Abstract
This study aimed to assess the impact of 6mg/kg of caffeine (CAFF) on running performance and technique. Using a randomized, double-blind, crossover structure, 14 subjects ran 2.5 kilometres on a treadmill, without (PRE) and with (POST) fatigue, under 3 conditions with 7 days as a wash-out: control (CON), placebo (PLA), and CAFF. CON was always assessed first. The results showed that POST, there was less flight time (d = 0.85), more step rate (d = 0.61-0.62) and less stride length in both legs (d = 0.61-0.63), less knee flexion (d = 0.75), and a slower performance (d = 0.72). Compared to CON, PLA increased contact time in both legs (d = 0.70-1.01) while improving performance (d = 1.00), and CAFF reduced step rate (d = 0.85-0.86) and increased stride length in both legs (d = 0.82-0.86) while also enhancing performance (d = 1.01). CAFF PRE showed a faster time compared to CAFF POST, PLA POST, CON PRE, and CON POST (d = 1.17-1.92), and PLA PRE was faster than CON PRE, CON POST, and CAFF POST (d = 1.19-1.50). In conclusion, CAFF improved running performance compared to CON, suggesting a front-loaded strategy, while PLA also enhanced performance relative to CON. Furthermore, CAFF, PLA, and fatigue modified running kinematics. This trial was prospectively registered on Clinical Trials (NCT06039358; September 2023) and supported by "AGAUR-FI ajuts".
Description
Caffeine improved running performance and modified kinematics in a randomized crossover trial.