[Analysis of factors affecting anaerobic threshold in healthy subjects]

The anaerobic threshold (AT) is used to determine the exercise capacity in patients with heart failure and healthy subjects. To determine the factors affecting AT, we determined the AT in healthy subjects, and examined the factors that determine AT in healthy subjects. One hundred and sixteen healthy subjects (79 men and 37 women) performed on a bicycle a stepwise increasing submaximal exercise. During the work test the parameters usually used in the detection of AT (Vo2, Vco2, VE), blood pressure, heart rate and oxygen saturation were recorded by a computerized system every minute. AT was determined from changes in ventilation and gas-exchange. The fat index was calculated from height and body weight measured at the beginning of the ventilatory function test. A significant correlation was obtained between AT and age, AT and fat index, AT and %VC, AT and maximum heart rate during exercise, AT and recovery rate of heart rate after exercise, and AT and Vo2 at rest. In addition, we examined the relationship among the parameters in 4 groups according to sex and age (30-49; younger, 50-69; older), because sex and age affected most parameters. We found a significant correlation between AT and fat index (older men and women), AT and %VC (younger and older women), AT and Vo2 at rest (younger and older men). We considered that the main factors that determined AT in healthy subjects were age, sex, fat index, %VC and Vo2 at rest.