TIME-OF-DAY EFFECT ON ISOKINETIC PEAK TORQUE DURING KNEE FLEXION AND EXTENSION
University of Puget Sound, Tacoma, WA
The effects of circadian rhythms on exercise have been well documented using tests such as the Wingate, jumping, sprinting, and weight lifting, but little research has been conducted during isokinetic exercise. PURPOSE: The purpose of this study was to examine how isokinetic peak torque of the knee extensors changes throughout the day. METHODS: Twenty-five apparently healthy, college aged recreational athletes (defined as never having participated in NCAA athletics or having concluded their participation in NCAA athletics) (age 20.68 ± 0.85 yrs, height 172.44 ± 5.50 cm, and weight 69.93 ± 9.22 kg) with no history of injury to the right knee or diagnosed sleeping problems completed one familiarization and three experimental sessions, with start times of 08:00-09:00, 13:00-14:00, and 18:00-19:00. Subjects performed three sets of four maximal discrete knee extensions at 60, 180, and 300˚/second, with one minute of passive rest between each velocity set. Peak torque was recorded for each velocity. Data were analyzed using a two-way 3 (time) x 3 (velocity) repeated measures ANOVA (α ≤ .05). RESULTS: There was no significant difference in peak torque by time of day at any of the three velocities (F = 0.258, p = 0.773). CONCLUSION: This result indicates that time of day may not be a necessary factor to control when creating rehabilitation or training protocols for college-aged subjects undergoing isokinetic exercise involving knee extension.
"TIME-OF-DAY EFFECT ON ISOKINETIC PEAK TORQUE DURING KNEE FLEXION AND EXTENSION,"
International Journal of Exercise Science: Conference Proceedings: Vol. 8:
4, Article 53.
Available at: https://digitalcommons.wku.edu/ijesab/vol8/iss4/53