Pedalling rate affects endurance performance during high-intensity cycling

The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR−25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables, such as muscle fibre type composition and power reserve, relate to endurance time. Twenty males underwent testing to determine their maximal oxygen uptake (V̇O2max), power output corresponding to 90% of V̇O2max at 80 rpm (Ẇ90), FCPR at Ẇ90, percentage of slow twitch muscle fibres (% MHC I), maximal leg power, and endurance time at Ẇ90 with FCPR−25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. Ẇ90 was 325 (47) W. FCPR at Ẇ90 was 78 (11) rpm, resulting in FCPR−25 being 59 (8) rpm and FCPR+25 being 98 (13) rpm. Endurance time at Ẇ90FCPR+25 [441 (188) s] was significantly shorter than at Ẇ90FCPR [589 (232) s] and Ẇ90FCPR−25 [547 (170) s]. Metabolic responses such as V̇O2 and blood lactate concentration were generally higher at Ẇ90FCPR+25 than at Ẇ90FCPR−25 and Ẇ90FCPR. Endurance time was negatively related to V̇O2max, Ẇ90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables were of significance for endurance time, % MHC I showing a negative and power reserve a positive relationship.