Impact of Time of Day and Gender on Power Output in Division I Athletes

Authors

Nicholas Urias, Grand Canyon UniversityFollow
Kennedy Krebs, Grand Canyon UniversityFollow
Dalton Lesser, Grand Canyon UniversityFollow
Zachary Farrel
Zachary Zeigler, Grand Canyon UniversityFollow

Abstract

Power is increased in the afternoon compared to the morning. Whether this impact is similar for both sexes is not clear. PURPOSE: The purpose of this study is to determine if there is an interaction between sex and time of day on power. METHODS: 223 Men and 216 women division 1 athletes from soccer, volleyball, baseball, track and field, tennis, basketball, and cross country were tested. Athletes were asked to complete counter movement jumps, multiple times on a force plate (VALD) throughout the academic year. Dependent variables were jump height, relative peak power (RPP), absolute peak power (APP), and reactive strength index (RSI). Data was analyzed using two-way ANOVA using time and gender as main effects and then to determine if there was a time*gender interaction. RESULTS: For males, 5,191 jumps occurred before noon, while 1,563 were after noon. Jump ht. (39.8±6.3 vs. 44.4±7.3 cm, ƞ2=.079, p<.001), RPP (60.0±9.5 vs. 64.5 ±8.9 W/kg, ƞ2=.039, p<.001), APP (5073.4±1027.3 vs. 5174.3±883.3 W, ƞ2=.002, p<.001) and RSI were higher in the afternoon. There was no statistical difference for RSI (p=.306). For females, 3,621 jumps were before noon, 3,434 were after noon. Jump height (28.4±5.3 vs. 32.7±5.6 cm, ƞ2=.136, p<.001), RPP (45.5 ±6.3 vs. 50.1±6.6 W/kg, ƞ2=.111, p<.001), APP (3158.3±586.1 vs. 3379.5±450 W, ƞ2=.043, p<.001), and RSI (.668±.10 vs. .730±.12 m/s, ƞ2=.066 p<.001) were all increased in the afternoon hours. There was no significant interaction between gender and time of day for jump ht. (p=.346), RPP. There was an interaction for APP (p < .001) such that females increased more than males in the afternoon. CONCLUSION: Time of day should be considered when conducting performance testing to account for potential variations in results. Further research is needed to investigate why females demonstrated a larger increase in APP.

Recommended Citation

Urias, Nicholas; Krebs, Kennedy; Lesser, Dalton; Farrel, Zachary; and Zeigler, Zachary (2024) "Impact of Time of Day and Gender on Power Output in Division I Athletes," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 4, Article 103.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss4/103