Abstract
To establish whether or not hypoxia influences the training-induced adaptation of hormonal responses to exercise, 21 healthy, untrained subjects [26 (2) years, mean (SE)] were studied in three groups before and after 5 weeks' training (cycle ergometer, 45 min· day-1, 5 days· week-1). Group 1 trained at sea level at 70% maximal oxygen uptake ( {Mathematical expression}O2max), group 2 in a hypobaric chamber at a simulated altitude of 2500 m at 70% of altitude {Mathematical expression}O2max, and group 3 at a simulated altitude of 2500 m at the same absolute work rate as group 1. Arterial blood was sampled before, during and at the end of exhaustive cycling at sea level (85% of pretraining of {Mathematical expression}O2max). {Mathematical expression}O2 increased by 12 (2)% with no significant difference between groups, whereas endurance improved most in group 1 (P < 0.05). Training-induced changes in response to exercise of noradrenaline, adrenaline, growth hormone, β-endorphin, glucagon, and insulin were similar in the three groups. Concentrations of erythropoietin and 2,3-diphosphoglycerate at rest did not change over the training period. In conclusion, within 5 weeks of training, no further adaptation of hormonal exercise responses takes place if intensity is increased above 70% {Mathematical expression}O2max. Furthermore, hypoxia per se does not add to the training-induced hormonal responses to exercise.
Original language | English (US) |
---|---|
Pages (from-to) | 303-309 |
Number of pages | 7 |
Journal | European Journal of Applied Physiology and Occupational Physiology |
Volume | 68 |
Issue number | 4 |
DOIs | |
State | Published - Jul 1 1994 |
Keywords
- ACTH
- Catecholamines
- Erythropoietin
- Growth hormone
- Insulin
ASJC Scopus subject areas
- Physiology
- Public Health, Environmental and Occupational Health