[Significance of sports for the heart of the elderly].
The changes in performance of cardiopulmonary metabolic parameters during aging are discussed. With advancing age, maximal oxygen uptake, the aerobic-anaerobic threshold, maximal attainable pulse rate, maximal stroke volume, and maximal peak flow all decrease. The causes are a reduction in the windkessel function of the aorta, loss of elasticity in the arteries, and silting of the peripheral capillaries, as well as other unidentified factors. The lower the aerobic-anaerobic threshold, the greater the reduction in blood flow through the liver and kidneys at given levels of load. This applies particularly to older individuals. The pulmonary circulation increases in inverse proportion to the maximal oxygen uptake value at submaximal load. Cerebral blood flow increases highly significantly in all parts of the left hemisphere at a measured work load of only 25 W, and the further increase at 100 W is again significant. The increase is greater in the gray matter than in the white matter. The maximal minute volume under load runs parallel to the maximal oxygen uptake curve with increasing age. Simultaneously, maximal diffusion capacity decreases and there is a reduction in the quality of distribution and perfusion. The result is an age-related decline of partial oxygen pressure in arterial blood. With advancing age there is an earlier rise in blood catecholamine levels, whereas the density of adrenoreceptors apparently changes only slightly, although their sensitivity decreases. Essentially, 55- to 70-year-old subjects who have gone for decades with no training are as trainable as untrained subjects in the third decade of life. This is true for all the parameter mentioned above. In contrast to younger subjects, muscle biopsies show an increase in activity not only of oxidative enzymes, but also of anaerobic enzymes (e.g., LDH). There is no increase in heart size after 8-12 weeks training. At rest and at given loads, there is an increase in stroke volume accompanied by a reduction in heart rate; peripheral resistance also decreases significantly. The heart of an older person participating in active sport could be placed at risk by inadequate training, but possibly also by excessive demands on intensity and duration.
D000368:Aged; D000375:Aging; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D003326:Coronary Circulation; D004798:Enzymes / Q000378:metabolism; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000201:enzymology; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010807:Physical Endurance; D012306:Risk; D013177:Sports
D004798:Enzymes
Die Bedeutung des Sports für das Herz des ältern Menschen.