An extract from whole Coffea arabica coffee cherry improves time trial performance, but not muscle glycogen...

This study aimed to test the hypothesis that a whole Coffea arabica coffee cherry extract concentrated in caffeine and polyphenols would increase exercise performance and muscle glycogen resynthesis.

Twelve trained cyclists (11 male, 1 female; V̇O_2max: 55 ± 2 mL·kg^-1·min^-1) took part in a double blind, randomized, placebo-controlled, cross-over trial. Participants consumed either a coffee cherry extract supplement containing 200 mg caffeine and 15 mg polyphenols (CB) or placebo (PLA), before exercising for 30 min on a cycle ergometer at 79 ± 1% V̇O_2max followed by a 15 min time trial (TT1). A second supplement was then consumed with 1 g·kg bm^-1 carbohydrate and a second time trial (TT2) was performed the following morning. Blood samples were collected throughout, and muscle biopsies were collected immediately after TT1 (0 h), and at 4 and 24 h.

Plasma caffeine and chlorogenic acid concentrations increased during exercise and subsequent recovery in CB compared to PLA (p < 0.001). Total work performed during TT1 was 4.6% ± 1.5% greater with CB than PLA (3.14 ± 0.15 vs. 3.02 ± 0.17 kJ·kg^-1; Hedge's g [95% confidence interval] = 0.8 [0.2, 1.4]; p < 0.05). Perceived exertion was lower during steady-state exercise with CB (p < 0.05); respiratory exchange ratio did not differ. From 0 to 4 h recovery, muscle glycogen content increased similarly in PLA and CB by 64 ± 13 and 44 ± 10 mmol·kg dw^-1, respectively, and by 53 ± 8 and 45 ± 10 mmol·kg dw^-1 from 4 to 24 h (P < 0.001).

We report that an extract from whole Coffea arabica cherry containing a low dose of caffeine and polyphenols is ergogenic but was not shown to enhance muscle glycogen resynthesis following post-exercise consumption of 1 g·kg bm^-1 carbohydrate. Clinical trials registration: Registered with clinicaltrials.gov on 10/01/2022 as NCT05404841 (URL: https://clinicaltrials.gov/study/NCT05404841).