Muscle metabolites, force, and perceived exertion bicycling at varying pedal rates

Muscle metabolites, force, and perceived exertion bicycling at varying pedal rates. Med. Sci. Sports Exercise, Vol 12, No. 5, pp. 345-351, 1980. The relative significance of central (VE, Vo2, heart rate) or peripheral (muscle tension, muscle metabolites) factors on perceived exertion (RPE) was investigated with bicycle exercise by varying pedal rate while maintaining a constant power output. Six healthy male subjects exercised at zero load, submaximal (70% Vo2max) and maximal exercise intensities with pedal rates of 40, 60, 80, and 100 rpm. With changing pedal rate and constant power output, there were numerous examples of significant changes in the central factors with no change in RPE and vice versa. Similarly, measures of muscle and blood lactate, NAD, glycogen, ATP, and CP failed to demonstrate any local metabolic factor that correlated with RPE. Force exerted on the pedals and the rate of force generation approximated RPE changes, but the detailed correlation analysis was nonsignificant. None of the central or peripheral factors alone are related to RPE. Thus, RPE must be derived from a number of peripheral and/or central factors in a complex manner.