0185 Circadian Rhythm of Rock Climbing Specific Finger Strength

Abstract

Abstract Introduction Circadian rhythm influences various aspects of athletic performance; however, the sport specific effects in rock climbing are not well studied. This study aimed to evaluate circadian changes in finger strength in rock climbers. This may have important implications for timing of training and challenging climbing goals. Methods Participants completed two rounds of finger strength testing on the same day (morning 7-9 am and evening 5-7 pm) consisting of maximal pulls on a polyurethane training block (18 mm flat edge) anchored to a dynamometer (TindeqTM). Participants were cued to keep 4 fingers on without using the thumb and given two attempts on each hand with the highest load recorded each session. Demographic data, climbing experience level, sleep quality (Promis Sleep short form.), and chronotype (Morningness-Eveningness questionnaire) were recorded for secondary outcome analysis. Standard descriptive statistics and paired t-tests were performed to compare the morning and afternoon findings. Results 10 participants completed finger strength testing. There was a significant increase in mean maximum finger strength from morning (M = 35.2 kg, SD = 14.8) to afternoon (M = 40.1 kg, SD = 16.1), t(9) = 4.1, p = .003, with a large effect size (Cohen’s d = 1.3). The mean increase was 5.0 kg with 95% confidence interval of 2.2 kg to 7.7 kg. The morning to afternoon increase in maximal strength remained significant when subdivided by sex (males n = 6, p = .04, 95% CI [0.4kg, 10.0] kg, and females n = 4, p = 0.48, 95% CI [0.1, 9.1] kg). This study lacked sufficient power to detect differences related to other secondary measures. Conclusion Maximum finger strength in rock climbers was greater in the afternoon compared to morning suggesting a circadian rhythm influence. Rock climbers needing peak finger strength may benefit from timing hard climbs in the afternoon rather than early morning. Further study is needed to determine if this finding is seen in larger groups or impacted by sleep quality and chronotype. Support (if any) Training space was supported by Triangle Rock Club, Durham NC.