ABSTRACT

　The present study examined the effects of different half-time strategies on repeatedsprint ability （RSA）． In a randomized cross-over design, ten male soccer players completed two RSA tests （6, 6-s sprints separated by 24 s of passive rest, first and second halves） separated by a 15-min half-time. During the half-time, the participants were assigned to a 15-min seated rest （CON）， a 7.5-min passive heating （wearing a jacket at 5 to 12.5 min during the 15-min half-time, PAS）， a 1.5-min active heating before the end of the half-time （performing a re-warm up at 12.5 to 14 min during the 15-min half-time, ACT）， or a combination of both passive and active heating（COMB）． All trials were performed on a non-motorized treadmill in a thermoneutral environment （17.1 ± 1.1℃， 52.2 ± 8.1% relative humidity）． In CON, mean and maximum running speeds were significantly lower during the second half than during the first half （p<0.05）， but this difference was not observed in the other trials. In the half-time, PAS, ACT, and COMB did not decrease magnitudes of the drop in gastrointestinal temperature. Skin temperature at the start of the second half was significantly higher in COMB than in CON（p<0.05）． In the second half, there were no significant differences in gastrointestinal temperature, electromyography, or muscle oxygenation between trials. Herat rate during the second half was significantly higher in ACT and COMB than in CON and PAS（p<0.05）． In conclusion, PAS, ACT, and COMB improved RSA during the second half compared to CON.

DECENTE SPORTS SCIENCE Vol.45/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE