Kaoru Umebayasi

Tennis used to be estimated that the exercise intencity was within the AT (Anaerobic Threshold) level formerly according to the preceding studies. There were, however, some reports which indicated that the playing load of modern tennis often overpassed the onset of blood lactate accumulation(OBLA). One of the possible explanations for exceeding the AT level in modern tennis is that the tempo of modern tennis may be rapider than before. Therfore, the present study was desighned to measure and compare the time between one ground stroke and next one in the tennis games respectively at 80's and the present, 1998-1999. The following results, statistically significant at 5% level, were obtained. 1)The rally (ground stroke) tempo at the present, 1998-1999 was rapider than 80's. without distinction of sex, 0.30(sec) in female, 0.14(sec) in male. 2)The rally (ground stroke) tempo of the net player was rapider than baseliner without distinction of sex, 0.20〜0.30(sec) in female at 80's, 0.18〜0.24(sec) in male at 80's, 0.06(sec) in male at 1999. 3)The rally (ground stroke) tempo in female at 80's was approximately 1.61 (sec) and it was 0.16(sec) slower than the tempo in male. The rally (ground stroke) tempo in female at the present, 1999 was equal to the tempo in male. The general conclusions drawn from these data is that the rally (ground stroke) tempo accelerating in modern tennis reinforces the intencity of exercise in tennis.