European journal of sport science最新文献

In previous research, physiological resilience has been measured as deterioration of the physiological profile during prolonged exercise. This study aimed to evaluate the test-retest reliability of physiological resilience during prolonged moderate-intensity running. Physiological profile of 26 well-trained endurance runners (10 females) was tested in nonfatigued state as well as during and after two identical ∼2.5-h long physiological resilience tests at ∼89% of VT1 (ventilatory threshold 1) speed within an average period of 13 days. Reliability was assessed with intraclass correlation coefficients (ICC), coefficient of variations (CV%), and typical errors (TE and TE%). Change in maximal speed achieved in the incremental test (sPeak) was the most reliable metric and showed good reliability (ICC: 0.81 and TE: 1.8). The drifts in running economy (RE) and the heart rate (HR) had moderate to good reliability in the second half of the trial (ICC: 0.52-0.80 and TE 1.7-2.4). The changes in maximal oxygen uptake (VO_2max) and ventilatory thresholds (VTs) had poor reliability (ICC: 0.07-0.36 and TE: 3.5-4.6). However, the absolute values of these variables demonstrated good to excellent reliability in fatigued state (ICC > 0.83, TE% < 5.2%, and CV% < 4.1%) even though they significantly deteriorated. Determining changes in sPeak and drifts in RE and HR appears to be the most reliable method to measure physiological resilience. In contrast, measurement of the physiological profile remains reliable in fatigued state for every variable. Longer or more demanding protocols may be required to obtain greater reliability for deterioration of the physiological profile.

This randomized controlled trial examined the effects of a 10-week high-intensity interval training (HIIT) program on physiological and hematological outcomes in 28 adolescent girls with overweight or obesity. Participants were randomly assigned to a HIIT group or a control group. The HIIT protocol comprised 4 sets of 6 × 15-s bouts at 90%-105% of maximal aerobic speed (MAS), interspersed with 15-s active recovery at 50% MAS, performed three times per week. Significant group×time interactions were observed for body composition, aerobic capacity, maximal heart rate (HRmax), erythrocytes, hemoglobin, hematocrit, creatine kinase (CK), and lactate dehydrogenase (LDH). Between-group comparisons showed greater improvements in body mass, body fat, waist circumference, MAS, estimated VO₂max, and plasma volume in the HIIT group compared with controls, though not all differences reached statistical significance. Within-group analysis in the HIIT group revealed reductions in body mass (p < 0.001, d = 0.37), body fat (p = 0.001, d = 0.78), waist circumference (p < 0.001, d = 0.54), HRmax (p = 0.020, d = 0.88), erythrocytes (p = 0.007, d = 0.46), hemoglobin (p = 0.019, d = 0.84), hematocrit (p = 0.004, d = 0.34), CK (p = 0.049, d = 0.29), and LDH (p = 0.032, d = 0.41), alongside increases in MAS (p = 0.007, d = 0.64) and estimated VO₂max (p = 0.007, d = 0.64). Plasma volume variation was also higher in the HIIT group. Overall, a 10-week HIIT intervention enhanced body composition, plasma volume, and cardiorespiratory fitness, while reducing markers of muscular and metabolic stress. These results indicate that HIIT is a feasible and effective approach for improving physiological and metabolic health in adolescent girls with overweight or obesity, supporting its potential as a targeted exercise strategy in this population.

Previous research indicates high concussion knowledge is not associated with better concussion reporting, with research examining the relationship between reporting and global concussion knowledge. Concussion knowledge has not yet been investigated in United States Major League Rugby (MLR) players. This study evaluated domain-specific concussion knowledge, concussion history, and reporting behaviors among active MLR players. In a cross-sectional design, 207 MLR athletes (age 26.6 ± 3.4 years) completed a survey assessing concussion history, knowledge, and nondisclosure reasons. While in the MLR, 24% reported an undisclosed concussion, with nondisclosure reasons related to a lack of concussion knowledge, a desire to continue playing, or not wanting to let the coach and/or team down. Significant positive correlations between concussion knowledge statements indicated three concussion knowledge domains: Immediate Management, Potential Post-Concussion Consequences, and Concussion Recognition. MLR players demonstrated the least knowledge in the Concussion Recognition domain and the greatest knowledge in the Potential Post-Concussion Consequences domain. Athletes with more reported concussions (across measures) or ding/bell rung instances were more likely to correctly disagree with false statements about concussions (r_s range -0.153 to r_s = -0.371), particularly in the concussion recognition domain. Understanding gaps in specific concussion knowledge domains and how those gaps influence concussion reporting could inform more targeted concussion education and potentially improve concussion reporting where nondisclosure is due to concussion knowledge misconceptions. Future research should explore domain-specific concussion knowledge in diverse athletic populations.

