Medicine & Science in Sports & Exercise

Energy expenditure (EE) during running depends on the interplay between active muscle work and elastic energy storage and return, yet the relative contribution of mechanical power to EE remains debated. Quantifying the relative contributions of segment-level mechanical power can provide a way to address this debate. In this study, we aimed to quantify how segment-level mechanical power contributes to EE during running and to demonstrate that these mechanistic insights support wearable-based EE estimation. Joint dynamics and respiratory gas-based EE were collected from healthy young adults running at multiple speeds. Scale factors were derived to quantitatively link efficiency-weighted segment power to measured EE. The stance leg consistently showed the strongest correlation with EE, and this dominance was preserved across speeds. Including swing-leg hip power further improved accuracy. Scale factors were approximately 0.45, suggesting that active muscle work and elastic energy return contribute comparably to the mechanical power associated with EE. Using a lightweight machine learning model, stance-leg and swing-leg hip joint power were reconstructed from a single sacral IMU, enabling accurate EE prediction. These findings demonstrate that lower-limb mechanical power is a robust predictor of running EE, supporting both the extensibility of biomechanically-informed frameworks and wearable-based EE monitoring.

Background: Clinical malnutrition affects one in five abdominal surgery patients and increases postoperative complications and mortality. Current screening occurs after admission, closing the window for preoperative nutritional intervention. No objective, scalable preoperative screening tool exists. Objective: To determine whether automated volumetric CT-based body composition analysis improves preoperative identification of surgical patients at risk for clinical malnutrition compared to clinical variables or single slice imaging alone. Methods: Retrospective cohort study of adults undergoing elective abdominal surgery at a quaternary academic medical center (2018 to 2021) with a preoperative CT scan within 90 days and complete nutrition assessment. Clinical malnutrition was diagnosed by a registered dietitian using ASPEN/AND criteria. Three sex stratified Elastic Net models were compared: (1) base clinical variables; (2) base plus L3 single slice skeletal muscle index and attenuation; and (3) base plus comprehensive 3D volumetric quantification of five muscle groups and two fat depots. Discrimination (AUROC), calibration (Brier score), and clinical utility (decision curve analysis) were assessed via 10-fold cross-validation. Results: Among 1,143 patients (52.4% female; mean age 60.5 years), 231 (20.2%) were diagnosed with malnutrition. Malnourished patients had significantly higher complication rates (36.4% vs. 15.4%, p<0.001) and prolonged length of stay (45.9% vs. 16.4%, p<0.001). Critically, 27.2% of malnourished patients were not flagged as at-risk by the standard Malnutrition Screening Tool. The volumetric model (Model 3) achieved the highest discrimination (males: AUROC 0.808; females: 0.794) and best calibration (males: Brier 0.129; females: 0.124), significantly outperforming both the base model (males: p=0.004; females: p<0.001) and L3 model (males: p=0.019; females: p<0.001). L3 features modestly improved discrimination but paradoxically worsened calibration; an effect corrected by volumetric features. Sex-specific risk profiles differed markedly, with ASA classification dominating female models and demographic factors dominating male models. Conclusions: Automated volumetric CT body composition analysis significantly improves preoperative malnutrition risk identification, with sex-stratified models revealing distinct risk profiles. Leveraging imaging already obtained for surgical planning, this approach opens a preoperative window for nutritional intervention that current practice fails to utilize.

Objective To analyze the associations between cardiorespiratory fitness (CRF) indicators and cardiovascular health, assessed through the Life's Essential 8 (LE8) score, in individuals with coronary artery disease (CAD). Patients and methods This cross-sectional study included individuals (aged 50-75 years) with stable CAD were enrolled in the Heart-Brain randomized controlled trial (NCT06214624) from April 2022 to June 2024. Participants underwent a cardiopulmonary exercise test until volitional exhaustion. CRF indicators included peak oxygen consumption (VO2peak), time to exhaustion (TTE), ventilatory anaerobic threshold (VAT), peak oxygen pulse, 60-s heart rate recovery (HRrec) and oxygen uptake efficiency slope (OUES). LE8 score (range 0-100) was calculated as the unweighted average of 8 variables: physical activity, sleep, diet, nicotine exposure, glucose, lipids, body mass index, and blood pressure, as defined by the American Heart Association. We used linear regression models adjusted for sex, age, and education. Results 102 individuals were included (21 females). VO2peak ({beta}std=0.67, P<.001) and TTE ({beta}std=0.64, P<.001) showed strong positive associations with LE8 total score, followed by VAT ({beta}std=0.43, P<.001) and HRrec ({beta}std=0.26, P=.01). No associations were found for OUES ({beta}std=-0.08, P=.54) and peak oxygen pulse ({beta}std=-0.05, P=.72). Conclusion Maximal and submaximal indicators of CRF were positively associated with LE8 in individuals with CAD, yet maximal indicators showed the strongest associations. Notably, TTE demonstrated a similar strength of association with LE8 as VO2peak. These findings have important clinical and research implications as they support TTE as a simpler (than the gold-standard VO2peak), yet informative, marker of cardiovascular health in individuals with CAD.

