BACKGROUND:Accurate quantification of mechanical power output is fundamental for performance analysis in road cycling. However, access to power meter data is often limited in research and applied contexts. The aim of the present study was to develop and validate a physics-based framework to estimate power outputs in professional cycling with publicly available data. METHODS:Performance data from professional cyclists who completed the uphill individual time trial to Peyragudes in the 2025 Tour de France were obtained from publicly available sources. Mean power output was estimated using a mechanical model that accounts for gravitational, aerodynamic, and rolling resistance forces, incorporating rider mass, course characteristics, velocity, and altitude-derived air density. Estimated values were compared with power meter data available from riders' publicly shared activity files. RESULTS:The comparison across 28 professional cyclists showed a good level of agreement between estimated and measured power outputs (mean absolute error = 14.07 W; Mean absolute percentage error = 3.65%). The model exhibited a small mean bias of -5.43 W where the model slightly underestimated the reported power. Bland-Altman analysis yielded 95% limits of agreement from -36.27 to 25.41 W with 26 of 28 observations within these limits. CONCLUSIONS:These results demonstrate that cycling power during sustained climbing efforts could be approximated using simple externally observable variables. This approach may represent a useful tool for reconstructing performance when direct power meter data are unavailable in professional cycling.
BACKGROUND:Sleep hygiene strategies (SHS) are practical, evidence-informed recommendations to enhance both the quantity and quality of sleep in athletes. However, little is known about how these strategies could be communicated and implemented in practice. The primary objective of this study is to investigate how different methods of delivering SHS (written vs. verbal) affect sleep hygiene and sleep parameters in athletes. METHODS:The study was a three-arms randomized controlled trial (ClinicalTrials.gov Identifier: NCT07083544) involving track and field athletes competing at the regional or national level (N.=66). Athletes were randomized to either a control group (CON=22), a written SHS group (W-SHS=22), or a verbal SHS group (V-SHS=22). Sleep characteristics were assessed by actigraphy and sleep diary during a ten-day baseline period (T0) and a ten-day intervention period (T1). Six objective sleep parameters and the Sleep Regularity Index were assessed. Participants also completed a training diary and the Sleep Hygiene Index (SHI). RESULTS:No statistical differences were found between and within groups in training and sleep parameters, but SHI scores improved significantly in the intervention groups between T0 and T1, with differences compared to the control group. A non-significant improvement in total sleep time was observed in the intervention groups, primarily due to earlier bedtimes. CONCLUSIONS:While significant differences in objective sleep measures were not observed, the trends suggest that both written and verbal SHS interventions can modestly improve sleep-related behaviors, particularly by encouraging earlier bedtimes and slightly extending total sleep duration.
BACKGROUND:Childhood is a critical period for physical and respiratory development. Although Taekwondo training is known to improve physical fitness, limited evidence exists regarding the effects of training duration on respiratory muscle function and its association with physical fitness in children. METHODS:Sixty-four male Taekwondo practitioners aged 8-10 years were categorized into three groups based on training experience (Gup, N.=20; 1st Poom, N.=29; 2nd Poom, N.=15). Body composition, basic physical fitness, isometric muscle strength, and inspiratory muscle function were assessed. Differences among groups were analyzed using one-way ANOVA. Pearson's correlation coefficients were used to investigate the relationships between respiratory function, basic physical fitness, muscular strength, and total training duration. RESULTS:The 2nd Poom group demonstrated significantly superior performance in basic fitness (grip strength, standing long jump, side-step, and shuttle run) compared to the Gup and/or 1st Poom groups. Regarding respiratory function, only the 2nd Poom group showed significantly higher S-index, peak inspiratory flow (PIF), and energy values compared to the Gup group. Furthermore, significant positive correlations between respiratory function and physical fitness variables were observed exclusively in the 2nd Poom group. Total training duration was positively correlated with S-index, PIF, and energy across all participants. CONCLUSIONS:Longer duration of Taekwondo training in childhood is associated with enhanced basic physical fitness, greater muscle strength, and better respiratory muscle function. These findings suggest that sustained Taekwondo practice may provide sufficient stimulus to promote the co-adaptation of the respiratory and neuromuscular systems.
BACKGROUND:The negative impact of excess adipose tissue on aerobic capacity in endurance athletes is now considered well-established. However, there is a lack of research examining this relationship in team sport athletes. METHODS:Thirty-eight soccer players (mean age 23.60±4.22 years) from a leading Russian Premier League team participated in the study. On the first day of the pre-season training camp, participants underwent skinfold measurements according to the International Society for the Advancement of Kinanthropometry standards and a treadmill test with gas analysis. RESULTS:Correlation analysis showed moderate inverse associations between adiposity markers and VO2-derived outcomes. Higher body fat percentage was associated with lower relative VO2max and vVO2max, while the sum of eight skinfolds showed a similar direction of association. However, after FDR correction, these associations should be interpreted cautiously. In prespecified HC3-robust regression models, each 1 percentage point higher body fat was associated with -1.93 mL·kg-1·min-1 lower relative VO2max and -0.49 km·h-1 lower vVO2max. Each 10 mm higher sum of eight skinfolds was associated with -1.77 mL·kg-1·min-1 lower relative VO2max and -0.38 km·h-1 lower vVO2max. Model performance under leave-one-out cross-validation was limited, indicating weak individual-level predictive accuracy. CONCLUSIONS:Higher adiposity markers were directionally associated with lower relative VO2max and vVO2max in elite adult male soccer players. However, the cross-sectional design, modest sample size, high FDR-adjusted q-values, and limited cross-validated performance indicate that the findings should be interpreted as exploratory group-level associations rather than robust individual-level prediction.
