The physiology of the pursuit cycle race

The principal aim of this thesis was to develop a greater understanding of the physiological mechanisms underlying performance in the individual pursuit cycle race. Three separate topics were addressed: The suitabi!lty of various laboratory measures of physiological function, the relationship between pursuit performance and selected physiological indices, and the longitudinal training responses of pursuit cyclists. The aerobic power of national squad pursuit cyclists was assessed in two ways. VOzmax was measured on a specially modified ergometer using a protocol optimized for cyclists. Submaximal ·blood lactate responses to incremental were evaluated with the 4 mmol.l-1 lactate threshold measure, A pilot study on 11 cyclists found this to be a accurate index of the maximum power output that could be sustained under true steady state conditions. No suitable test of anaerobic power could be found so this variable was not directly measured. Performance in the 1987 British Championships was correlnted with laboratory data measured just prior to competition for 9 pursuit cyclists. Significant relationships were found between race speed and absolute values of VOzmax (r = 0.63, p<0.05), and Power output at 4 mmol.l-1 lactate (r = 0.93, p<0.01). However, when these variables were related to body mass, body mass-o·667 or body surface area reduced correlations were observed. No relationship between post race blood lactate levels and performance was found. It was concluded that pursuit racing performance is primarily limited by the metabolic acidosis arising from the failure to deliver sufficient oxygen to the mitochondria of the exercising musculature. At elite levels of competition, heavier cyclists appear to possess an advantage over their lighter rivals due to a higher absolute work capacity. The measurement of power output at 4 mmol.l-1 lactate was found to be the most appropriate measure of pursuit performance potential, and the most sensitive index of long term training responses in competitive cyclists.This thesis is the result of an attempt to Integrate two challenges which have fascinated me for some time, the quest for sporting excellence and the search for a greater knowledge of the mechanisms underlying human performance. Although humble in its goals and limited in its conclusions this work nevertheless represents the achievement of an important personal goal, one that could not have been contemplated, much less attempted without the continuous support and inspiration of one man. It Is therefore with a deep sense of personal gratitude that I dedicate this thesis to Gordon Wright, a revered friend and educator.