Background While weekend warrior (WW) physical activity (PA) pattern has been associated with cardiovascular benefits, most existing evidence is based on self-reported PA. Evidence using harmonized, thigh-worn accelerometry to examine associations between the weekend warrior phenotype and comprehensive cardiometabolic profiles remains limited. Methods We pooled harmonized individual-participant data from six cohorts in the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. In this cross-sectional analysis, participants were classified as inactive (<150 min/week MVPA), weekend warriors (150 min/week with 50% accumulated on 1-2 days), or regularly active 150 min/week but not meeting the WW criterion). A composite cardiometabolic score averaged eight standardized indicators: triglycerides, HDL cholesterol, total cholesterol, HbA1c, body mass index, waist circumference, systolic blood pressure, and diastolic blood pressure. Generalized linear models were used to estimate associations between PA patterns and both composite and individual cardiometabolic outcomes, adjusted for age, sex, smoking, alcohol intake, self-rated health, CVD history, medication use, blood biomarker fasting status, and cohort. Results Among 13,904 adults (mean age 54.3{+/-}9.5 years; 54.7% women), 61.8% were inactive, 24.5% weekend warriors, and 13.7% regularly active. Compared with inactivity, both active patterns were associated with more favorable composite cardiometabolic scores (WW: = -0.118 (95% CI: -0.142, -0.095); regularly active: = -0.111 (95% CI: -0.141, -0.081)), with negative values indicating better cardiometabolic health. Weekend warriors and regularly active adults showed broadly similar associations across individual markers, including lower adiposity (BMI and waist circumference) and more favorable metabolic biomarkers (higher HDL cholesterol; lower triglycerides and HbA1c), with no meaningful differences between the two active patterns for the composite score or any individual outcome. Associations with total cholesterol and blood pressure were small. Conclusions Both active patterns were associated with more favorable cardiometabolic profiles than inactivity, and profiles were broadly comparable whether MVPA was concentrated on 1-2 most active days (weekend warrior) or accumulated more regularly across the week. Keywords: weekend warrior; physical activity; accelerometry; cardiometabolic health

The metabolic cost of walking is widely used to evaluate human performance and effectiveness of clinical interventions. Decades of laboratory research, largely based on treadmill experiments, have established a canonical relationship between walking speed and metabolic cost, and suggested that ageing shifts this relationship upward, implying reduced efficiency in older adults. However, this relationship has not been well tested during overground walking across matched speeds. We compared healthy younger (n=16; 26{+/-}2yr) and older (n=11; 74{+/-}3yr) adults across eight outdoor overground walking trials at different speeds: preferred walking speed (PWS), three fixed speeds (0.8, 1.2, 1.6 m{middle dot}s-{superscript 1}), and four speeds at {+/-}5% and {+/-}10% of PWS. Contrary to our hypothesis, older adults did not show higher gross or net metabolic cost of walking (GCOW and NCOW) than younger adults at any speed; rather, both trended consistently lower in older adults, reaching significance for GCOW at 0.8 m{middle dot}s-{superscript 1} only. Comparisons of resting metabolic rate and respiratory exchange ratio to prior reference groups did not indicate that our older cohort was unusually fit. Independent of age, GCOW was significantly higher at 0.8 m{middle dot}s-{superscript 1} than at the remaining speeds (1.2-1.6 m{middle dot}s-{superscript 1}), confirming that walking at slower speeds increases GCOW. These findings challenge the view that ageing intrinsically increases the energetic cost of walking, suggesting instead that previously reported upward shifts in cost may reflect treadmill-specific constraints or speed effects. Future work is needed to explore direct comparisons of outdoor, overground walking with treadmill walking at fixed speeds in both younger and older adults.

