Influence of 6-week, 6 days per week, training on pituitary function in recreational athletes.

Abstract

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 [ig thyrotropin releasing hormone (TRH), 100 [tg gonadotrophin-releasing hormone (GnRH), 100 [tg corticotrophin releasing hormone (CRH), 50 [tg 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, folliclestimulating 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.

New aspects of the hormone and cytokine response to training

“…Similar findings can be found for all hypothalamopituitary-peripheral hormonal axes with a biphasic response to overload involving predominantly peripheral mechanisms in early phases of overload and of more central mechanisms in more prolonged phases of overload and overtraining (Lehmann et al 1993b(Lehmann et al , 1997. In reality, however, there is a more gradual change from the compensated to the decompensated phase of response.…”

“…This is schematically drawn in Fig. 3 for the HPA axis (Barron et al 1985;Lehmann et al 1993b;Urhausen et al 1998;Wittert et al 1996).…”

Hormonal Responses to Endurance Training and Overtraining in Female Athletes

“…Serum cortisol at rest has been suggested to increase with heavy training (1,26) and overtraining (28), but it has also been found to decrease (21) and to be lower in elite than in good distance runners (6). In the present study there were both increases and decreases in serum cortisol at rest in each group.…”

Prevention, diagnosis and treatment of the overtraining syndrome: Joint consensus statement of the European College of Sport Science (ECSS) and the American College of Sports Medicine (ACSM)

“…in higher brain centres will certainly influence hypothalamic output (Lachuer et al 1994). Lehmann et al (1993a) introduced the concept, that hypothalamic function reflects the state of OR or the OTS because the hypothalamus integrates many of the stressors. It has been shown that acute stress not only increases hypothalamic monoamine release, but consequently corticotrophic releasing hormone (CRH) and adrenocorticotrophic hormone (ACTH) secretion (Shintani et al 1995).…”