Growth hormone responses to repeated maximal cycle ergometer exercise at different pedaling rates
| Autor: | Mary E. Nevill, Keith Stokes, H. K. A. Lakomy, George M. Hall |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male medicine.medical_specialty Blood Volume Time Factors Physiology business.industry Human Growth Hormone musculoskeletal neural and ocular physiology education Osmolar Concentration Growth hormone Bicycling Endocrinology Sprint Physiology (medical) Internal medicine medicine Exercise Test Cycle ergometer Humans Bicycle ergometer Cycling business human activities |
| Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 92(2) |
| ISSN: | 8750-7587 |
| Popis: | The present study examined the growth hormone (GH) response to repeated bouts of maximal sprint cycling and the effect of cycling at different pedaling rates on postexercise serum GH concentrations. Ten male subjects completed two 30-s sprints, separated by 1 h of passive recovery on two occasions, against an applied resistance equal to 7.5% (fast trial) and 10% (slow trial) of their body mass, respectively. Blood samples were obtained at rest, between the two sprints, and for 1 h after the second sprint. Peak and mean pedal revolutions were greater in the fast than the slow trial, but there were no differences in peak or mean power output. Blood lactate and blood pH responses did not differ between trials or sprints. The first sprint in each trial elicited a serum GH response (fast: 40.8 ± 8.2 mU/l, slow: 20.8 ± 6.1 mU/l), and serum GH was still elevated 60 min after the first sprint. The second sprint in each trial did not elicit a serum GH response ( sprint 1 vs. sprint 2, P < 0.05). There was a trend for serum GH concentrations to be greater in the fast trial (mean GH area under the curve after sprint 1vs. after sprint 2: 1,697 ± 367 vs. 933 ± 306 min · mU−1 · l−1; P = 0.05). Repeated sprint cycling results in an attenuation of the GH response. |
| Databáze: | OpenAIRE |
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