Introduction: obesity and unhealthy weight gain during pregnancy are associated with risk of pregnancy complications. Management of energy balance during pregnancy needs an accurate assessment of intake and energy expenditure. As pregnancy promotes specific physiological changes, energy expenditure during rest and activity throughout this period may be altered. The aim of this study was to estimate with accurate methods changes in energy expenditure, substrate oxidation and efficiency during the most common activity in pregnancy that is walking. Methodology: it was a prospective observational study during pregnancy. A graded steady state walking submaximal exercise test was used to calculate indirect calorimetry variables with a portable metabolic cart at each trimester of pregnancy in 30 healthy pregnant women. Walking energy expenditure (WEE), carbohydrate (CarbOx) and fat oxidation (FatOx) were calculated with exercise intensity specific stoichiometric equations from measured oxygen consumption (VO2) and carbon dioxide production (VCO2). Resting component was removed from WEE to calculate net walking energy expenditure (Net WEE). Moreover, participants were classified as having healthy or unhealthy gestational weight gain (GWG) according to the Institute of Medicine (IOM) recommendations. Changes in body weight during the study were used to adjust net WEE and substrate oxidation. Walking exercise efficiency was calculated as work rate (WR) divided by WEE or net WEE. Differences in main variables during pregnancy were analyzed using a general lineal model. Least square means analyses were utilized to compare differences in WEE, Net WEE, and substrate oxidation between healthy and unhealthy weight gain groups. Results: Net WEE increased significantly during pregnancy. Higher rates were found between the second and the third trimester of pregnancy at any given speed. This elevation was reflected in increased FatOx during moderate intensity exercise and higher CarbOx at the fastest walking speed. Therefore, a significant interaction time*speed for NetWEE and substrate oxidation was found. Weight gain was an important variable in energy expenditure and substrate oxidation as quantitative differences in NetWEE and CarbOx were due to change in weight registered during the study. Changes in Net WEE throughout pregnancy were higher in the unhealthy GWG group which expended significantly more CarbOx than the healthy group at each speed. Overall, efficiency decreases during pregnancy (1.48% from the second to the third trimester and 1.88% from the first to the third one) and pregnant women were more efficient in moderate intensity exercise (walking at 4 km/h) independently of the trimester of pregnancy. Conclusion: The results suggest a paradoxical intensity-dependent substrate oxidation selection during walking exercise throughout pregnancy as in no-trained pregnant women the increase in WEE relies on fat oxidation in a short bout of activity. The results may be relevant for the management strategies in obesity and excessive GWG during pregnancy.

Pedalling cadence during an acute eccentric cycling exercise altered physiological and perceptual responses. We examined the influence of cycling cadence on neuromuscular adaptation induced by a 6-week eccentric cycling training period. Eighteen participants performed training (eighteen sessions) at a cadence of 30 or 60 rpm over six weeks. Power output was the same between the two groups. Perceived effort and heart rate were recorded at each training session. Muscle pain and fatigue were reported the day after each session. Maximal voluntary contractions torque, as well as concentric and eccentric cycling efficiency, were assessed before and after training. Additionally, the loss of maximal voluntary isometric torque was assessed after the first and last training sessions. Heart rate and perceived effort increased in the second week of training and then plateaued, with no difference between groups. Muscle pain and fatigue remained low throughout the training, with no difference between groups. Isometric (+28%) and eccentric (+13%) maximal voluntary torque of knee extensor muscles increased regardless of training cadence. Concentric maximal voluntary torque increased for the group pedalling at 60 rpm only (+21%). Cycling efficiency was improved in eccentric mode only (+43%), with no difference between the two training groups. Finally, the voluntary isometric torque loss induced by the first and last sessions were similar. While six weeks of eccentric cycling training improved neuromuscular and functional capacities, cadence had no observable effect. This finding suggest that patients could choose their preferred cadence to obtain better adherence to the rehabilitation program without altering the adaptations.

Objectives: To describe device-measured movement behaviours in a large sample of middle-aged and older Australian adults using complementary posture- and intensity-based accelerometers, examine variation across demographic groups, and identify behavioural phenotypes using clustering approaches Design: Cross-sectional analysis of the Australian Breakthrough Cancer (ABC) Study Accelerometer Sub-study (ACM). Methods: Participants from the ABC cohort completed seven days of simultaneous monitoring using a thigh-mounted activPAL and waist-mounted ActiGraph GT3X+. activPAL characterised posture-based behaviours (sitting, lying, standing, stepping, postural transitions, and sedentary accumulation), while ActiGraph characterised intensity-based activity (sedentary, light, and moderate-to-vigorous physical activity [MVPA]). Movement behaviours were summarised overall and by gender, age group, body mass index (BMI), and education. Behavioural phenotypes were identified using k-means clustering. Results: Among 4,238 ACM participants, 3,426 met inclusion criteria with valid data from both devices (1,711 females; 1,715 males). Participants accumulated substantially more time in sedentary and low-intensity behaviours than in MVPA. activPAL estimates indicated mean daily time of 379.3 min sitting, 282.2 min lying, 160.8 min standing, and 64.5 min stepping, with a mean of 5,185 steps/day. ActiGraph estimates indicated 584.0 min/day sedentary time, 290.9 min/day light-intensity activity, and 33.2 min/day MVPA. Considerable heterogeneity in movement behaviours was observed between individuals, whereas demographic differences were comparatively modest. Three behavioural phenotypes were identified: active/fragmented (24%), low activity (41%), and prolonged sedentary (35%). Notably, the low-activity and prolonged sedentary phenotypes were distinct, indicating that low overall movement and prolonged uninterrupted sitting represented different behavioural patterns. The prolonged sedentary phenotype was characterised by greater uninterrupted sitting time, lower stepping time, fewer steps, lower MVPA, and fewer sit-to-stand transitions. Conclusions: Movement behaviours in middle-aged to older Australian adults (40-74 yrs) were characterised by high sedentary time, low accumulation of MVPA, and substantial between-person heterogeneity. Distinct behavioural phenotypes highlighted differences in both movement volume and sedentary accumulation patterns, suggesting that movement behaviour is multidimensional and not adequately described by single summary measures alone. These findings may help inform our understanding of population movement patterns relevant to cancer and cardiometabolic disease prevention. Key words: Accelerometry, Motor Activity, Sedentary Behaviors, Cluster Analysis, Postural Allocation, Behavioural Phenotypes

