Influence of 6-week, 6 days per week, training on pituitary function in recreational athletes.
The influence on pituitary function of 6 weeks of training on 6 days a week was examined in six recreational athletes. Endurance training on a bicycle ergometer for 31-33 min was performed on 4 days each week at 90-96% (weeks 1-3) and 89-92% (weeks 4-6) of the 4 mmol lactate thresholds determined on day 0 and day 21, respectively, with interval training of 3-5 x 3-5 min in addition on 2 days a week at 117-127% and 115-110%, respectively. Determination of the serum hormone levels and a combined pituitary function test (200 micrograms thyrotropin releasing hormone (TRH), 100 micrograms gonadotrophin-releasing hormone (GnRH), 100 micrograms corticotrophin releasing hormone (CRH), 50 micrograms growth hormone releasing hormone (GHRH)) were made before training, after 6 weeks of training and after another 3 weeks of recovery. Training increased performance at 2 mmol lactate by 25%, at 4 mmol by 12%, and maximum performance by approximately 12%. The releasing hormone-stimulable prolactin, thyroid stimulating hormone (TSH) and somatotrophic hormone (STH) synthesis-secretion capacity remained unchanged, the adrenocorticotrophic hormone (ACTH) was increased after training. Cortisol release was reduced, follicle-stimulating hormone (FSH)-synthesis-secretion capacity was increased after training, and the luteinizing hormone (LH)-synthesis-secretion capacity reduced. This had no influence on base or exercise-induced serum hormone levels (cortisol, aldosterone, insulin, prolactin, FSH, LH, TSH, ACTH, ADH and STH), which showed no dependence on training, except for free testosterone which showed a decreasing trend (P < 0.10) of 19-25% and post-exercise ACTH which showed an increasing trend of 33% (P < 0.10). Conditioning (cortisol sensitivity and ACTH response) or adaptation (FSH and LH responses) to changed testosterone serum levels and altered spermatogenesis is discussed.
Lehmann
M
M
Department of Sports and Performance Medicine, University Clinic Freiberg, Germany.
Knizia
K
K
Gastmann
U
U
Petersen
K G
KG
Khalaf
A N
AN
Bauer
S
S
Kerp
L
L
Keul
J
J
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D006065:Gonadotropins, Pituitary / Q000097:blood; D006801:Humans; D010806:Physical Education and Training; D010809:Physical Fitness / Q000502:physiology*; D010901:Pituitary Function Tests; D010902:Pituitary Gland / Q000378:metabolism*; D013177:Sports / Q000502:physiology*
D006065:Gonadotropins, Pituitary; D000324:Adrenocorticotropic Hormone