The purpose of this study was to examine cardiorespiratory fitness variables and body composition of 5 regular middle-aged swimmers， aged
50-55.The subjec swim almost everyday for the past 8-17 years(x=12.8 yrs.)

The comparison had been made between the middle-aged swimmers and nonregular young ex-exercisers of 5 students from a local college, ared 22 in average. Also, data in this research was used to compare with the results found by foreign researchers.

Within the limits of this study,the author found that there was no significant difference in vital capacity,predicted Vo2max,heart rate responses to the same word load (75 watts),maximal heart rate,maximal total work,PWC170,and blood pressure during exercise between the middle-aged swimmers and young clooege students,except for body fat percentage(P<.01). Furthermore,some varibles showed our middleaged swimmers had better cardiorespiratory fit ness than both sedentarv and active people with the same age in other countries.

It was concluded that regular swimming participation could make middle-aged people younger than it normally would be in terms of cardiorespiratiory fitness.