The effect of warm-up on intermittent sprint performance and selected thermoregulatory parameters

Objectives: To investigate the effect of various warm-up intensities based upon individual lactate thresholds on subsequent intermittent sprint performance, as well as to determine which temperature (muscle; T-mu, rectal; T-re or body; T-b) best correlated with performance (total work, work and power output of the first sprint, and % work decrement). Design: Nine male team-sport participants performed five 10-min warm-up protocols consisting of different exercise intensities on five separate occasions, separated by a week. Methods: Each warm-up protocol was followed by a 6 x 4-s intermittent sprint test performed on a cycle ergometer with 21-s of recovery between sprints. T-mu, T-re, and T-b were monitored throughout the test. Results: There were no differences between warm-up conditions for total work (J kg(-1); P = 0.442), first sprint work (J kg(-1); P = 0.769), power output of the first sprint (W kg(-1); P = 0.189), or % work decrement (P = 0.136), respectively. Moderate to large effect sizes (>0.5; Cohen's d) suggested a tendency for improvement in every performance variable assessed following a warm-up performed at an intensity midway between lactate inflection and lactate threshold. While T-mu, T-re, T-b, heart rate, ratings of perceived exertion and plasma lactate increased significantly during the exercise protocols (P < 0.05), there were no significant correlations between T-mu, T-re, and T-b assessed immediately after each warm-up condition and any performance variable assessed. Conclusions: Warm-up performed at an intensity midway between lactate inflection and lactate threshold resulted in optimal intermittent sprint performance. Significant increases in T-mu, T-re and T-b during the sprint test did not affect exercise performance between warm-up conditions. (c) 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.