Purpose Postprandial sedentary behavior is associated with negative health effects and constitutes a large part of daily life in modern society. This study investigated how the timing of physical activity after eating influences glucose levels, cerebral and muscle oxygenation, cognitive performance, and well-being during subsequent sitting. Methods In a four-armed randomized crossover trial, healthy adults consumed four standardized meals separated by 48-hour washout periods. Each meal was followed by 2 hours of sitting combined, in random order, with one of four interventions: (1) sitting only, (2) 15 minutes of moderate intensity cycling immediately after eating, (3) 15 minutes of cycling 20 minutes after eating, or (4) three workload-matched five-minute cycling bouts during sitting. Interstitial glucose (continuous glucose monitoring), cerebral and muscle oxygenation (Functional near infrared spectroscopy), cognitive performance (Stroop test), heart rate, blood pressure, and subjective ratings were assessed every 30 minutes. Data were analyzed using repeated-measures ANOVA. Results Twenty participants (mean age 27.1{+/-}10.3 years, 12 females) completed the study. Cycling immediately after eating reduced mean glucose levels during postprandial sitting, while both 15-minute cycling bouts increased cerebral oxygenation. All active conditions enhanced muscle oxygenation. Heart rate and arousal increased with delayed cycling and active breaks. No effects were observed for blood pressure, cognitive performance, focus, or well-being. Conclusion A short bout of physical activity immediately after eating reduces postprandial hyperglycemia and improves brain oxygenation during sitting, whereas delayed activity and brief breaks increase physiological activation without cognitive or perceptual benefits.

This study examined how lower-body lengthened partial (LP) versus full range of motion (FULL) resistance training affects acute post-exercise signaling, chronic hypertrophy, and cellular adaptations of the vastus lateralis (VL) muscle in resistance-trained men. Eight males (22{+/-}1 years old, 5.6{+/-}1.4 years training) completed a crossover study whereby VL biopsies were collected pre-exercise and 0, 3, and 24 hours following LP and FULL leg extension bouts for transcriptomic and anabolic signaling analyses (Experiment 1). Another 16 males (26{+/-}5 years old; 8.0{+/-}4.9 years training) completed an 8-week, twice-weekly lower-body intervention using a within-subject design (Experiment 2). One leg was assigned to FULL and the contralateral leg to LP training across three exercises (leg press, leg extension, and lying leg curl). Pre- and post-intervention outcomes included VL muscle cross-sectional area (mCSA) summed across five equidistant MRI-derived transverse slices and mid-thigh VL biopsy outcomes. As a secondary outcome, other hip and thigh muscles from Experiment 2 MRI scans were assessed. Condition x Time interactions for all outcomes were assessed using linear mixed-effects models. In Experiment 1, both conditions produced similar time-dependent changes in the VL transcriptome and anabolic (mTORC1 and Hippo) signaling, but minimal between-protocol interactions. In Experiment 2, VL summed mCSA significantly increased over time (mean change: 9.3 cm{superscript 2}, 95% CI [6.8, 11.8], P<0.001), but there was no clear evidence of differential change between protocols (LP-FULL change: -1.4 cm{superscript 2}, 95% CI [-6.1, 3.8], P=0.640). Additionally, no significant interactions existed for type I fiber CSA (P=0.476), type II fiber CSA (P=0.350), type I fiber myonuclei (P=0.813), type II fiber myonuclei (P=0.589), type I and II satellite cell number (P=0.102 and P=0.797, respectively), or total RNA content (P=0.537). Despite these null VL-centric findings, secondary Experiment 2 analyses provided some evidence that whole hamstring hypertrophy was greater following LP versus FULL (LP-FULL change: 3.9 cm{superscript 2}, 95% CI [-0.2, 7.9], P=0.058). In conclusion, 8 weeks of LP and FULL resistance training broadly elicit similar acute and chronic VL responses in previously trained men, though secondary hamstring findings suggest that differential responses may depend on exercises included in the resistance training program.

