Effects of different heavy-resistance exercise protocols on plasma beta-endorphin concentrations
| Autor: | Everett A. Harman, Steven J. Fleck, Peter N. Frykman, Joseph E. Dziados, Louis J. Marchitelli, Scott E. Gordon, William J. Kraemer, N. T. Triplett, Robert P. Mello |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Adult
Male medicine.medical_specialty Hydrocortisone Weight Lifting Physiology Physical Exertion Physical exercise chemistry.chemical_compound Blood serum Ammonia Heart Rate Physiology (medical) Internal medicine Blood plasma medicine Humans Urea Anaerobiosis Exercise physiology Creatine Kinase Whole blood Creatinine biology Chemistry beta-Endorphin Endocrinology Lactates biology.protein Creatine kinase medicine.drug |
| Zdroj: | Journal of Applied Physiology. 74:450-459 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1993.74.1.450 |
| Popis: | To examine the changes of plasma beta-endorphin (beta-EP) concentrations in response to various heavy-resistance exercise protocols, eight healthy male subjects randomly performed each of six heavy-resistance exercise protocols, which consisted of identically ordered exercises carefully designed to control for the repetition maximum (RM) resistance (5 vs. 10 RM), rest period length (1 vs. 3 min), and total work (joules). Plasma beta-EP, ammonia, whole blood lactate and serum cortisol, creatine kinase, urea, and creatinine were determined preexercise, midexercise, immediately postexercise, and at various time points after the exercise session (5 min-48 h), depending on the specific blood variable examined. Only the high total work-exercise protocol [1 min rest, 10 RM load (H10/1)] demonstrated significant increases in plasma beta-EP and serum cortisol at midexercise and 0, 5, and 15 min postexercise. Increases in lactate were observed after all protocols, but the largest increases were observed after the H10/1 protocol. Within the H10/1 protocol, lactate concentrations were correlated (r = 0.82, P < 0.05) with plasma beta-EP concentrations. Cortisol increases were significantly correlated (r = 0.84) with 24-h peak creatine kinase values. The primary finding of this investigation was that beta-EP responds differently to various heavy-resistance exercise protocols. In heavy-resistance exercise, it appears that the duration of the force production and the length of the rest periods between sets are key exercise variables that influence increases in plasma beta-EP and serum cortisol concentrations. Furthermore the H10/1 protocol's significant challenge to the acid-base status of the blood, due to marked increases in whole blood lactate, may be associated with mechanisms modulating peripheral blood concentrations of beta-EP and cortisol. |
| Databáze: | OpenAIRE |
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