Background: Short-term (5 min) heart rate variability (HRV) analysis is widely used in assessing autonomic nervous system activity during exercise. While shortening the HRV measurement duration can help improve its application efficiency, its accuracy needs to be verified. This study investigated the agreement between ultra-short-term (UST) HRV (3 or 4 min) and standard 5 min HRV and explored the optimal recording duration under resting and post-exercise conditions. Methods: Fourteen participants exercised on a cycle ergometer at 60% of their maximum peak power. Data were collected during the rest condition (Pre-E) and three post-exercise conditions (Post-E1, Post-E2, and Post-E3), with indicators of the standard deviation (SDNN) of the ultra-short and short-term RR intervals and the root mean square (RMSSD) of the continuous difference between RR intervals. Repeated measures ANOVA, Cohen’s d statistic, Bland–Altman analysis, and interclass correlation coefficients (ICC) assessed the agreement between UST-HRV and ST-HRV. Results: The consistency results of SDNN and RMSSD in resting and post-exercise were different. At the Pre-E, Post-E2, and Post-E3 phases, no statistical differences for SDNN and RMSSD were observed, with ICCs surpassing 0.9, indicating a high level of agreement. However, at Post-E2, there was a significant difference between 3 min RMSSD and 5 min RMSSD (p < 0.05), as well as between 3 min SDNN, 4 min SDNN, and 5 min SDNN (p < 0.05). Furthermore, the limits of agreement were observed to decrease as the time duration increased in Bland–Altman plots. Conclusions: UST-HRV analysis is a reliable substitute for standard 5 min HRV assessment, particularly during resting conditions. For post-exercise measurements, assessing the appropriateness of a 3- or 4 min duration based on the exercise’s length is recommended to ensure accuracy and reliability.

Objective: To examine the effect of target load on the multiple object tracking performance of clay pigeon shooters, and to investigate differences in skill level (professional vs. amateur) and gender in this context. The attentional patterns in clay pigeon shooting differ fundamentally from those in ball sports. It remains unclear whether expert advantages exist in multiple object tracking among clay pigeon shooters, and whether long-term training can eliminate gender-based cognitive differences. Methods: Forty clay pigeon shooters (20 professionals, 20 amateurs; 20 males, 20 females) completed a multiple object tracking task with target loads of 2, 3, 4, 5, and 6. The dependent variable was tracking accuracy. A 2 (group) × 5 (target load) repeated-measures ANOVA was conducted, followed by simple effects analysis. Gender differences were examined using a separate 2 (gender) × 5 (target load) ANOVA. Results: Tracking accuracy decreased as target load increased (main effect of target load: ηp ² = 0.793). No differences were found between professional and amateur shooters when tracking 2 or 3 targets. However, under target loads of 4, 5, and 6, professionals showed higher tracking accuracy than amateurs (group × target load interaction: ηp ² = 0.095; simple effects: p = 0.003, 0.005, and 0.014, respectively). No differences were observed between male and female athletes under any target load condition (main effect of gender: ηp ² = 0.055, p = 0.145; gender × target load interaction: ηp ² = 0.024, p = 0.431). Conclusion: Clay pigeon shooters exhibit an expert advantage under high target loads in multiple object tracking tasks. This advantage may reflect domain-general cognitive resources such as working memory updating, attentional reorienting, and inhibitory control, rather than sport-specific multiple-object attentional capacity. No performance differences were observed between male and female athletes, suggesting that long-term intensive training may eliminate the gender gap in spatial attention commonly found in the general population. High-load multiple object tracking tasks may serve as a cognitive diagnostic tool for athlete selection in clay pigeon shooting.