ABSTRACT Background: Athletes who return to soccer after anterior cruciate ligament reconstruction (ACLR) remain at elevated risk of secondary injury despite meeting conventional discharge criteria, and neuromuscular deficits in the reconstructed limb are known to be exposed by fatigue. Objective: To determine whether match-play fatigue differentially affects muscle stiffness, countermovement jump (CMJ) force symmetry, and rate of force development (RFD) asymmetry between soccer players with a history of ACLR and uninjured teammates. Methods: A prospective, cross-sectional, matched-control study enrolled 128 competitive soccer players (64 ACLR, 6-22 months post-surgery; 64 uninjured controls) across five recruitment waves (February-June 2026). Bilateral CMJ peak vertical force, jump height, RFD, and myotonometric stiffness of the rectus femoris (RF), vastus medialis (VM), and biceps femoris (BF) were recorded immediately before and after a standardized competitive match. Fatigue was quantified from second-half heart rate (percentage of age-predicted maximum) and end-match rating of perceived exertion (RPE). Within-group pre-to-post changes were evaluated with paired t-tests, between-group differences in the magnitude of change with independent-samples t-tests, and associations between fatigue indices and asymmetry changes with Pearson correlations. Results: Match play reduced CMJ limb symmetry index (LSI) in both groups, but the decline was more than three-fold greater in the ACLR group, 92.6% (SD 5.4%) to 85.1% (SD 7.1%), than in control group, 97.3% (SD 3.9%) to 95.0% (SD 4.2%), group-by-time difference, p < 0.001, (d = 0.64). RFD asymmetry approximately doubled in the ACLR group, 10.6% (SD 4.1%) to 17.6% (SD 6.5%), compared with a smaller rise in control group, 4.6% (SD 2.4%) to 6.3% (SD 3.7%); p < 0.001, d = 0.77). Involved-limb stiffness losses in the ACLR group exceeded those of controls for the RF (-21.2 vs. -9.2 N/m, p < 0.001), VM (-17.7 vs. -6.1 N/m, p < 0.001), and BF (-13.3 vs. -6.6 N/m, p < 0.001), whereas uninvolved-limb stiffness losses did not differ between groups (all p > 0.05). Fatigue markers (heart rate, RPE) were not significantly correlated with the magnitude of individual asymmetry change (|r| [&le;] 0.18, p > 0.15). Conclusions: In competitive soccer players 6-22 months after ACLR, match-play fatigue selectively compromises stiffness and explosive force output of the reconstructed limb, widening inter-limb asymmetries beyond what is seen in uninjured teammates, even though global cardiovascular and perceptual fatigue were comparable between groups. These findings suggest that return-to-sport testing performed only in a rested state may underestimate residual neuromuscular deficits, and support fatigue-inclusive assessment protocols before athletes are cleared for unrestricted competition. Abbreviations: ACL: anterior cruciate ligament, ACLR: anterior cruciate ligament reconstruction, BF: biceps femoris, CMJ: countermovement jump, HRmax: maximum heart rate, LSI: limb symmetry index, RF: rectus femoris, RFD: rate of force development, RPE: rating of perceived exertion, RTS: return to sport, VM: vastus medialis, SD: standard deviation. Keywords: Anterior cruciate ligament reconstruction, muscle fatigue, muscle stiffness, countermovement jump, limb symmetry index, rate of force development, soccer, return to sport.

Running can improve mood, but the proximal processes linking exercise-induced bodily changes to subjective affective changes remain unclear. Interoception, the sensing and interpretation of internal bodily signals, is central to how bodily states are integrated into emotional experience and may therefore link exercise-induced bodily changes to mood. Here we tested whether interoception links acute running to mood improvement. Twenty-seven healthy young adults completed a crossover experiment consisting of a 15-min moderate-intensity treadmill running condition and a seated rest condition, each performed on separate days. Interoceptive accuracy was assessed using heartbeat counting and tapping tasks. Present-moment interoceptive sensibility was monitored using a state-adapted Body Perception Questionnaire, and mood state was monitored using the Profile of Mood States. Compared with seated rest, running reduced total mood disturbance and tension-anxiety, increased vigor-activity, and enhanced heartbeat-signal discrimination and interoceptive sensibility. Running-related increases in interoceptive sensibility were associated with greater reductions in total mood disturbance and tension-anxiety. Mediation analyses further indicated that changes in interoceptive sensibility partially mediated the effect of running on total mood disturbance, with weaker evidence for tension-anxiety. These findings suggest that enhanced interoceptive sensibility may represent one proximal process through which acute running improves mood states.

