The Effects of Acute Caffeine Supplementation in Combination with Postactivation Performance Enhancement on...

While both post-activation performance enhancement (PAPE) and caffeine (CAF) independently enhance performance, their combined effects on physical performance and the levels of central and peripheral fatigue remain unexplored.

This study assessed the impact of the PAPE method and CAF supplementation on central and peripheral fatigue following a fatigue-inducing protocol in elite male volleyball athletes.

The study employed a convenience sampling method to recruit 40 voluntary participants (18-30 y), who were then divided into 4 groups: PAPE group (N = 10), CAF group (N = 10), PAPE + CAF group (CAF + PAPE, N = 10), and control group (CG, N = 10). The CAF group received a CAF supplement of 6 mg/kg of body mass 20 min before the warming up for 10 min, whereas the PAPE group performed 2 sets of back squats at 80% of 1RM (4 reps/set) 2 min before the protocol.

Between-group comparisons revealed that the PAPE + CAF group demonstrated a significant improvement in the performance variables, including time to exhaustion, number of rounds, and serum dopamine concentrations, compared with all other groups (P < 0.05), whereas serum ammonia, serotonin, and prolactin concentrations decreased significantly compared with all other groups (P < 0.05). The CAF group also showed higher values in these performance and biochemical measures than the CG and PAPE groups, but these were lower than those in the CAF + PAPE group (P < 0.05). No significant differences were found for rating of perceived exertion or uric acid (P > 0.05).

This study confirms CAF's primary role in enhancing performance and reducing fatigue. The combined CAF + PAPE intervention provided a distinct advantage only for the number of rounds completed, but showed no significant benefit over CAF alone for time to exhaustion or most biochemical markers.