Medicine & Science in Sports & Exercise

ObjectiveThis study aims to evaluate the short form International Physical Activity Questionnaire (IPAQ) for use in women with chronic pelvic pain disorders (CPPDs) by comparing its scores against objectively-estimated physical activity (PA) outcomes. We investigated IPAQ components that are most consistently predictive of habitual PA behavior. MethodThe study sample included 966 weeks of data from 112 women with CPPDs who enrolled in a 14-week mHealth-based self-tracking study. Participants wore Fitbit devices and completed the IPAQ every week. We compared the IPAQ-reported minutes of walking, total activity, sitting, light-, moderate-, and vigorous intensity PA for concordance and divergence against their corresponding Fitbit estimates. We used linear mixed-effects regression models (MLMs) for all analyses and quantified the between-participant variance in the magnitude of agreement between the two methods via random slope terms. We further evaluated temporal consistency in scores using intraclass correlation coefficients (ICCs). ResultsIPAQ-reported walking minutes were strongly associated with Fitbit step counts (B = 3952.36; p = 0.006), minutes of moderate PA (B = 15.498; p = 0.0113), and moderate-to-vigorous PA (MVPA; B = 28.973; p = 0.007). IPAQ total activity minutes were associated with Fitbit minutes of vigorous PA (B = 15.183; p = 0.007) and MVPA (B = 25.658; p = 0.010). IPAQ moderate activity minutes were predictive of Fitbit vigorous PA minutes (B = 9.060; SE = 3.719; p = 0.0151). There was substantial between-individual variance in these point estimates based on the significant random-effect terms, and average weekly PA level was a significant moderator of the association between IPAQ-reported and Fitbit-estimated scores for these variables. IPAQ-reported sitting minutes were inversely associated with Fitbit step counts (B = - 3125.61; p = 0.004), and minutes of MVPA (B = -21.848; p = 0.007), vigorous AP (B = -10.854; p = 0.042), and moderate PA (B = -10.985; p = 0.004). ConclusionThese findings provide support for using IPAQ-reported walking and total activity minutes to monitor several PA domains in women with CPPDs, given their concordance with several tracker-estimated PA outcomes. However, the item on "sitting time" may not be a suitable for assessing sedentary time.

BackgroundMaximal oxygen uptake (VO2 max), an indicator of cardiorespiratory fitness (CRF), requires exercise testing and, as a result, is rarely ascertained in large-scale population-based studies. Non-exercise algorithms are cost-effective methods to estimate VO2 max, but the existing models have limitations in generalizability and predictive power. This study aims to improve the non-exercise algorithms using machine learning (ML) methods and data from U.S. national population surveys. MethodsWe used the 1999-2004 data from the National Health and Nutrition Examination Survey (NHANES), in which a submaximal exercise test produced an estimate of the VO2max. We applied multiple supervised ML algorithms to build two models: a parsimonious model that used variables readily available in clinical practice, and an extended model that additionally included more complex variables from more Dual-Energy X-ray Absorptiometry (DEXA) and standard laboratory tests. We used Shapley additive explanation (SHAP) to interpret the new model and identify the key predictors. For comparison, existing non-exercise algorithms were applied unmodified to the testing set. ResultsAmong the 5,668 NHANES participants included in the final study population, the mean age was 32.5 years and 49.9% were women. Light Gradient Boosting Machine (LightGBM) had the best performance across multiple types of supervised ML algorithms. Compared with the best existing non-exercise algorithms that could be applied in NHANES, the parsimonious LightGBM model (RMSE: 8.51 ml/kg/min [95% CI: 7.73 -9.33]) and the extended model (RMSE: 8.26 ml/kg/min [95% CI: 7.44 -9.09]) significantly reducing the error by 15% (P <0.01) and 12% (P<0.01 for both), respectively. ConclusionOur non-exercise ML model provides a more accurate prediction of VO2 max for NHANES participants than existing non-exercise algorithms. What is KnownO_LIAlthough cardiorespiratory fitness is recognized as an important marker of cardiovascular health, it is not routinely measured because of the time and resources required to perform exercise tests. C_LIO_LINon-exercise algorithms are cost-effective alternatives to estimate cardiorespiratory fitness, but the existing models are restricted in generalizability and predictive power. C_LI What the Study AddsO_LIWe improve non-exercise algorithms for cardiorespiratory fitness prediction using advanced ML methods and a more comprehensive and representative data source from U.S. national population surveys. C_LIO_LIMore health factors that are associated with cardiorespiratory fitness are newly identified. C_LIO_LINationally representative estimates for cardiorespiratory fitness in the U.S. over the recent 20 years are generated. C_LI

