Physiologia

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.

Background/Objectives: The correlation between in vivo morphological and functional changes in the degenerating retina in a large animal model of retinitis pigmentosa (RP) has not been characterized longitudinally. Herein, spectral domain optical coherence tomography (SD-OCT) was used to monitor the dynamic morphological changes in the Pro23His rhodopsin transgenic (TgP23H) pig model of RP and was correlated with electroretinography (ERG) in the rapid, early phase of photoreceptor degeneration. Methods: TgP23H and wild-type (WT) hybrid pig littermates at the ages of postnatal days 30 (P30), P60, and P90 were studied. The thickness of different retinal layers was quantified using SD-OCT and compared with histology. Retinal function was evaluated with ERG at corresponding time points. Results: In the WT pigs, retinal morphology on SD-OCT was consistent throughout the observation period. In the TgP23H pigs, the retinal thickness decreased significantly from P30 to P90. Moreover, the relative intensity of the ellipsoid zone (EZ) progressively decreased, while the intensity of the interdigitation zone–retinal pigment epithelium (IZ-RPE) progressively increased during this period. Morphological changes in SD-OCT corresponded with histology, as well as the progressively decreased amplitude of the ERG photopic a- and b-waves in the TgP23H pigs. Conclusions: Retinal degeneration can be quantified using SD-OCT by measuring retinal thickness and the intensity of the EZ and IZ-RPE bands in the TgP23H pig. The SD-OCT results correspond with the histologic and ERG assessments of retinal degeneration. These data provide a foundation for future preclinical studies investigating potential new therapeutic strategies in a large animal model of retinitis pigmentosa.