ABSTRACT Runners increasingly train and compete in warm conditions, yet it is unclear whether heat stress accelerates the deterioration of the physiological determinants of distance‐running performance during prolonged running. Ten trained runners (7 M; 3 F; 38 ± 11 years; peak oxygen uptake (V̇O 2 peak): 56.0 ± 5.7 mL·kg −1 ·min −1 ) visited the laboratory on four occasions. In randomized order, participants completed incremental tests to determine the first ventilatory threshold (VT 1 ), V̇O 2 peak, and end‐test speed in temperate (TEMP; 19°C) and warm (WARM; 30°C; both 40% relative humidity) conditions in a “fresh” state (PRE). Tests were repeated (POST) after 90 min of running in the same condition at 5% Δ between the speed at VT 1 (sVT 1 ) and end‐test speed. Running economy was measured at 15‐min intervals throughout. In the rested state, sVT 1 was ~7% (~0.8 km·h −1 ) lower in WARM than TEMP, and declined after prolonged running in both conditions (TEMP: −8.6%; WARM: −11.1%), with no condition × time interaction. V̇O 2 peak was reduced after prolonged running (TEMP: −4.8%; WARM: −4.0%), with no condition × time interaction. In contrast, running economy deteriorated to a greater extent in WARM (+5.4% vs. +1.7% from 15 to 90 min), and end‐test speed declined more in WARM than TEMP (−12.1% vs. −6.8%). We found no evidence that heat altered the durability of sVT 1 and V̇O 2 peak when intensity was prescribed relative to condition‐specific capacity. However, sVT 1 was already lower in WARM before prolonged running, so that after prolonged running it was, on average, 17.1% below the rested value in TEMP.
ABSTRACT We investigated whether 14 weeks of multicomponent training delivered as small‐sided soccer improves body composition, cardiorespiratory fitness, and metabolic outcomes in adults with type 2 diabetes. Adults aged 40–70 years ( n = 111) were randomized to exercise ( n = 66; three 60‐min sessions per week) or usual care ( n = 45). Constrained linear mixed models estimated between‐group differences in change. No between‐group difference was detected in the primary outcome, lean body mass (0.04 kg, 95% CI −0.97 to 1.05), or in fat mass, body fat percentage, or HbA1c. Compared with usual care, exercise produced greater increases in relative VO 2peak (between‐group difference: 2.80 mL·kg −1 ·min −1 , 95% CI 1.69 to 3.92), absolute VO 2peak (237 mL/min, 95% CI 143 to 331), and Yo–Yo Intermittent Endurance Level 1 test performance (122 m, 95% CI 12 to 232). Exploratory analyses showed lower C‐peptide (−10.3%, 95% CI −19.0 to −0.6) and HOMA2‐IR (−10.8%, 95% CI −20.1 to −0.6), and higher HOMA2‐%S (+12.2%, 95% CI 0.6 to 25.1), in the exercise group relative to usual care. Exploratory three‐way interaction tests provided no clear evidence that glucagon‐like peptide‐1 receptor agonist (GLP‐1RA) use modified the effects on lean body mass, fat mass, or absolute VO 2peak . Small‐sided soccer improved cardiorespiratory fitness, whereas a benefit for lean body mass was not demonstrated. The metabolic findings require confirmation. Trial Registration: ClinicalTrials.gov identifier: NCT06478173
ABSTRACT High‐intensity interval training (HIIT) is widely used in team sports, but the influence of participant and programme characteristics on physiological adaptations remains unclear. Five databases (Web of Science Core Collection, PubMed, Embase, Scopus, and CNKI) were searched initially on 25 April 2025 and updated on 21 December 2025. Mixed‐effects models were used to estimate Hedges' g and 95% confidence intervals (CI). Forty‐six studies involving 1204 athletes were included. Compared with regular sport‐specific training alone, HIIT produced positive effects on maximal oxygen uptake (VO 2 max; g = 0.76, 95% CI [0.61, 0.92]), maximal aerobic power ( g = 0.43, 95% CI [0.04, 0.82]), ventilatory threshold ( g = 0.70, 95% CI [0.53, 0.88]), Yo‐Yo intermittent recovery test performance ( g = 1.02, 95% CI [0.76, 1.28]), and 30‐s Wingate peak ( g = 0.91, 95% CI [0.67, 1.16]) and mean power ( g = 0.70, 95% CI [0.39, 1.01]). Effects on body composition were generally unclear. Mutually adjusted multivariable meta‐regression identified no convincing evidence of differences