BackgroundExertional heatstroke (EHS) is the most severe form of heat-related illness, occurring during sport competition or military training. Despite substantial progress in understanding its physiological mechanisms, current evidence suggests the need for broader models that also consider cognitive factors. MethodsWe propose a cognitive model of EHS and conduct a preliminary empirical validation through a case-control study using self-report measures. The central hypothesis is that EHS results from a disrupted cost-benefit trade-off during prolonged physical activity, specifically, an overvaluation of performance-related benefits due to excessive motivation, coupled with an undervaluation of exertion costs linked to low interoceptive awareness, characterized by disrupted processing of signals related to the bodys internal state. ResultsIndividuals with a history of EHS (cases, N=51) reported significantly lower interoceptive awareness and reduced trait mindfulness compared to controls (n=43). However, no difference was found in global motivation traits between groups. ConclusionThese findings provide initial support for a cognitive model of EHS and suggest that simple self-report tools may help identify individual vulnerability. Incorporating cognitive dimensions into EHS research could enhance risk stratification and inform new prevention strategies in athletic and military contexts.

Background Polygenic scores (PGSs) may help assess genetic predisposition to multifactorial traits. We examined whether age, sex, and leisure-time physical activity (LTPA) modify the association between a PGS for handgrip strength (HGS) and measured HGS in older adults. Methods PGS HGS, based on Pan-UK Biobank GWAS data, was calculated for 5103 participants (aged 40-96; 44% women) from eight twin cohorts in Denmark, Sweden, Australia, the United States, and Finland within the IGEMS consortium. Sex-standardized HGS and self-reported LTPA were assessed cross-sectionally. Linear mixed models estimated associations between PGS and HGS, including interactions with age, country, and LTPA, as well as an association between PGS and LTPA. Fixed-effect within-pair models were conducted to assess environmental contributions. Results Higher PGS was associated with greater HGS ({beta} = 2.14, SE = 0.15, p < 0.001), explaining 4.6% of HGS variance overall, with modest variation across countries. In sex-stratified models, PGS explained 5.2% of the variance in females and 4.3% in males. A significant PGS x LTPA interaction ({beta} = -0.034, p = 0.013) indicated that LTPA had a stronger effect among individuals with lower PGS HGS. No statistically significant interaction with age was found. The within-pair models offered limited support for the environmental impact of LTPA. Conclusions PGS for HGS was associated with measured HGS, with effect modification by LTPA. Findings provide some evidence that physical activity may buffer against genetic predisposition to lower HGS. The results highlight the potential of PGSs to capture individual differences in strength-related traits across populations.

