The process of fatigue during 30 s of high-intensity exercise results in rapid and substantial mechanical, electrical and biochemical changes in muscle fibres. This thesis describes a series of experiments, performed upon a friction-loaded cycle ergometer, which investigated whether the magnitude of the mechanical and biochemical changes is affected by changes in average pedalling rate. The ability to generate peak power in a subsequent sprint of 6 s duration was used to assess the magnitude of the mechanical changes. Changes in the concentrations of blood and muscle metabolites pre- and post-exercise permitted some of the biochemical changes to be measured.