Effect of acute caffeine supplementation before intermittent high-intensity exercise on cytokine levels and psychobiological parameters: A randomized, cross-over, placebo-controlled trial
Marcus V.L.Dos Santos Quaresma Cytokine Volume 144, August 2021, 155583
The present study aimed to verify the effects of caffeine supplementation on psychobiological parameters and its relationship with inflammatory cytokines in non-athlete subjects. We hypothesized that IL-10 may be responsible for the reduction in fatigue perception in response to caffeine supplementation. It was a randomized, double-blinded, cross-over, placebo-controlled study. Ten non-athlete subjects (26.9 ± 4.01 years old; 73.44 ± 9.57 kg; 15.94 ± 4.32 body fat kg) were evaluated.
Sixty-min after caffeine (6 mg−1.kg−1 body mass) or placebo supplementation, high-intensity interval exercise test (1 min at 90% of Wmax and 2 min at 50% of Wmax) was performed to maximum voluntary exhaustion. Cytokine concentrations and psychobiological parameters were evaluated before (BE), immediately after (post-PE) and 1 h after exercise (1 h post-PE). We verify that IL-6 (0.35; 95% CI: 0.13 to 0.56; z = 3.24; p = 0.001; d = 1.14) and IL-10 (9.06; 95% CI 0.41 to 17.70; z = 2.05; p = 0.04; d = 1.12) increases post-PE in CAF group versus PLA group. Still, IL-10 levels were higher in CAF group 1 h post-PE (25.04; 95% CI: 8.95 to 41.31; z = 3.05; p = 0.002; d = 1.9) than PLA group. Moreover, 1 h post-PE vigor level was higher in the CAF group versus PLA group (4.53; 95% CI: 1.27 to 7.80; z = 2.72; p = 0.006; d = 0.46), and fatigue was lower in CAF group than PLA group (-5.08; 95% CI: −9.93 to −0.227; z = -2.05; p = 0.040; d = 0.67).
We conclude that 1 h post-PE caffeine was able to decrease fatigue and increase vigor perception. IL-10 levels were higher 1 h post-PE in CAF group, suggesting, according to our hypothesis, that IL-10 may be associated with decrease fatigue perceptions after exercise.