This study aimed to analyze potential menstrual cycle-related changes in physical parameters associated with performance and injury risk, focusing on neuromuscular control and motor performance in physically active young females. Twenty-two healthy participants with regular menstrual cycles (24–34 days) were examined sequentially during the follicular phase (day 3), ovulatory phase (within 48 h after a positive urine LH test), and luteal phase (7 days post-ovulation). Ovulation was indicated by a positive urinary LH surge test. The assessments included countermovement jump (CMJ), squat jump (SJ), postural control, ankle dorsiflexion range of motion (ROM), and isokinetic concentric maximal strength. Statistical analyses involved one-way repeated-measures ANOVA or the Friedman test for non-normally distributed data. Significant effects across the menstrual cycle were found for maximum concentric flexion strength (p = 0.003; $$ = 0.037) and ankle ROM (p = 0.043; $$ = 0.010). Post hoc analysis revealed a significant increase in concentric flexion strength from the follicular to the luteal phase (p = 0.004), whereas no significant pairwise differences were observed for ankle ROM. Concentric flexion strength increased significantly from the follicular to the luteal phase (+7.4%), and ankle ROM showed a trend toward improvement, with the highest values observed in the luteal phase (+3.8%). In contrast, CMJ, SJ, and postural control remained constant across all phases. Overall, neuromuscular and motor performance parameters appear largely consistent throughout the menstrual cycle, with only small fluctuations in strength and flexibility. These findings suggest that menstrual cycle-related changes have limited functional relevance but may still warrant consideration in future studies investigating individual responses and injury risk.

This study aimed to compare the accuracy of machine learning classification for three commonly prescribed shoulder exercises in people with and without rotator cuff tendinopathy. Eighteen participants with rotator cuff tendinopathy (mean age 54.2, SD 13.2; 50% female), followed by eighteen matched controls completed a laboratory-based shoulder strength testing protocol. Three exercises were performed (shoulder press, lateral raise and bent over row) while wearing three inertial measurement (IMU) sensors (Axivity, Ax6 - 3 axis accelerometry and gyroscope at 100 Hz and 1000°/sec respectively) positioned on the wrist arm and trunk. Data were analysed and accuracy was compared between common machine learning algorithms for those with rotator cuff tendinopathy and healthy matched controls in a subject-dependent and subject-independent model. The best accuracy scores for the subject-dependent results were achieved by a random forest algorithm; 96.12% (3-sensor combined system) for those with rotator cuff tendinopathy. For the subject-independent results best accuracy scores were achieved by a convolutional neural network algorithm; 94.55% (3-sensors) for the healthy controls without shoulder pain. K-fold cross validation confusion matrix results by exercise type for the entire cohort show 97% accuracy (shoulder press), 95.5% (lateral raise) and 90.7% (bent over row) (3-sensors, CNN subject-independent analysis). Machine learning classification of 3 different shoulder exercises in people with rotator cuff tendinopathy and matched healthy controls demonstrate most accurate results using a CNN algorithm for subject-independent analysis and a RF algorithm for subject-dependent analysis. Results were similar for both those with rotator cuff tendinopathy and their matched healthy controls.

