Principal Component Analysis of the Responses to Standard Exercise Training

Abstract

Common elements governing the responses to a standard programme of exercise ‘ training ’ have been investigated by the statistical technique of principal component analysis. Convergence of the data was checked by a pilot trial on a desk calculator and three definitive computer analyses were then carried out.

The first and second computer analyses were based on a wide range of measurements of pulse rate, respiratory minute volume, and personality. Six components accounted for 70 per cent of the variance of the data. These were tentatively identified as (i) cardiac response to exercise, (ii) resting state, (iii) ventilatory changes with training, (iv) and (v) influence of personality on resting state and exercise response, and (vi) body size. Components (i) and (v) were related to the subjects' initial physical fitness.

For the third computer analysis several measurements shown to be redundant were excluded and specific metabolic measurements were included. Six components then described 77 per cent of the variance. The initial metabolic cost of exercise was represented in components (i) and (ii) and changes with training in component (iv). Fitness was correlated most closely with the initial oxygen cost of exercise, and was also more closely related to pulse than to ventilatory measurements, and to results on Day 1 than to changes during training. Selection and weighting of parameters to yield an optimum objective assessment of physical fitness are discussed.

Additional information

Notes on contributors

R. J. SHEPHARD

Department of Physiological Hygiene, School of Hygiene, University of Toronto, Ontario, Canada.