Purpose: Physical behaviors, including physical activity, sedentary time, and sleep, are associated with health and together comprise the 24-hour day. Among working-aged adults, the composition of these 24-hour physical behaviors may vary across occupations, but the extent of these differences remains unknown. This population-based study examined how the composition of 24-hour physical behaviors differs in working-aged adults across occupational groups during work and leisure time. Methods: The study population consisted of 2,809 adults from the Northern Finland Birth Cohort 1966 46-year follow-up study, who wore a hip-worn accelerometer for 14 days. The accelerometry data was combined with self-reported diaries to determine time in bed and work hours. Four occupational groups were aggregated based on occupation type and occupational skill level: high-skill white-collar, low-skill white-collar, high-skill blue-collar and low-skill blue-collar. Time spent on physical behaviors during workdays (including working hours and leisure time separately) and non-workdays were calculated. Differences in physical behavior compositions were assessed using a compositional data analysis approach based on log-ratios of geometric means, with the low-skill blue-collar group as the reference group. Results: Significant differences in 24-hour physical behaviors across occupational groups were mainly observed during workdays. During workday working hours, all other occupational groups had less physical activity (both moderate-to-vigorous and light-intensity physical activity) compared to the reference group. During workday leisure time, significant differences were observed in all physical behaviors, except for sedentary time. On non-working days, the high-skill white collar group had higher moderate-to-vigorous physical activity compared to the reference group. Conclusions: The composition of domain-specific 24-hour physical behaviors differs across occupational groups, particularly during workdays.

Objectives: Given the high injury burden in football and the documented limitations of strength-based screening, novel approaches are warranted. Adaptive Force (AF)being closer to injury-prone movements than pushing/pulling strength--offers an alternative. This study examined the association between AF-based muscle stability and musculoskeletal complaints in football players and compared AF-derived and conventional strength parameters in their discriminative capacity, complemented by a preliminary prospective follow-up. Methods: AF and maximal voluntary isometric contraction (MVIC) were measured in 23 male football players across five bilateral muscle groups (knee extensors/flexors; hip flexors/adductors/abductors). AF parameters (maximal isometric AF, maximal AF, AF-Ratio), MVIC and hamstrings-to-quadriceps (H:Q) ratio were compared between players with and without complaints assessed via questionnaire at baseline and six-month follow-up (n=13). Results: Stability deficits were strongly associated with complaints (OR=54.0, 82% side concordance). AF-Ratio discriminated clearly between players with and without complaints (d=-1.47), with hip abductors showing the strongest effect (d=-1.64). Players with subsequent complaints showed lower baseline AF-Ratio (d=-1.45) and more stability deficits (d=1.67). MVIC and H:Q ratio did not discriminate (p>0.430). Conclusion: The findings suggest that muscle stability assessment outperforms conventional strength parameters in discriminating players with and without complaints, with preliminary follow-up data providing tentative support for predictive value. The concept of functional instability syndrome (FIS) provides a mechanistic framework for non-contact injuries and musculoskeletal complaints. AF assessment offers potential for screening, including return-to-sport decisions. Further studies are needed to verify the results, investigate predictive value, and evaluate whether personalised stability-based interventions can reduce injury incidence.

Objectives The association between occupational physical activity (OPA) and cardiovascular disease (CVD) may depend on how OPA is classified. This study examined the association between OPA and incident CVD using individual level and occupational group level classifications, and assessed whether factors contributing to attenuation differed. Methods A total of 137,592 employed UK Biobank participants aged 40 to 69 years who were free of CVD at baseline were included. OPA was classified using (i) individual level self reported physical activity at work and (ii) occupational group level two digit Standard Occupational Classification. Associations with incident CVD were examined using Cox proportional hazards models. Attenuation of associations by sociodemographic, lifestyle, health, occupational and psychosocial factors was assessed using univariate adjustments and Heller's coefficient. Results During 1,656,378 person-years of follow up (median 12.6 years), 10,465 incident CVD events occurred. The association between OPA and CVD differed markedly according to exposure classification. High individual level self reported OPA was associated with increased CVD incidence after full adjustment [hazard ratio (HR) 1.19, 95% confidence interval (CI) 1.10 to 1.27]. In contrast, no association was observed when OPA was classified at the occupational-group level using Standard Occupational Classification groupings (HR 1.00, 95% CI 0.94 to 1.06). Sociodemographic and health factors accounted for the greatest attenuation across both classifications, whereas psychosocial factors contributed primarily to associations based on individual-level self-reported OPA. Conclusions The association between occupational physical activity and incident cardiovascular disease differed substantially according to how OPA was classified. These findings highlight exposure classification as a critical consideration when interpreting evidence on the physical activity paradox.