School is widely recognized as one of the primary sources of stress among adolescents. While some studies employing laboratory-based stressors have suggested that adolescents with better cardiorespiratory fitness (CRF) may exhibit lower stress reactivity to psychosocial stressors, research based on real-life stressors is lacking. Therefore, we examined whether CRF predicts physiological and psychological reactivity in response to a real-life stressor (mathematics exam). Students were recruited from Swiss public schools (9th grade). The final sample included 67 students (58% female, Mage = 15.09 years). Heart rate (HR), heart rate variability (HRV), mood states, and state anxiety were used as indicators stress reactivity. CRF was assessed using the 20m shuttle-run test. Statistical analyses used regression analyses, which were controlled for relevant social and demographic confounders, as well as baseline outcomes during a nonstress condition (normal mathematics lesson). Exposure to the mathematics exam resulted in decreased HRV and mood, alongside increased state anxiety. While better CRF was associated with lower HR, higher HRV, better mood, and lower state anxiety across stress and baseline conditions, CRF did not predict physiological and psychological outcomes after controlling for baseline scores and confounders. Hence, our study suggests that although better CRF is associated with favorable physiological and psychological states, this relationship appears independent of students' current stress exposure. Further research employing other ecologically valid stressors is needed to better understand the impact of CRF on real-life stress reactivity. From a school health perspective, it is essential to support students in developing the capacity to cope effectively with academic stressors.

This study aimed to determine whether fat metabolism differs between males and females when exposed to extreme exercise-heat stress. Physically active males (n = 11, 23 ± 4 years, 81.7 ± 11.8 kg, body fat 16.4 ± 6.6%) and females (n = 13, 25 ± 4 years, 60.4 ± 7.1 kg, 24.4 ± 6.7%) completed a 2-h exercise-heat tolerance test (40$$C, 40% relative humidity). Differences (pre-, post-, change, and mean difference (MD)) within and between groups were analyzed. The subcutaneous abdominal adipose tissue (SCAAT) interstitial glycerol concentration and adipose tissue blood flow (ethanol Output:Input (O:I)) pre-exercise, every 30 min (min) of exercise, and during recovery was measured with microdialysis. Non-esterified fatty acids, insulin, insulin-like growth factor, epinephrine and norepinephrine, and cortisol were measured in blood. Resting energy expenditure (REE) was measured pre- and post-exercise and exercising metabolic heat production (MHP) was collected during 30 and 90 min of the HTT. Despite no sex differences in systemic blood biomarkers, fat oxidation (g × min⁻¹) was higher in males (M) (vs. Females (F)) at 30 min of HTT (3.92 ± 0.25 (M), 3.58 ± 0.38 (F), p = 0.021). SCAAT interstitial glycerol was similar across all time points between sexes (baseline glycerol ranges (mmol × L⁻¹): 104.6–1260.0 (F), 165.0–775.6 (M)); however, females had a greater O:I ratio at 90 min of exercise (vs. M) (0.69 ± 0.33 (F); 0.44 ± 0.20 (M); p = 0.033). Pre- and post-exercise REE were 23% (MD: 447.5 kcal × day⁻¹, p < 0.001) and 25% (MD: 485 kcal × day⁻¹, p < 0.001) lower in females compared to males. Post-exercise RER (0.67 ± 0.06 (F); 0.72 ± 0.08 (M); p = 0.045) and mean MHP was higher in males (MD: 94W). Fat oxidation was higher in males compared to females at 30 min with no changes in SCAAT lipolysis or blood biomarkers before or after an acute bout of exercise-heat stress.

This study assessed general and more detailed post-activation performance enhancement responses to cluster sets (CS) + accentuated eccentric loading (AEL) versus a traditional method (TRD) in vertical jump performance and strategy. Six men and six women completed lower-body complex training: countermovement jump was performed at baseline and 1-, 2-, 4-, and 6-min after back squat using CS + AEL and TRD in a randomized crossover manner. CS + AEL used 20 s of inter-repetition rests for back squat and 30% body mass dumbbells for countermovement jump (on the first repetition only across three repetitions at 2-, 4-, and 6-min post), unlike TRD. Data were analyzed as: condition × time (1-, 2-, 4-, and 6-min) and condition × time (2-, 4-, and 6-min) × rep (1, 2, and 3), with baseline as a covariate. Peak power was significantly (p < 0.05) decreased during CS + AEL at 4-min (g = −0.73) and increased during TRD at 2-min (g = 0.46) compared to respective baseline. Peak power was significantly reduced during CS + AEL at 4-min on rep 2 (g = −0.85) and 3 (g = −1.28) and elevated during TRD at 2-min on rep 3 (g = 0.72) compared to respective rep 1. Despite a significant interaction for concentric duration, none of the repetitions were statistically different compared to respective rep 1. CS + AEL compromised post-activation performance enhancement at 4-min post, potentially due to rep-to-rep decreases in peak power on rep 2 and 3, unlike TRD.