ObjectivesGenetic variation in cytokine genes may influence inflammation, metabolism, and exercise-related adaptations, yet large-scale population data remain scarce. This study examined whether five polymorphisms in interleukin-6 (IL6; rs1800795, rs1800796, rs1800797), interleukin-15 (IL15; rs1589241), and tumour necrosis factor-alpha (TNF-; rs1800629) are associated with physiological, biochemical, and performance-related traits in healthy adults. MethodsA total of 1,000 healthy adults of European ancestry underwent comprehensive physiological, biochemical, and genomic assessments. Participants were classified according to objectively measured maximal oxygen uptake (VO2max), providing a quantitative marker of aerobic capacity rather than athlete-control contrasts. ResultsCarriers of the IL6 rs1800795 CC genotype showed higher serum iron (p = 0.004) and hematocrit (p = 0.033). The IL6 C-G-G haplotype (rs1800795-rs1800796-rs1800797) was also associated with higher iron levels (p = 0.0012). For TNF- rs1800629, AG and AA genotypes were less likely to belong to the higher VO2max group (p = 0.006). AG carriers also had nominally higher LDL cholesterol (p = 0.037), while AA carriers showed a trend toward a longer time to peak power in the Wingate test (p = 0.052). No significant single-locus effects were detected for IL15, but the IL15 CC/CT x TNF- GG combination was associated with greater odds of higher aerobic capacity (p = 0.004). ConclusionThese findings reveal modest but consistent genetic influences on iron metabolism, lipid profile, and aerobic capacity. Variants in IL6 and TNF- were linked to performance-relevant traits, while a multi-locus IL15 x TNF- interaction further supports the role of cytokine-related gene networks in individual differences in aerobic fitness and recovery potential. WHAT IS ALREADY KNOWN ON THIS TOPICO_LIGenes that regulate inflammation, such as interleukin-6 (IL6), interleukin-15 (IL15) and tumour necrosis factor-alpha (TNF-), may influence how people respond to exercise and recover after training. C_LIO_LIPrior studies were often small and compared athletes with non-athletes, rather than using an objective physiological classification like VO2max-leaving population-level links uncertain. C_LI WHAT THIS STUDY ADDSO_LIIn a study of 1,000 healthy European adults, IL6 variants were linked with higher iron and hematocrit - factors that can support oxygen transport and recovery. C_LIO_LIPeople carrying the TNF- A variant tended to have lower aerobic capacity, while a specific combination of IL15 and TNF- variants was linked to better aerobic fitness (higher VO2max). C_LI HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICYO_LIThese results suggest that differences in immune-related genes partly explain why people respond differently to training. C_LIO_LIVO2max-based genetic profiling could support more tailored training, recovery, and prevention strategies in sport and clinical practice. C_LI

BackgroundMindfulness meditation has been reported to reduce stress and enhance well-being. However, its effects on heart rate variability (HRV) - a physiological marker of stress - remain underexplored. ObjectiveTo examine how meditation practice is associated with subjective stress, HRV, and their interaction, using mobile health (mHealth) technologies. MethodsThis three-week observational study included 90 participants: 19 meditation practitioners, 32 recreational runners, and 39 individuals without regular meditation or exercise habits. HRV was continuously recorded using Garmin smartwatches. Subjective stress and activity were assessed three times daily via a smartphone-based experience sampling method (ESM), yielding 4,557 responses; 632 meditation sessions were time-logged; questionnaires were administered at the end of the study. ResultsStress (PSS) was lower in meditation and running groups vs. controls (Kruskal-Wallis P = .024; adjusted Wilcoxon P = .048 and .040). RMSSD was higher in runners vs. controls (P < .001) but not different between meditation and controls. Higher perceived stress was associated with concurrent RMSSD reduction of -2.24 ms (95% CI -3.97 to -0.26), steeper in runners (-3.94 ms; 95% CI -7.04 to -0.74). During meditation, RMSSD increased by +4.68 ms (95% CI 2.96 to 6.38) and remained elevated for at least 30 minutes post-practice. ConclusionsAlthough daily-life HRV among meditation practitioners was not elevated overall, their ability to increase HRV at will with a prolonged residual effect may relate to stress reduction and warrants further investigation. Trial RegistrationNot applicable.

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

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.

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.

