Physiological and metabolic responses to work in heat with graded hypohydration in tropical subjects
| Autor: | G. Pichan, K. Sridharan, R. K. Gauttam |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Adult
medicine.medical_specialty Hot Temperature Time Factors Physiology Physical Exertion Poison control Physical exercise Work rate SWEAT Electrolytes Animal science Oxygen Consumption Body Water Physiology (medical) Heart rate medicine Humans Orthopedics and Sports Medicine Sweat Tropical Climate business.industry Respiration Osmolar Concentration Public Health Environmental and Occupational Health General Medicine Thermoregulation Surgery Moderate exercise Breathing Exercise Test business |
| Zdroj: | European journal of applied physiology and occupational physiology. 58(1-2) |
| ISSN: | 0301-5548 |
| Popis: | Studies were conducted on 25 healthy male volunteers aged 20-25 years drawn randomly from the tropical regions of India. The subjects initially underwent an 8 day heat acclimatization schedule with 2 hours moderate work in a climatic chamber at 45 degrees C DB and 30% RH. These heat acclimatized subjects were then hypohydrated to varying levels of body weight deficits, i.e. 1.3 +/- 0.03, 2.3 +/- 0.04 and 3.3 +/- 0.04%, by a combination of water restriction and moderate exercise inside the hot chamber. After 2 hours rest in a thermoneutral room (25 +/- 1 degree C) the hypohydrated subjects were tested on a bicycle ergometer at a fixed submaximal work rate (40 W, 40 min) in a hot dry condition (45 degrees C DB, 30% RH, 34 degrees C WBGT). Significant increases in exercise heart rate and oral temperature were observed in hypohydrated subjects as compared to euhydration. Sweat rate increased with 1% and 2% hypohydration as compared to euhydration, but a significant decrease was observed with 3% hypohydration. Na+K+ concentrations in arm sweat increased with increase in the level of hypohydration. Oxygen consumption increased significantly only when hypohydration was about 2% or more. It appears that the increased physiological strain observed in tropical subjects working in heat with graded hypohydration is not solely due to reduced sweat rates. |
| Databáze: | OpenAIRE |
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