Metabolic changes in man under hypokinesia and physical exercise.
It was theorized that physical exercise may be used to prevent the development of metabolic changes in man under hypokinesia (diminished muscular activity). In this investigation we assessed the efficacy of physical exercise in attenuating metabolic disturbances in twelve physically healthy men aged 19 to 23 years under 100 days of hypokinesia and 15 days of a readaptation period. The subjects were divided into an experimental and a control group with six men each. The experimental group was subjected to combined hypokinesia and physical exercise and the control group to pure hypokinesia (that is, without the use of any preventive measures). The actual experimental period was preceded by a period to establish baseline values. Both groups of men were on a diet that consisted of about 2700 kcal/day. For the simulation of the hypokinetic effect the men were kept under a liberal bed rest regimen. During the background period, hypokinetic period, and readaption period, several biochemical parameters were measured. Energy requirements were found to be suppressed, protein metabolism impaired, loss of nitrogenous products increased, fluid and electrolyte excretion accelerated, vitamin elimination was enhanced, corticosteroid blood concentration decreased, and hemoglobin and cell counts increased. It was concluded that hypokinesia caused marked debilitating metabolic changes in man. Physical exercise failed to counteract effectively the development of adverse reactions in the examined parameters under hypokinesia.
Zorbas
Y G
YG
Hypokinetic Physiology Laboratory, European Institute of Environmental Cybernetics, Athens, Greece.
Merkov
A B
AB
Nobahar
A N
AN
D000222:Adaptation, Physiological; D000305:Adrenal Cortex Hormones / Q000097:blood; D000328:Adult; D000339:Affect; D001510:Bed Rest; D001798:Blood Proteins / Q000378:metabolism; D001834:Body Water / Q000378:metabolism; D004231:Diuresis; D004573:Electrolytes / Q000652:urine; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D009132:Muscles / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism / Q000652:urine; D011506:Proteins / Q000378:metabolism; D014815:Vitamins / Q000652:urine; D014882:Water-Electrolyte Balance; D015431:Weight Loss
D000305:Adrenal Cortex Hormones; D001798:Blood Proteins; D004573:Electrolytes; D006454:Hemoglobins; D011506:Proteins; D014815:Vitamins; D009584:Nitrogen