This cross-sectional derivation and internal validation study aimed to develop and internally validate a clinical triage scoring system (CTSS) for field-based identification of collegiate athletes requiring priority intervention for lumbopelvic-hip (LPH) dysfunction. A total of 864 collegiate athletes (mean age 21.3 {+/-} 2.4 years; 80.8% male) were recruited from 10 universities. Participants underwent standardized assessments including demographic characteristics, clinical history, and LPH functional testing. Using an expert-adjudicated binary reference standard (priority intervention vs self-management), a multivariable logistic regression model was developed to derive the weighted CTSS. Model performance was evaluated using discrimination, calibration, and decision curve analysis (DCA), and internal validation was performed using 1,000 bootstrap resamples. Of the 864 participants, 463 athletes (53.6%) were classified as requiring priority intervention. The final 14-factor CTSS comprised 12 positive-weight predictors, such as localized LPH pain, muscle weakness, and higher body mass index, and 2 negative-weight predictors, positive Lasegues sign and hamstring weakness, which functioned served as safety-related modifiers. The model demonstrated acceptable discrimination (AUROC = 0.851, 95% CI: 0.824-0.876), with minimal optimism (optimism-corrected AUROC = 0.842) and excellent calibration (calibration slope = 1.000; calibration intercept = 0.000). A total score of [&ge;]9 was identified as the optimal threshold, yielding a sensitivity of 84.4% and specificity of 71.8%. DCA showed greater net benefit than treat-all and treat-none strategies across clinically relevant threshold probabilities (20%-50%), with a net benefit of 0.319 at a 50% threshold probability. The CTSS may provide a pragmatic field-based triage tool to support early identification of athletes who may require priority intervention, although external validation is needed before broader implementation in sports medicine settings.

BackgroundDespite the growing participation of female athletes in contact and high-impact sports, their representation in concussion research remains disproportionately low. This imbalance limits the generalizability of clinical guidelines and return-to-play (RTP) protocols, potentially compromising athlete safety and recovery outcomes. MethodsA systematic literature review was conducted on concussion studies published between 2021 and 2024 to assess changes in female representation. The analysis focused on three key objectives: (i) identifying primary research areas in concussion studies, (ii) evaluating the prevalence of female participants, and (iii) determining whether sample sizes were sufficient for statistically meaningful, sex-specific conclusions. ResultsA regression analysis revealed a statistically significant decline in female representation over time (B =-0.2478, p <.001), and female participant numbers decreasing 25% yearly and by 31% between 2021 and 2024. The female-to-male ratio analysis confirmed that male sample sizes continue to dominate, reinforcing the reliance on male-centric data in concussion assessment and RTP decision-making. Additionally, while generalized linear models remain widely used for broad comparisons, traditional statistical methods often fail to capture nuanced sex-based differences, particularly given the persistent sample size disparities. ConclusionThis review underscores the continued underrepresentation of female athletes in concussion research and the reliance on male-driven data for clinical decision-making. Although efforts to include female participants have increased, sample sizes remain insufficient for robust, sex-specific analyses. Addressing these gaps is critical for developing evidence-based, individualized concussion recovery models that account for the unique neurobiological and biomechanical profiles of female athletes.

PurposeConsistently performing at the highest level in golf requires a complex interplay of physiological and psychological attributes, with success often defined by razor-thin margins. Sleep characteristics and cardiac autonomic function, reflected by resting heart rate (RHR) and heart rate variability (HRV), are key indicators of recovery and readiness to perform. Yet, their relevance to elite golf performance remains largely unexplored. MethodsWe analyzed wearable-derived longitudinal data from 389 professional tour-level golfers across 521 competitive events (2017-2025), encompassing 35,140 nights of sleep and biometric monitoring. Key metrics included sleep duration (7.2{+/-}0.7hrs), sleep consistency (69.1{+/-}6.9%), RHR (55.9{+/-}7.9bpm), HRV (64.2{+/-}28.1ms), and a composite Recovery score (59.1{+/-}9.9%). Golf performance (total score, great shots, poor shots, strokes gained) was extracted from a subscription-based database. Linear mixed-effects models assessed both between-person differences and within-person season-to-season changes, adjusting for age (34.1{+/-}9.1yrs), height (1.81{+/-}0.07m), and weight (83.2{+/-}10.6kg). ResultsGolfers with superior sleep and biometric profiles consistently performed better, both between and within individuals (Ps<0.05). Between individuals, each additional hour of sleep was associated with a lower score (b=-0.522), as was a 10-percentage point increase in sleep consistency (b=-0.382), a 1bpm lower RHR (b=-0.038), and a 10-percentage point increase in Recovery (b=-0.476). Within athletes, season-to-season improvements in sleep consistency (b=-0.193 per 10-percentage points), HRV (b=-0.016 per 1ms), and Recovery (b=-0.238 per 10 percentage points) were also associated with lower scores (Ps<0.05). ConclusionsSleep and measures of cardiac autonomic function are associated with performance in elite golf. Both individual differences and within-athlete improvements were linked to success, highlighting the potential role of sleep, resting heart rate, and heart rate variability in optimizing performance at the highest level of sport.

