The prolactin response of males to a standard MVO2 treadmill test

The concentration of serum prolactin in response to a standard MVO2 treadmill stress test to self-perceived exhaustion was investigated in 19 normal healthy males. The prolactin concentration remained stable for an interval of approximately 20 minutes from the beginning of exercise. Peak prolactin levels, observed after the subjects had stopped exercising, indicated a mean 2.6-fold increase over pre-exercise levels. The concentration of prolactin did not increase before an exercise intensity reflecting a VO2 of 40 ml/kg/min had been reached. There was no relationship between the MVO2 of the 19 male subjects and their prolactin increment in response to exercise.