Gas exchange and neurohumoral response to exercise: influence of the exercise protocol
| Autor: | John Kjekshus, Svein Simonsen, Jonathan Myers, Lars Gullestad, Christian Hall, O Djøseland, Karin Lund, Reidar Bjørnerheim, Knut J. Berg |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Adult
Male medicine.medical_specialty Physical Therapy Sports Therapy and Rehabilitation Physical exercise Work rate Catecholamines Oxygen Consumption Internal medicine Heart rate medicine Humans Orthopedics and Sports Medicine Lactic Acid Exercise business.industry Endothelins Hemodynamics VO2 max Venous blood Endocrinology Blood pressure Epinephrine Growth Hormone Breathing Female business Atrial Natriuretic Factor medicine.drug |
| Zdroj: | Medicine & Science in Sports & Exercise. 29:496-502 |
| ISSN: | 0195-9131 |
| DOI: | 10.1097/00005768-199704000-00011 |
| Popis: | Maximal oxygen uptake varies with the exercise protocol, but the extent to which hormonal and metabolic responses to exercise are influenced by the exercise protocol has not been precisely defined. Twelve healthy subjects underwent maximal exercise testing using two incremental bicycle tests with individualized, identical work rate increments between 40 and 70 W. One protocol employed a 1-min and the other a 3-min duration per stage. Expiratory gas and venous blood were sampled at regular intervals for metabolic and hormonal analysis. Exercise duration for the 1-min and 3-min protocols was 6.0 +/- 0.1 and 14.3 +/- 0.3 min, respectively (P < 0.001). Significantly higher values were observed for peak VO2 and maximal ventilation during the 3-min protocol compared with the 1-min protocol (41.1 +/- 1.8 vs 38.3 +/- 1.6 ml.kg-1.min-1, P < 0.001; and 104.9 +/- 8.0 vs 97.2 + 5.7 l.min-1, P < 0.05, for peak VO2 and peak ventilation, respectively). However, the maximal workload achieved was higher during the 1-min versus the 3-min protocol (330 + 24 vs 280 + 21 W, P < 0.01). No differences were observed for maximal heart rate or blood pressure, whereas maximal plasma lactate was roughly twice as high during the 3-min compared with the 1-min protocol (7.5 +/- 0.8 vs 3.8 +/- 0.5 mmol.l-1, P < 0.001). Norepinephrine, epinephrine, dopamine, and growth hormone levels were generally higher throughout exercise during the 3-min compared with the 1-min protocol. When expressed as a percentage of peak VO2, however, differences in catecholamine levels were not observed. Endothelin levels did not change. We conclude that the exercise protocol profoundly influences exercise capacity as well as the metabolic and hormonal response to exercise and should be considered when using these variables to evaluate an intervention. |
| Databáze: | OpenAIRE |
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