Thirty-two male students who participated in the Tsukuba marathon race were measured for body mass(BM), grip strength(GS), maximal force and rate of force development(RFD)in isometric knee extension(ISO), jumping height(JH)for the counter-movement-jump(CMJ), and JH and contact time(CT)for the 5-rebound-jump(5RJ)before and after the race.Also, maximal oxygen uptake(VO_2max)and maximal steady state corresponding to an intensity giving a blood lactate level of 2.2mmol/l of blood lactate(MMS)of 22 of the subjects were measured on a separate day to the race.The results were as follows:1)Average race time was 3 h 55 min 27 s.Average running speed in the second half of the race was significantly lower than in the first half.2)BM, GS, maximal force and RFD in ISO, JH of CMJ, and JH of 5RJ and 5RJindex(=JH/CT)were significantly lower after the race.CT of 5RJ after the race also increased significantly.Furthermore, relative changes in the maximal force and RFD in ISO, CT of 5RJ and 5RJindex after the race were significantly greater than the relative changes in BM, GS and JH of CMJ after the race.3)Average running speed during the race was correlated significantly with VO_2 max and MSS.However, significant relationships were not observed between average running speed during the race and leg muscular strength or power measured before the race.4)The relative change in running speed from the first to the second half of the race was correlated significantly with the relative change in JH of 5RJ after the race.These results suggest that muscular strength and stretch-shorting cycle movement ability of leg muscles were damaged during the marathon race.Therefore, reducing this damage during the race may help to maintain running speed in the second half of the race.