BACKGROUND: The swimming community has shown considerable interest in using dry-land warm-ups as a method of impacting performance. This study compared the effects of high-resistance pull-over and swimming warm-up in semi-tethered resisted swimming. METHODS: An incremental-load semi-tethered swimming test was individually administered in 20 national-competitive swimmers to determine the load maximizing swimming power. In different sessions, participants tested such a load 6 min after a swimming warns-up (SWIJ) or a dry-land warm-up (DLWU: 3 pull-over reps at 85% of the one-repetition maximum). Kinetic variables (velocity, force, acceleration, impulse, power rate of force development [RFD] and intra-cycle variation), were obtained with a linear encoder through trapezoidal integration regarding time. Kinematic variables (distance, time, stroke-rate and stroke-length), were obtained by video recordings. The differences between protocols were observed by paired-samples t-test (ANOVA). Pearson's coefficient explored correlations between kinetics and kinematics variables; significance was set at P<0.05. RESULTS: DLWU increased RFD (34.52 +/- 16.55 vs. 31.29 +/- 13.70 N/s; Delta=9.35%) and stroke-rate (64.70 +/- 9.84 vs. 61.56 +/- 7.07 Hz; Delta=5.10%) compared to SWU, but decreased velocity, force, acceleration, impulse and power. During the incremental-load test velocity and power were higher than obtained after SWU (1.21 +/- 0.14 vs. 1.17 +/- 0.12 m/s; Delta=3.06%), (51.38 +/- 14.93 vs. 49.98 +/- 15.40 W; Delta=2.72%), suggesting enhancements prompted by the test itself. Correlations between stroke-length with impulse (r=0.76) and power (r=0.75) associated kinetics with kinematics. CONCLUSIONS: Potentiation responses were present after the dry-land warm-up. However, swimmers may benefit more from submaximal prolonged conditioning activities such as resisted swimming rather than high-resistance dry-land sets to obtain performance enhancements.
