The effect of caffeine on lower body resistance exercise in resistance-trained women

Abstract

Background Research demonstrating the effect of caffeine to enhance lower body resistance performance is conflicting. The majority of research have recruited male participants, due to the altered clearance of caffeine during phases of menstruation in women. Therefore, the purpose of this study is to provide further insight into the ergogenic effect of acute caffeine ingestion on lower-body muscular endurance, strength and power in resistance-trained women. Methods A double-blind, randomised crossover design was adopted, whereby 23 women consumed caffeine (6mg/kg) or placebo approximately 28 days apart. Sixty minutes post supplementation ingestion, participants performed a counter-movement jump test, a one-repetition maximum (1RM) leg press and repetitions to failure at 60% of the 1RM. Heart rate (HR), blood pressure (BP) and ratings of perceived exertion were recorded immediately following each exercise test. Results Paired t-test results indicate no significant differences between trials for the 1RM leg press (p = 0.10), 60% of the 1RM leg press to failure (p = 0.83) and the counter-movement jump (p = 0.94). Changes in HR indicated a significant effect of time (time: F1,22 = 130.24, p < 0.01), but not of condition (p = 0.11) or interaction (0.50). Significant changes in BP between conditions were determined for the effect of time for systolic (p < 0.01) and diastolic BP (p < 0.01), but not for the effect of condition or interaction. Conclusion Acute supplementation of caffeine has no effect on lower body muscular strength, endurance and power in resistance trained women.

Date of Award	2020
Original language	English
Supervisor	Oliver Peacock (Supervisor)