Contributions of local and central sensations to the perception of exertion during cycling: effects of work rate and cadence.

There is evidence to suggest that perception of exertion during exercise is based on both local and central sensations. The aim of the present experiment was to determine the relative contributions of different sensations to overall perceived exertion during cycling. Eighteen trained cyclists pedalled on a cycle ergometer for 4 min at each of three work rates (100, 150 and 200 W) and cadences (50, 70 and 90 rev x min(-1)). At the end of each bout, they used Borg's category-ratio (CR-10) scale to rate their overall perceived exertion, leg muscle pain, knee pain, breathlessness and heart beat intensity. The results indicated that cadence only influenced local sensations (muscle pain and knee pain), which were significantly higher at slower pedalling rates. Neither overall perceived exertion nor central sensations (breathlessness and heart beat intensity) were significantly affected by cadence. In contrast, increases in work rate were associated with higher ratings for all sensations. Further analyses revealed that variations in these overall ratings of perceived exertion as a function of work rate were accounted for by variations in ratings of muscle pain and breathlessness. The general implication is that perceived exertion during cycling derives from a combination of muscle and respiratory sensations.