PLASMA GROWTH HORMONE AND PROLACTIN LEVELS IN HEALTHY SEDENTARYYOUNG MEN AFTER SHORT-TERM ENDURANCE TRAINING IN HOT ENVIRONMENT

Pituitary hormones have an important role during exercise. The aim of the study to investigate the effect of endurance training in hyperthermic environment on plasma growth hormone (GH) and prolactin (PRL) levels in non-trained healthy subjects. Twenty-four untrained healthy men participated in an 8-week progressive two different endurance-training program. Subjects were divided into two groups: an interval running group (IR), and continuously running group (CR). Both groups were performed 3 days/week. GH, PRL and VO2max were assessed at pre- and post-training period. In addition, body temperature (BT) was analyzed at the beginning and immediately after each training. While exercise type was effective on plasma PRL (8.52 ve 6.50 ng/ml IT and CT, P < 0.02) it did not cause any significant change on plasma GH; yet there was an increase in interval training group (0.418 and 1.476 ng/ml). Yet, in plasma PRL, there was an increase in continues training group (5.75 and 7.24 ng/ml). Although body temperature was generally high in intervally training person (36.05 and 36.47 °C), it eventually increased in continuous condition after the programme compared with previous rates (35.85 and 36.47 °C). Both types of training increased body temperature significantly (P<0.0001). Hereby we can say that, eight weeks of regular exercise results in a significant increase in the plasma PRL levels due to the increased body temperature, but the increase of GH levels was not significantly.