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H S Klein

Publications and source records attributed to H S Klein.

6 recordsLinked to original sources
PubMed1987

Ventilatory threshold: measurement and variation with age.

The purpose of this study is to present measurement of ventilatory threshold (VeT) and maximal oxygen uptake (VO2max) in a large group of predominantly older subjects using a bicycle ergometer and an automated measuring system. One hundred and twenty-seven healthy elderly subjects (mean age: 68) and 44 young and middle-aged subjects (mean age: 39) underwent a maximal exercise test with breath-by-breath measurement of ventilation and gas exchange variables. Ventilatory threshold was determined by visual inspection of the breakpoints in the VE/VO2 and PETO2 data curves. Additional measures were made in a subset of subjects to determine the reproducibility and interobserver variability of VeT and the relationship between VeT and the venous lactate threshold (LaT). Day-to-day reproducibility of VeT was good with a mean difference in VO2 at VeT on two occasions of 40.23 +/- 125 ml/min. Interobserver variability was low (intraclass correlation coefficient of r = 0.941) and VeT was found to correlate to LaT (r = 0.79, P less than 0.05) with LaT occurring a mean 2.3 min after VeT. VeT declined significantly with age in both males and females but less rapidly than VO2max. Both VO2max and VeT were found to vary with age, sex, height, and weight in a stepwise multiple-linear regression analysis. Age-associated changes in skeletal muscle composition may be in part responsible for the less precipitous decline in VeT with age compared with VO2max.

Adult↗
PubMed1986

Exercise capacity in the elderly.

One of the primary manifestations of ageing is a reduced ability to respond to physiologic challenges. With aging, the ability to perform exercise and physical work declines and is reflected in the reduction in maximal oxygen consumption. Although this decline is influenced to some degree by the state of health and age, it seems that maintenance of regular physical activity significantly counteracts the loss of aerobic capacity. In healthy old age, the cardiovascular system is able to compensate for certain age-associated declines in cardiac function. A program of endurance training, even when begun in old age, can restore more youthful levels of physical fitness and results in tangible improvements in certain resting, submaximal and maximal indicators of exercise capacity. With comprehensive preexercise clinical screening, physical training can be conducted safely with minimal musculoskeletal problems in the aged. The long-term effects of exercise on morbidity, mortality and psychologic function in old age are unknown.

Adult↗