BackgroundTo examine the association between COVID-19 vaccination status and physical activity (PA), sporting behavior, as well as barriers to PA in adults in Switzerland, Germany, and Austria. MethodsA total of 1516 adults provided complete responses to our online questionnaire sent out in August 2021. Information about self-reported PA categories, sporting behavior, barriers to PA, and COVID-19 vaccination status were gathered. Main analyses were done using multiple linear regression adjusted for relevant parameters. ResultsWe found a significant association of vaccination status with total PA (p = .011), vigorous PA (p = .015), and moderate PA (p = .001) but not transport-related PA or sedentary time. Unvaccinated adults tended to have more total and vigorous PA than those vaccinated once (ratios of geometric means: 1.34 and 1.60, respectively) or twice (1.22 and 1.09, respectively). Yet, not sufficient evidence was available to confirm this. There was no between-group difference in the contribution of leisure time, work-related, or transport-related PA to total PA. Vaccination status was not associated with sporting behavior except for jogging as the primary intensive type of sports. Finally, there were no significant differences in any of the COVID-19 specific barriers to PA between groups. ConclusionOur data showed that vaccination status is associated with PA even in summer, where the number of COVID-19 cases was low and the severity of safety measures was mild. These findings may enhance future research and improve/extend COVID-19-specific PA guidelines.

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.

BackgroundModerate-to-vigorous physical activity (MVPA), light physical activity, sedentary behaviour and sleep have all been associated with cardiovascular disease (CVD). Due to challenges in measuring and analysing movement behaviours, there is uncertainty about how the association with incident CVD varies with the time spent in these different movement behaviours. MethodsWe developed a machine-learning model (Random Forest smoothed by a Hidden Markov model) to classify sleep, sedentary behaviour, light physical activity and MVPA from accelerometer data. The model was developed using data from a free-living study of 152 participants who wore an Axivity AX3 accelerometer on the wrist while also wearing a camera and completing a time use diary. Participants in UK Biobank, a prospective cohort study, were asked to wear an accelerometer (of the same type) for seven days, and we applied our machine-learning model to classify their movement behaviours. Using Compositional Data Analysis Cox regression, we investigated how reallocating time between movement behaviours was associated with CVD incidence. FindingsWe classified accelerometer data as sleep, sedentary behaviour, light physical activity or MVPA with a mean accuracy of 88% (95% CI: 87, 89) and Cohens kappa of 0{middle dot}80 (95% CI: 0{middle dot}79, 0{middle dot}82). Among 87,509 UK Biobank participants, there were 3,424 incident CVD events. Reallocating time from any behaviour to MVPA, or reallocating time from sedentary behaviour to any behaviour, was associated with a lower risk of CVD. For example, for a hypothetical average individual, reallocating 20 minutes/day to MVPA from all other behaviours proportionally was associated with 9% (7%, 10%) lower risk of incident CVD, while reallocating 1 hour/day to sedentary behaviour was associated with 5% (3%, 7%) higher risk. InterpretationReallocating time from light physical activity, sedentary behaviour or sleep to MVPA, or reallocating time from sedentary behaviour to other behaviours, was associated with lower risk of incident CVD. Accurate classification of movement behaviours using machine-learning and statistical methods to address the compositional nature of movement behaviours enabled these insights. Public health interventions and guidelines should promote reallocating time to MVPA from other behaviours, as well as reallocating time from sedentary behaviour to light physical activity. FundingMedical Research Council.

