Responses of serum hormones and factors measured with the SAN-test (feelings of well-being, activation, mood) to a submaximal work load in 83 health athletes were expressed in per cent of the values expected individually according to the respective circadian rhythm [5,6,7]. In the most subjects a significant increase of serum HGH and a significant decrease of serum T (= testosterone) was found under the work load. Within 45 min after the completion of the work the level of HGH returned to the expected one, according to the circadian rhythm, while the level of T did not. Some other minor hormonal responses were observed. No significant differences were shown between the actual values of factors measured with the SAN-test and the respective values expected according to the circadian rhythm.