Objective: To examine associations between volume and intensity of leisure time physical activity (LTPA) and fracture risk during midlife and determine whether adherence to World Health Organisation (WHO) physical activity recommendations was associated with fracture risk. Methods: Cross-sectional analysis of UK Biobank participants aged 40 to 65 years using self-reported physical activity and fracture data. LTPA volume (LTPAV) was derived from walking, moderate and vigorous activity. Participants were categorised into LTPAV quintiles and by adherence to WHO physical activity recommendations. Multivariable logistic regression examined associations with self-reported fracture within the previous five years, with sex stratified analyses. Results: Among 322,749 participants, 53% were female with a mean age of 47 years. Fracture risk increased with higher LTPAV, although the association was non-linear and varied by age and sex. The strongest associations were in the highest quintile among men and women aged 40 to 49 years (OR 1.81, 95% CI 1.64 to 1.99 and OR 1.42, 95% CI 1.28 to 1.58 respectively). In mutually adjusted models, vigorous activity demonstrated the strongest independent association with fracture risk. Meeting WHO physical activity recommendations, without exceeding them, was not associated with increased fracture risk. Conclusions: Higher fracture risk was observed in individuals undertaking higher volumes of leisure-time physical activity, with the association largely driven by vigorous-intensity activity. The association was strongest in adults aged 40 to 49 years and in men. Physical activity consistent with current WHO recommendations was not associated with increased fracture risk, supporting continued promotion of physical activity during midlife.

To estimate the life expectancy gains that could be realised from increases in Queenslanders physical activity (PA) levels. Design Lifetable analysis Setting, Participants We modelled the 2025 Queensland population aged [&ge;]40 years. Modelled scenarios We applied two approaches. In the first, we estimated life expectancy differences between device-measured PA quartiles, with quartile1 representing the least active and quartile 4 the most active. In the second, we compared observed device-measured PA levels in Queensland with scenarios in which all individuals moved to either [&ge;]12,000 steps/day or [&le;]2,000 steps/day. We converted the steps per day by age group and PA quartile into equivalent daily minutes of moderate-intensity walking at 4.8 km/h. Additional scenarios were explored in sensitivity analyses. Main outcomes Changes in life expectancy, and total life-years gained over the lifetime of the modelled population. Benefits were also translated into minutes of life gained per additional hour walked. Results If all Queenslanders aged [&ge;]40 years were as active as the most active quartile, life expectancy at birth could be 88.3 years, an increase of 4.8 years above the life expectancy at observed activity levels. The life expectancy differences between individuals in the least active quartile and the most active quartile was 9.7 years. Achieving the activity level of the most active quartile would require individuals in the lowest activity quartile to undertake an additional 85.9 minutes/day of moderate-intensity walking, with each extra hour of PA associated with an average gain of approximately 3 hours (177 minutes) of life. In step-based modelling, life expectancy in the most active scenario (all achieving [&ge;]12,000 steps/day) was higher by {approx}7.1 years compared with the least active scenario (all at [&le;]2,000 steps/day). Conclusions Increasing PA could yield meaningful gains in life expectancy for Queenslanders, with the largest gains seen in least active individuals. Our findings strengthen the case for prioritising investment in PA -promoting programs and environments.

Background. Cardiopulmonary exercise testing (CPET) is a gold-standard test used to evaluate cardiopulmonary fitness and overall health by measuring physiological responses such as oxygen consumption during exercise. While traditional CPET warm-ups are typically low-intensity aerobic activities, alternative methods like coherence breathing may also prepare the body by influencing autonomic regulation. Breathing-based interventions have shown potential to improve heart rate recovery and performance, and heart rate variability (HRV) serves as a useful non-invasive indicator of autonomic nervous system activity. However, there is limited research on how brief breathing exercises before CPET affect outcomes. This study aims to investigate the effects of coherence breathing on oxygen uptake, HRV, and post-exercise heart rate recovery Objective. This study will aim to compare the acute cardiopulmonary and autonomic responses of coherence breathing versus spontaneous breathing immediately preceding cardiopulmonary exercise testing (CPET) in recreationally active healthy adults. Methods. This study will be a randomized counterbalanced crossover design. Healthy adults aged between 19 and 45 years of age will complete two separate CPETs over two non-consecutive test days (between 48 hours and 7days). During each visit, participants will complete five minutes of slow-paced coherence breathing (6 breaths per minute) or spontaneous breathing at normal breathing rate, followed by an incremental treadmill CPET protocol up to maximal exertion. HRV will be assessed at baseline, during the breathing interventions, and during cool-down for 5 minutes using the Emwave Pro Plus software. Gas exchange during the CPET protocol will be measured continuously using the VO2 Master Pro system. immediately after, and after 5 minutes of resting. The primary outcomes will be peak oxygen consumption and heart rate variability indices. Secondary outcomes will include heart rate recovery, peak heart rate, time to exhaustion, rate of perceived exertion and readiness, blood pressure, tidal volume, peak ventilation, and respiration rate. Analyses will use linear mixed-effects models and paired comparisons. Discussion. This protocol will determine whether pre-exercise coherence breathing can improve cardiopulmonary and autonomic nervous system responses to maximal performance. Findings may have practical implications for exercise testing and performance procedures as well as improving our understanding of pre-exercise breathing strategies for priming the autonomic and cardiopulmonary systems.

