The present study was designed to examine influences of rest intervals between warm-up and subsequent criterion exercise on the duration of effects of the mild-and the high-intensity warm-up. 7 male collegiate competitive swimmers were tested for blood lactate concentration (La), heart rate (HR), and ratings of perceived exertion (RPE) during and after an intense, paced (95% maximal velocity of each swimmer's best records) 200m front crawl (CS) following three formal warm-up and an informal warm-up (stretching only, NW) conditions. Total meters of formal warm-up which consisted of various intermittent sets including kicking, pulling, and swimming was identical (1800m) among three trials. The formal warm-up protocols were 1) a mild-intensity warm-up including 10×50 m front crawl raised La by 2-3 mM followed by 20 min rest (WM20), 2) a mild-intensity warm-up corresponding to WM20 followed by60 min rest (WM60) and 3) a high-intensity warm-up including 10×50 m front crawl raised La by 6-8 mM followed by 60 min rest (WH60).
　The mild-intensity warm-up resulted in significantly (p<0.05) lower La after CS (7.73±0.85mM for WM20 and 7.93±0.79mM for WM60) as compared to NW trials (9.53±0.97mM), although no significant trial differences apparent for HR at any stage of CS and RPE after CS. These results indicate that the mild-intensity warm-up may contribute to relieve the acidosis during the races of 100−200 m, if a rest intervals of 20-60 min is introduced between warm-up and the race. On the other hand, there was no significant differences for La after CS between NW and WH60 (8.73±1.00mM). In WH60, continuous decreases of the rectal tem-perature (Tr) during rest intervals between warm-up and CS was found, although there was no significantly decrease of Tr from 30 min after the end of warm-up onward in WM60. Furthermore, a decrease in Tr during rest intervals was significantly (p<0.01) different between WH60 (-0.87±0.13°C) and WM60 (-0.53±0.11°C). Therefore, it appeared that a striking decrease in Tr during a, rest intervals effaced some beneficial effects of warm-up.

DESCENTE SPORTS SCIENCE Vol.18/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE