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THE HORMONAL RESPONSE TO PHYSICAL EXERCISE
Author(s) -
SUTTON J. R.,
YOUNG J. D.,
LAZARUS L.,
HICKIE J. B.,
MAKSVYTIS J.
Publication year - 1969
Publication title -
australasian annals of medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.596
H-Index - 70
eISSN - 1445-5994
pISSN - 0571-9283
DOI - 10.1111/imj.1969.18.2.84
Subject(s) - medicine , endocrinology , basal (medicine) , hormone , glucagon , anaerobic exercise , physical exercise , insulin , physiology
SUMMARY Studies of the hormonal response to physical exercise were performed on young males who were classified as physically fit or unfit. The studies included serial measurements of blood sugar, plasma free fatty acids (FFA), serum growth hormone (HGH), serum insulin, serum glucagon and plasma cortisol levels during and following a 30‐minute period of maximal physical exercise. The hormonal response in both groups was similar except in the case of HGH. In both groups there was an elevation of HGH level during exercise, but in the fit group HGH returned to basal levels within 30 minutes, whereas in the unfit group the HGH level continued to rise for a further hour before decreasing. These results confirm that HGH secretion occurs during vigorous muscular exercise, and that in the unfit subject there is a delay in the return of HGH to basal levels following exercise. Studies during submaximal exercise revealed an elevation of HGH only in the unfit group. The possibility of anaerobic metabolites acting as the stimulus for HGH in exercise was investigated by infusion of sodium lactate, which caused a significant elevation of HGH level. From the above data we conclude that a characteristic of physical fitness is a rapid return of HGH secretion to basal levels following vigorous muscular exercise.