Affiliation:
1. Department of Health and Human Performance, Iowa State University, Ames, Iowa 50011
Abstract
Aging and chronic exercise training influence leg venous compliance. Venous compliance affects responses to an orthostatic stress; its effect on tolerance to maximal lower body negative pressure (LBNP) in the elderly is unknown. The purpose of this study was to determine the influence of age and fitness, a surrogate measure of exercise training, on calf venous compliance and tolerance to maximal LBNP in men and women. Forty participants, 10 young fit (YF; age = 22.6 ± 0.5 yr, peak oxygen uptake = 57.1 ± 2.0 ml·kg−1·min−1), 10 young unfit (YU; 23.1 ± 1.0 yr, 41.1 ± 2.0 ml·kg−1·min−1), 10 older fit (OF; 73.9 ± 2.0 yr, 39.0 ± 2.0 ml·kg−1·min−1), and 10 older unfit (OU; 70.9 ± 1.6 yr, 27.1 ± 2.0 ml·kg−1·min−1), underwent graded LBNP to presyncope or 4 min at −100 mmHg. By utilizing venous occlusion plethysmography, calf venous compliance was determined by using the first derivative of the pressure-volume relation during cuff pressure reduction. We found that the more fit groups had greater venous compliance than their unfit peers ( P < 0.05) as did the young groups compared with their older peers ( P < 0.05) such that OU < YU = OF < YF. LBNP tolerance did not differ between groups. In conclusion, these data suggest that aging reduces, and chronic exercise increases, venous compliance. However, these data do not support a significant influence of venous compliance on LBNP tolerance.
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Reference29 articles.
1. Effects of 18 days of bed rest on leg and arm venous properties
2. Physical fitness and cardiovascular response to lower body negative pressure
3. Blomqvist CG and Stone HL. Cardiovascular adjustments to gravitational stress. In: Handbook of Physiology. The Cardiovascular System. Peripheral Circulation and Organ Blood Flow. Bethesda, MD: Am. Physiol. Soc. 1983, sect. 2, vol. III, pt. 2, chapt. 28, p. 1025–1036.
4. Endurance exercise training
5. Convertino VA, Montgomery LD, and Greenleaf JE. Cardiovascular responses during orthostasis: effect of an increase in V̇o2 max. Aviat Space Environ Med 55: 702–708, 1984.
Cited by
39 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献