A computer simulation of free-range exercise in the laboratory. Terblanche, E., J. A. Wessels, R. I. Stewart & J. H. Koeslag. Department of Medical Physiology and Biochemistry, University of Stellenbosch, P.O. Box 19063, Tygerberg, Cape Town, South Africa, 7505
APStracts 6:0271A, 1999.
We present a technique for simulating dynamic field (free-range) exercise, using a novel computer-controlled cycle ergometer. This modified cycle ergometer takes into account the effect of friction and aerodynamic drag forces for a 70 kg cyclist in a racing position. It also affords the ability of selecting different gear ratios. We have used this technique to simulate a known competition cycle route in Cape Town, South Africa. In an attempt to analyze the input stimulus, in this case the generated power output of each cyclist, 8 subjects cycled for 40 minutes at a self-selected, comfortable pace on the first part of the simulated route. Our results indicate that this exercise input excites the musculo-cardiorespiratory system over a wide range of power outputs, both in terms of amplitude and frequency. This stimulus profile thereby complies with the fundamental requirement for nonlinear (physiological) systems analysis and identification. Through a computer simulation we have devised a laboratory exercise protocol, which is not only physiologically real, but also overcomes the artificiality of most traditional laboratory exercise protocols.

Received 2 February 1998; accepted in final form 8 June 1999.
APS Manuscript Number A103-8.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 25 June 1999