The effect of warm-up on responses to intense exercise.

The purpose of this study was to determine if prior physical activity (warm-up) affected physiological responses to intense exercise. Eight highly trained collegiate swimmers performed a paced 365.8-m (440 yds) intense swim (mean +/- SE, 94.4 +/- 3.3% VO2max) 5 min after the following warm-up conditions: trial N, no warm-up; trial S, an intensity-specific interval set (4 x 45.7 m with one-min rest intervals at the intense swim pace); trial M, a mild-intensity, long-duration swim (1371.6 m at 64.7 +/- 3.3% VO2max); and trial MS, a mild-intensity, long-duration swim (1188.7 m at the same pace as trial M) followed by the intensity-specific interval set (trial S). When comparing trial N with trials M and MS, stroke distance (m/stroke) was significantly (p less than 0.05) lower during the last 91.4 m of the intense, paced swim and 3-, 5-, 8- and 10-min recovery blood lactate levels and one-minute recovery heart rates were significantly elevated (p less than 0.05). There was no significant difference (p greater than 0.05) in stroke distance during the final 91.4 m of the intense swim between trials S and N. There were no significant differences for any variables between trials M and MS. These results suggest that a warm-up consisting of mild-intensity, long-duration exercise was beneficial compared to no warm-up and that intensity-specific exercise was not a vital component of warm-up. Although performance was not directly measured, these data demonstrate the benefit of warm-up.