流水プールを用いた水泳疲労性閾値としての Critical Swimming Velocity の簡便的決定法の検討

The purpose of this study was to investigate a simple method for determination of critical swimming velocity (Vcri). Vcri is defined by Wakayoshi et al. (1992) as the swimming speed which could theoretically be maintained forever without exhaustion, and is expressed as the slope of a regression line between swimming distance (D) and swimming time (T) obtained at various swimming speeds. To determine Vcri, 20 well-trained swimmers were measured at several swimming speeds ranging from 1.25 m/sec to 1.8 m/sec until exhaustion in a swimming flume. A regression analysis of D on T calculated for each swimmer showed highly linear relationships (r=0.999, p) was measured in a normal pool. Significant correlations were obtained between Vcri and V_. This result showed that Vcri corresponded to maximal lactate steady state. Investigation of the relationship between Vcri and estimated maximal effort swimming velocity (30, 60, 120, 180, 240 and 300 seconds), calculated from the regression equations of Vcri, revealed a significant relationship in swimming periods which were longer than 120 seconds. This result was similar to the maximal swimming periods exceeding about 65～75% of the aerobic contribution of total energy yield found by Ogita et al. These data suggest that Vcri could be calculated by performing one maximal effort swimming test for approximately 2～3 minutes