Effects of two warm-up protocols on isokinetic knee strength, jumping ability and sprint swimming performance in competitive swimmers

The purpose of this study was to examine the effects of different dryland warm-up protocols on knee isokinetic strength, vertical jumping, and sprint performance in competitive swimmers. Twenty-four male swimmers were randomly assigned to the FIFA 11 + group (n = 12) or the post-activation performance enhancement (PAPE) group (n = 12). The FIFA 11 + group performed the FIFA 11 + warm-up program three times per week for 6 weeks, whereas the PAPE group consisted of performing general activities and three sets of five drop jumps. Performance test included concentric (con) and eccentric (ecc) isokinetic strength of the quadriceps (Q) and hamstrings (H) of the dominant (DL) and non-dominant (NDL) limbs at three angular velocities, countermovement jump (CMJ), squat jump (SJ) and a 50-m time trial. The conventional (Hcon: Qcon) and functional (Hecc: Qcon) ratios were calculated pre- and post- intervention. The FIFA 11 + group showed a significant increase in DL-Hcon (p < 0.05, ES = 1.0-1.8), and NDL-Hcon (p < 0.05, ES = 1.0-1.6) in all angular velocities, and DL-Qcon (p < 0.05, ES = 0.9) at 60°·s^{- 1}. The PAPE group significantly improved DL-Qcon at 180°·s^{- 1}, 240°·s^{- 1} (both p < 0.05, ES = 1.0), and NDL-Qcon at 240°·s^{- 1} (p < 0.05, ES = 0.9). Additionally, FIFA 11 + showed significant improvement in DL-Hcon and NDL-Hcon (both p < 0.05, ES = 0.9-1.8) compared with PAPE. FIFA 11 + increased DL-Hcon: Qcon₆₀ (p < 0.05, ES = 1.1) and NDL- Hcom: Qcon_60,240 (both p < 0.05, ES = 1.2) compared with PAPE. Both groups significantly improved CMJ (FIFA 11 + p < 0.01, ES = 0.4 and PAPE p < 0.01, ES = 0.3), SJ (both p < 0.01, ES = 0.6) and 50-m swimming performance (FIFA 11 + p < 0.05, ES = -0.8 and PAPE p < 0.05, ES = -0.6).Both warm-up protocols showed similar improvements in jumping ability and sprint swimming performance. The FIFA 11 + seemed more efficient in improving lower limb isokinetic strength and conventional strength ratios in male competitive swimmers.