The Mediating Effects of Caffeine Ingestion and Post-Activation Performance Enhancement on Reactive Dive Times in Goalkeepers

Background. The reactive abilities of goalkeepers are crucial and may directly impact match results. Therefore, research on factors that may enhance goalkeeper performances during diving tasks (DT) and how these factors are mediated would provide valuable information for coaches and goalkeepers. Objectives. The purpose of this investigation was to: (i) assess the impact of caffeine consumption and post-activation performance enhancement (PAPE) on the DT ability of goalkeepers and (ii) investigate the potential mechanisms responsible for changes in DT performance. Methods. Purposive sampling was utilized, coupled with a double-blinded cross-over study design. 25 soccer goalkeepers volunteered for the study (age: 22.50 ± 4.32 years; height: 1.67 ± 0.78 m; mass: 66.58 ± 11.30 kg). Players were evaluated for simple reaction time (SRT), dynamic reaction time (RT), jump height (JH), and reactive DT under three treatment conditions: control, caffeine, and PAPE. Results. Improvements in DT are mediated by improvements in RT rather than changes in JH (i.e. explosiveness) when consuming caffeine (β = -0.09, t (48) = -3.17, P =0.002) or performing plyometric drills (β = -0.14, t (48) = -4.47, P <0.001). Both treatments were similarly effective (Mdiff = 0.00 sec, P < 0.994). Conclusion. Caffeine consumption or PAPE is similarly effective in improving goalkeeper DT performances. These improvements may likely be related to changes in dynamic RT, thereby implying that faster information processing by the CNS is the likely source for improvements.