BackgroundSedentarism is prevalent and associated with poorer mental and physical health. Whether everyday physical activity (PA) maps onto computational decision strategies and brain structure/function in non-elderly adults remains unclear. MethodsSeventy-one healthy adults (39 women; 18-45 years) completed the Multi-Source Interference Task (MSIT) during fMRI. PA was quantified with the short IPAQ and participants were classified as Active or Sedentary. Behavior (RT, accuracy) was analyzed with frequentist models and a hierarchical Bayesian drift-diffusion model (DDM) estimating drift rate (v), boundary separation (), and non-decision time ({tau}). First-level fMRI modeled congruent/incongruent trials; group-level analyses used FLAME1 with cluster-wise FWE correction (z>3.1, p <.05). Structural MRI was processed with FreeSurfer 7.4.1 (cortical thickness, hippocampal subfields); surface-based GLMs tested group and DDM effects. ResultsActive participants responded faster overall; incongruent accuracy showed a speed- accuracy trade-off (accuracy increased with slower RTs), with a significant RT x group interaction. In the DDM, boundary separation () was higher in sedentary individuals (greater caution), whereas drift rate (v) differed by sex (males > females). Structurally, the active group showed larger left hippocampal subfields and thicker cortex in posterior temporal & anterior cingulate regions that are negatively related to . Functionally, boundary-related BOLD modulation encompassed fusiform, posterior cingulate, superior temporal cortex, and SMA; Active > Sedentary contrasts highlighted left occipital and inferior parietal lobe. ConclusionsEveryday PA aligns with lower decision thresholds, select structural advantages, and more efficient task-engaged networks, suggesting PA fosters adaptive, resource-efficient cognitive control. These mechanistic links support PA-based strategies to mitigate risks of sedentarism.

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.

There is current scientific and legal controversy about sports competition eligibility regulations for transgender athletes. To better understand and contextualize the effect of androgen-suppression treatment on swimming performance, we compared the gender-related differences in performance of a transgender swimmer who competed in both the male and female NCAA (collegiate) categories to the sex-related differences in performance of world and national class swimmers. These data demonstrate that the gender-related differences in middle distance freestyle performances of a transgender woman are smaller than the observed sex-related differences in performance of top athletes. Our analysis may be useful as a framework for regulators considering participation guidelines which promote fair competition for all athletes, whether cisgender or transgender. One-Sentence SummaryRecent outstanding performances by a transgender woman swimmer are faster than predictions based on historic sex-related differences in swimming performance.

BackgroundThere is a high prevalence of musculoskeletal (MSK) pain and extensive training volume among professional and amateur esport players. MSK pain has been found to limit esports participation in 6% of players. Further, there is an increasing concern that the training volume may lead to activity-limiting burnout in esports. However, it remains to be investigated if MSK pain and activity-limiting burnout is more prevalent in esports compared to traditional sports such as handball. The objectives were 1) to compare MSK pain prevalence between esports players and handball players and 2) to investigate if MSK pain is associated with training volume in the two groups. MethodsEligible players had to engage in either structured esports or handball and be 15-25 years of age to participate in this questionnaire-based cross-sectional study. Esports players had to engage in esports primarily through a computer-based game. Demographic data, self-reported MSK pain prevalence, training volume, sleep patterns, physical activity level and activity-limiting pain and burnout were obtained through online questionnaires. The primary outcome was any MSK pain during the previous week (yes/no). Results76 esports players and 175 handball players were included. 48% of esports players and 80% of handball players experienced MSK pain during the previous week. The likelihood of MSK pain was significantly lower in esport compared to handball (OR 0.24, 95%CI [0.13-0.43], Chi2 p-value < 0.001). No significant differences in training volume among participants with or without MSK pain were found in neither esports (p-value = 0.727) nor in handball (p-value = 0.128). There was a significant difference in training volume with esports player practicing for additional 12 hours per week compared to handball players (p-value < 0.001). The occurrence of activity-limiting burnout was high in both esports (34%) and handball (37%). ConclusionThese findings suggest that young esports players are not at increased health risk in terms of experiencing MSK pain compared to young players participating in handball. This despite esports players practiced their activity for 12 hours more per week compared to handball players. More than 1 in every 3 had experienced activity-limiting burnout in both esports and handball despite a significant difference in weekly training volume. This indicate that other factors besides type of activity and training volume may influence the occurrence of activity-limiting burnout.

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.