Physiologia

Background/Objectives: Despite increasing interest in high-intensity exercise and cerebrovascular function, the effects of maximal sprint exercise on cerebrovascular reactivity (CVR), a key indicator of vascular health, remain unclear. Methods: This study investigated the acute effects of a 30-s all-out cycling sprint (Wingate Anaerobic Test, WAnT), on CVR to hypocapnia in 24 healthy young adults (12 males). Following familiarisation and a $\dot{\mathrm{V}}$O_2max test, participants completed an experimental session where CVR was assessed at rest and 30 min post-WAnT. CVR was evaluated using a 1-min voluntary hyperventilation protocol (25 breaths·min⁻¹), with middle cerebral artery blood velocity (MCAv) measured via transcranial Doppler ultrasound and end-tidal CO₂ (P_ETCO₂) recorded breath-by-breath. CVR was calculated as the absolute change in MCAv per 1 mmHg change in P_ETCO₂ from the final 10 s of hyperventilation. Results: Resting MCAv and P_ETCO₂ were significantly reduced post-WAnT (p < 0.01 and p < 0.001 respectively). Consequently, the reductions in MCAv and P_ETCO₂ during hyperventilation were attenuated after exercise in both males and females (p < 0.01 and p < 0.001 respectively). Despite these changes, CVR remained unaltered in both sexes following WAnT (males: 1.79 ± 0.35 vs. 1.59 ± 0.26 cm·s⁻¹·mmHg⁻¹, p = 0.09; females: 2.01 ± 0.44 vs. 2.01 ± 0.46 cm·s⁻¹·mmHg⁻¹, p = 0.97). However, post-exercise CVR was significantly lower in males than females, despite no baseline sex differences (p = 0.01). Conclusions: Cerebrovascular reactivity to hypocapnia is preserved 30 min after a single bout of maximal sprint exercise in healthy young adults. Notably, females demonstrated a more favorable maintenance of CVR post-exercise compared to males, suggesting potential sex differences in CVR following maximal sprint exercise.

Background: Anthropometric characteristics are known determinants of rowing performance, particularly during adolescence, when rapid physical growth affects strength, leverage, and movement efficiency. Understanding how body size and proportionality relate to rowing output is essential for contextualizing performance differences during youth rowing development. Objective: This study examined the associations between anthropometric variables and 2000 m ergometer performance in a multinational cohort of adolescent rowers, with separate analyses for males and females. Methods: A total of 126 youth rowers (65 males, 61 females) aged 14–16 years from eight countries participated. Standardized anthropometric measurements including body height, body mass, body fat (F%), relative muscle mass (M%), limb lengths, and body surface area (BSA) were assessed. Performance was assessed via maximal 2000 m ergometer testing, recording mean power output (W). Results: Significant anthropometric differences were observed between sexes. Performance outcomes mirrored these patterns: males produced substantially greater ergometer power (327.10 ± 48.65 W) compared to females (219.63 ± 30.96 W, p = 0.015). Across nations, anthropometric and performance means differed numerically but showed no statistically significant between-country differences (p > 0.05), despite small-to-moderate effect sizes. Correlation analyses revealed strong positive associations between ergometer power and body height (males: r = 0.70; females: r = 0.71), body mass (males: r = 0.75; females: r = 0.70), relative muscle mass (males: r = 0.62; females: r = 0.64) and body surface area (males: r = 0.78; females: r = 0.73). Relative fat mass showed a moderate-to-strong negative association with performance (males: r = −0.67; females: r = −0.64; p < 0.01). Conclusions: Anthropometric variables—particularly height, body mass, muscle mass, and body surface area—are strongly associated with rowing ergometer performance in adolescent athletes. These findings underscore the relevance of morphological profiling in youth rowing and provide descriptive insight into anthropometric–performance relationships during early junior rowing.

Background/Objectives: Competitive karting places high physiological and cognitive demands on drivers. This field study investigated the acute effects of racing on heart rate variability (HRV), perceived fatigue and neuromuscular function, and cognitive-motor performance during an official event held under persistent rain. Methods: Longitudinal, repeated-measures design across two conditions: control (race video viewing) and competition (qualifying and race). Four drivers (Junior, X30 Senior, X30 Super Shifter) were assessed pre/post-control and post-qualifying/race on Day 1 (Saturday) and pre/post-race only on Day 2 (Sunday). Measures included continuous heart rate, pre/post HRV (HRV4Training; rMSSD, SDNN), perceived fatigue (ROF), bilateral handgrip strength, and visuomotor performance (reaction times and accuracy). Results: On Day 1, SDNN and rMSSD decreased significantly after qualifying versus pre- and post-control (p < 0.05), remaining globally lower post-race; no changes emerged in frequency-domain indexes. Perceived fatigue, handgrip strength, and mean/max reaction times did not change significantly; an improvement in minimum reaction time was observed post-race versus post-control (p = 0.033). rMSSD consistently decreased after racing on both days (p < 0.05) with no day × time interaction observed, and accuracy improved on Sunday, reflected by more correct attempts (hits) and fewer failed attempts (errors) (p < 0.05). Conclusions: Racing was associated with lower time-domain HRV indices (rMSSD/SDNN), consistent with heightened autonomic activation without measurable decrements in handgrip-based neuromuscular function or cognitive-motor performance. The improved accuracy on Day 2 may be related to an increased level of physiological activation and readiness associated with race day. Routine HRV monitoring across race weekends is recommended to guide recovery decisions when subjective scales show limited immediate sensitivity. These findings are preliminary due to the small and heterogeneous sample and should be interpreted cautiously.