in VO 2 max or Yo‐Yo intermittent recovery test performance effects by sex or training level. Longer training duration was associated with greater VO 2 max effects. In exploratory analyses, model predictions indicated increases in VO 2 max of 2.56 mL·kg −1 ·min −1 (95% CI [1.54, 3.58]) after approximately 5 weeks and 5.11 mL·kg −1 ·min −1 (95% CI [3.32, 6.91]) after approximately 10 weeks. Shorter between‐repetition recovery was associated with greater VO 2 max effects, although other programme variables were estimated imprecisely. Overall, adding HIIT to regular sport‐specific training improves aerobic and anaerobic performance in trained team‐sport athletes, whereas effects on body composition are limited. Associations involving programme characteristics should be interpreted cautiously because they were derived from study‐level meta‐regression. Trial Registration: PROSPERO Registration CRD42024609379
ABSTRACT This study aimed to develop an interpretable machine learning framework using plantar‐pressure sensors to estimate knee moments during rugby‐specific movements. A total of 31 North American competitive rugby players were recruited to perform four common rugby movements on an infilled artificial turf surface in a motion capture laboratory. Synchronized data acquisition was performed for plantar pressure, motion capture, and ground reaction forces. Knee moments were calculated via inverse dynamics. Genetic Algorithm‐Deep Forest Regression (GA‐DFR) was used to select plantar‐pressure sensors and predict resultant moments within participant‐level nested cross‐validation. Four alternative models predicted the resultant using the same layouts and participant splits. Complementary deep forest regression (DFR) models predicted the three moment components using these layouts. SHapley Additive exPlanations (SHAP) interpreted held‐out predictions. Layouts contained 7–18 sensors. Pooled resultant R 2 was 0.795, with root mean square error of 0.0512 N·m/N. DFR performed better than linear regression and the convolutional neural network, with no significant differences from the deep neural network or long short‐term memory network. Pooled R 2 was 0.806, 0.662, and 0.675 for flexion‐extension, adduction‐abduction, and internal‐external rotation moments, respectively. Resultant temporal SHAP contributions exceeded their stance‐wide mean during 9%–55% of stance, peaking at 24%. Reduced plantar‐pressure inputs supported estimation of resultant and direction‐specific knee‐moment waveforms in unseen rugby players.
ABSTRACT The joint position at which maximal torque is produced indicates the optimal position for agonist muscles to function. It is well‐documented that the maximal voluntary isometric contraction (MVIC) torque of ankle plantar‐flexion varies with knee and ankle joint positions. However, metatarsophalangeal (MTP) joint position may also affect MVIC torque, reflecting force–length relationships of the toe flexor muscles. This study examined the effect of MTP joint position on MVIC torque of ankle plantar‐flexion. Sixteen young males performed MVICs of ankle plantar‐flexion with the MTP joint at 0°, 15°, 30°, and 45° of dorsiflexion. Ankle plantar‐flexion torque, plantar pressure distribution, and surface electromyography (sEMG) were recorded. MVIC torque was significantly greater at 15° than at 0°, 30°, and 45° (+11.0%–21.4%). Similarly, forces applied under the toes were significantly greater at 15° than at the other conditions (+13.4%–37.5%), whereas forces applied under the proximal foot and sEMG amplitudes of the major ankle plantar‐flexors remained comparable across MTP joint positions. At 45° MTP joint dorsiflexion, toe forces were 17.5% lower than at 30°, COP shifted 3–5 mm proximally, and sEMG amplitudes were 26.8% lower in abductor hallucis than at 30°, and 28.9% and 26.3% lower in flexor digitorum brevis than at 15° and 30°, respectively. These results demonstrate that MVIC torque of ankle plantar‐flexion varies with MTP joint position in an inverted U‐shaped manner and is maximized at 15° of MTP joint dorsiflexion, reflecting changes in toe flexor forces, proximodistal COP displacement, and sEMG amplitudes of the intrinsic foot muscles.
