Validity of the 500 Yard Swim and 5 Kilometer Stationary Cycle Ride as Indicators of Aerobic Fitness.

Two studies were performed, under contract, to determine the validity of including a 500-yard, swim or a 5-kilometer stationary cycle ride as an aerobic fitness measure in the Navys Physical Readiness Test PRT. Participants in the swim test study were 60 college students 29 men and 31 women. Th aerobic fitness of each subject was determined from 1.5-mile run time and maximal oxygen uptake VO2max. Swimming skill, percent body fat, and 500-yard swim time were also measured. Results showed swim time to be weakly correlated with both run time and VO20max r .44 and -.32 respectively. Swimming skill was the primary determinant of swim time r -.83. In the second study, 20 college students 9 men and 11 women performed a series of 5-kilometer rides on a stationary cycle ergometer for time. Maximum oxygen uptake and 1.5-mile run time were also measured. Cycle ride time was significantly correlated with both run time and VO20max r .94 and -.72 respectively. These results indicate that factors other than aerobic fitness i.e., swimming skill significantly affect 500-yard swim performance, and therefore, its validity as a measure of aerobic fitness has to be seriously questioned.