Sport scientists and researchers often use laboratory-based tests to monitor competitive cyclists and to investigate training strategies and other interventions that might provide a worthwhile enhancement in performance. The series of studies in this thesis ain to: (1) provide an understanding of major issues related to test error when monitoring competitive cyclists using performance tests; (2) determine the magnitude of the smallest worthwhile enhancements in performance that matters to competitive cyclists; (3) evaluate experimentally the efficacy of a novel training intervention with competitive cyclists.