Cardiovascular responses to exercise in middle-aged men after 10 days of bedrest
| Autor: | Robert F. DeBusk, Victor A. Convertino, D Goldwater, Joseph Hung |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Male
Supine position media_common.quotation_subject Physical Exertion Blood Pressure Heart Rate Physiology (medical) Heart rate Medicine Humans Myocardial infarction media_common business.industry Convalescence VO2 max Cardiorespiratory fitness Carbon Dioxide Middle Aged medicine.disease Oxygen Blood pressure Anesthesia Ventilation volume Cardiology and Cardiovascular Medicine business Bed Rest |
| Zdroj: | Circulation. 65(1) |
| ISSN: | 0009-7322 |
| Popis: | The cardiorespiratory response to 10 days of continuous recumbency was assessed in 12 healthy men, age 50 +/- 4 years, who underwent supine and upright graded maximal exercise testing before and after bedrest. The decrease in peak oxygen uptake after bedrest was greater during upright exercise (15.1%, p less than 0.05) than during supine exercise (6.1%, NS): from 25.8 +/- 5.2 to 21.9 +/- 4.5 ml/kg/min and from 24.6 +/- 5.2 to 23.1 +/- 4.8 ml/kg/min. The decrease in submaximal work was also greater in the upright than in the supine position ( p less than 0.05). Ventilation volume was significantly elevated (p less than 0.05) after bedrest during maximal and submaximal effort in both the supine and upright positions. After bedrest, peak heart rate increased 5.7% and 5.9% during supine and upright testing, respectively (p less than 0.05). The increases in rate-pressure product after bedrest were significantly larger (p less than 0.05) during upright than during supine exercise. These results indicate that orthostatic stress is the most important factor limiting exercise tolerance after bedrest in normal middle-aged men. This mechanism also increases the myocardial oxygen demands during submaximal effort after bedrest. Intermittent exposure to gravitational stress during the bedrest stage of hospital convalescence may obviate much of the deterioration in cardiovascular performance that follows myocardial infarction. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|