerobic capacity was expressed, although the model with aerobic capacity expressed in absolute terms and controlled for weight resulted in slightly higher r2 values, than when aerobic capacity was expressed in relative terms. ConclusionA negative association between aerobic capacity and skeletal muscle damage was seen but despite the well-known cardio-protective health effect of high aerobic fitness no such association could be observed in this study.

PurposeAn oxygen uptake ([V]O2) plateau, despite an increased work rate, is considered the gold standard for confirming if exercise test performance reflects maximal oxygen uptake ([V]O2max). We investigated whether adolescents demonstrate a [V]O2 plateau during an incremental test or if a supramaximal verification phase is necessary to confirm [V]O2max. We also investigated the impact of using moving versus binned time averages on [V]O2max values, and how these processing strategies influence the interpretation of the verification phase in confirming [V]O2max. MethodsA total of 27 adolescents (16 girls) aged 12 to 14 years completed an incremental cycle ergometer ramp test to exhaustion. After a 15-minute recovery, a verification phase was conducted at 105% of their incremental test peak power. [V]O2max was analysed using 15-second binned and moving averages. ResultsOut of 27 participants, 5 (19%) demonstrated a plateau in [V]O2 during an incremental test. [V]O2max was confirmed in the verification phase for 23 out of the 27 adolescents (85%). The moving [V]O2max (mL/kg/min) averages were higher than the binned [V]O2 values in the incremental test (1.8%) and the verification phase (2.4%) (P<0.0001). Processing strategies did not affect the confirmation of [V]O2max. ConclusionA verification phase is necessary for accurately determining [V]O2max in adolescents, who often do not reach a [V]O2 plateau. The processing strategies of exercise tests should be reported, as different strategies can lead to variations in [V]O2max results. However, these processing strategies do not impact the utility of the verification test.

ObjectiveTo compare multiple body composition analysis methods in athletes with varying states of hydration to the criterion 5-compartment model(5CM) of body composition and assess the relationships of technique-specific estimates of fat and fat-free mass(FM, FFM) to muscle strength. MethodsBody composition was assessed in 80(40-female) athletes with a mean age of 21.8{+/-}4.2 years. All athletes underwent laboratory-based methods: air-displacement plethysmography(ADP), deuterium-oxide dilution(D2O), dual-energy X-ray absorptiometry(DXA), underwater-weighing(UWW), and field-based: 3D-optical(3DO) imaging, and three bioelectrical impedance(BIA) devices(S10/SFB7/SOZO). Participants muscular strength was assessed by isokinetic/isometric dynamometry. Accuracy was assessed by Lins concordance correlation coefficient(CCC) and precision by root-mean-square coefficient of variation(RMS-CV%). ResultsAthletes hydration status(total body water/FFM) was significantly(p<0.05) outside of the normal range in both males(0.63-0.73%) and females(0.58-0.78%). The most accurate techniques(ADP/DXA) showed moderate-substantial agreement(CCC=0.90-0.95) in FM and FFM, whereas all field assessments had poor agreement(CCC<0.90), except 3DO FFM in females(CCC=0.91). All measures of FFM produced excellent <1.0% precision, whereas FM from ADP, DXA, D2O, S10, and UWW had <2.0%. The associations between muscle strength and the various devices FFM estimates differed. However, more accurate body composition compared to the criterion produced a better determination of muscle strength by significant quartile p-trends(p<0.001). The 5CM exhibits the highest determination for all categories of muscle strength which persisted across all hydration measures. ConclusionTo optimize accuracy in assessing body composition and muscle strength, researchers and clinicians should prioritize selecting devices based on their accuracy compared to the 5CM. Reliable approaches such as ADP and DXA yield accurate and precise body composition estimates and thereby, better strength assessments, regardless of hydration status. Future athlete studies should investigate the impact of changes in FFM on functional measures compared to the criterion method. Summary BoxThis study compared various body composition analysis methods in athletes with varying states of hydration to the criterion 5-compartment model(5CM) and assessed their relationship to muscle strength. The results showed that accurate and precise estimates of body composition can be determined in athletes, and a more accurate body composition measurement produced better strength estimates. The best laboratory-based techniques were air displacement plethysmography(ADP) and dual-energy x-ray absorptiometry(DXA), while field assessments had moderate-poor agreement. Prioritize accurate body composition assessment devices compared to the 5CM for better strength estimates in athletes.

BackgroundAnterior knee pain (AKP) is common in adolescent athletes and encompasses heterogeneous osseous and soft tissue pathologies, yet its developmental mechanisms remain poorly integrated. HypothesisPain-generating tissues within the knee extensor mechanism are redistributed from osseous to soft tissue structures with skeletal maturation. Study DesignRetrospective observational cohort study. Level of EvidenceLevel 3. MethodsA total of 1,595 patients with sports-related knee injuries (2017-2025) were included. Skeletal maturity was determined by proximal tibial physeal status on radiographs, classifying participants into open-physes (n = 707) and closed-physes (n = 888) groups. AKP was classified into bony and non-bony subtypes based on maximal tenderness. Prevalence was compared using odds ratios (ORs) with 95% confidence intervals (CIs). ResultsOverall, 575 patients (36.1%) had AKP. AKP was more prevalent in the open-physes group than in the closed-physes group (60.1% vs 16.9%; OR, 7.4; 95% CI, 5.9-9.3; p < 0.001). Bony AKP showed a marked difference (42.4% vs 3.7%; OR, 19.1; 95% CI, 12.8-28.6; p < 0.001), whereas non-bony AKP showed only a modest difference (17.7% vs 13.2%; OR, 1.4; 95% CI, 1.1-1.9; p = 0.013). ConclusionThe association between AKP and skeletal maturity was primarily driven by bony AKP, supporting structural redistribution of pain-generating tissues during growth. Clinical RelevanceTenderness-based classification may aid identification of tissue-specific vulnerability and inform growth-stage-specific load management.