Introduction: Previous studies suggest that conventional Ashwagandha (Withania somnifera) root extracts may improve physical performance in both athletic and non-athletic populations. However, evidence on sustained-release ashwagandha formulations is lacking. This randomized double-blind, placebo-controlled trial evaluated the safety and efficacy of sustained-release ashwagandha root extract (AshwaSR) 300 mg in improving muscle strength in recreationally active healthy individuals. Methods: Eligible participants aged 25-50 years received AshwaSR 300 mg or placebo capsules once daily for 90 days. Changes in one-repetition maximum (1-RM) bench press, maximal oxygen uptake (VO2max), serum testosterone, creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations, and quality of life (QoL using SF-12 questionnaire) from baseline till study end were evaluated. Results: Of 84 enrolled participants, 83 completed the study (AshwaSR, n=41; Placebo, n=42). Compared with placebo, participants receiving AshwaSR demonstrated significantly greater improvements in muscle strength and cardiorespiratory endurance starting from day 30 (1-RM: 4.69 vs 2.23 kg; VO2max: 9.99 vs 6.64 mL/kg/min; p<0.001), and sustained till day 91 (1-RM: 15.31 vs 7.33 kg; VO2max: 30.56 vs 18.14 mL/kg/min; p<0.001). In the AshwaSR group, total testosterone levels significantly increased from baseline to day 90 among men (mean increase = 121.43 ng/dL; p=0.024); while the improvement in testosterone levels among women was non-significant (13.34 ng/dL; p=0.545) and remained within normal reference ranges. The favorable numerical changes in CK and LDH concentrations were observed in AshwaSR group at the end of the study. AshwaSR group reported significantly improved quality of life at day 91 compared to placebo group (Mental component: 7.72 vs -4.66; p<0.001; Physical component: 5.23 vs -1.91; p<0.001). Reported adverse events in both groups were mild and transient in nature. Conclusion: Three-months supplementation with AshwaSR 300 mg/day was safe and effective in improving muscular strength, cardiorespiratory endurance, and overall wellbeing in recreationally active healthy adults. Clinical Trial Registry of India (CTRI) registration number: CTRI/2025/04/084383

Sedentary behavior promotes chronic low-grade inflammation in adipose tissue, contributing to metabolic dysfunction and insulin resistance. High-intensity interval training (HIIT) is a time-efficient exercise strategy with potent anti-inflammatory and metabolic benefits; however, its effects on adipose tissue inflammatory signaling and microRNA (miRNA) regulation remain incompletely understood. This study investigated the effects of eight weeks of HIIT on inflammatory and epigenetic markers in interscapular white adipose tissue (iWAT) of male Wistar rats. Fourteen rats were randomly assigned to either a sedentary (SED; n = 7) or HIIT (n = 7) group. The HIIT protocol consisted of treadmill running five days per week for eight weeks. Body weight and iWAT mass were assessed, and molecular adaptations were evaluated at multiple regulatory levels using RT-qPCR for mRNA targets (NLRP3, TNF-, PPAR-{gamma}, and IL-10) and miRNAs (miR-21 and miR-30d-5p), while protein levels of NLRP3 and PPAR-{gamma} were assessed using Western blotting. Compared with the SED group, HIIT significantly reduced body weight (p < 0.001) and iWAT mass (p = 0.002). Furthermore, HIIT downregulated the expression of pro-inflammatory mediators, including NLRP3 (gene: p = 0.001; protein: p < 0.001) and TNF- (p = 0.025), while upregulating anti-inflammatory regulators PPAR-{gamma} (gene: p = 0.026; protein: p = 0.020) and IL-10 (p = 0.010). In parallel, inflammation-associated miRNAs, including miR-21 (p = 0.004) and miR-30d-5p (p = 0.002), were markedly downregulated. These coordinated transcriptional, post-transcriptional, and translational adaptations suggest that HIIT attenuates adipose tissue inflammation and promotes a favorable immunometabolic phenotype through integrated molecular and epigenetic mechanisms.