Effect of cadence, cycling experience, and aerobic power on delta efficiency during cycling

To examine the influence of cadence, cycling experience, and aerobic power on delta efficiency during cycling and to determine the significance of delta efficiency as a factor underlying the selection of preferred cadence.

Delta efficiency (DE) was determined for 11 trained experienced cyclists (C), 10 trained runners (R), and 10 less-trained noncyclists (LT) at 50, 65, 80, 95, and 110 rpm. Preferred cadence (PC) was determined at 100, 150, and 200 W for C and R and at 75, 100, and 150 W for LT. Gas exchange at each power output (PO) was measured on a separate day, and the five cadences were randomly ordered on each occasion. It was hypothesized that: a) cyclists are most efficient at the higher cadences at which they are accustomed to training and racing, i.e., there will be a trend for DE to increase with increases in cadence; b) cyclists and runners will exhibit similar DE across the range of cadences tested; and c) DE of less-trained subjects will be lower than that of cyclists and runners.

PCs of C and R were similar and did not change appreciably with PO (100 W:C, 95.6 +/- 10.8; R, 92.0 +/- 8.5: 150 W:C, 94.4 +/- 10.3; R, 92.9 +/- 7.8: 200 W:C, 92.2 +/- 7.2; R, 91.8 +/- 7.9 rpm). The PC of LT was significantly lower and decreased with increases in power output (75 W: 80.0 +/- 15.3; 100 W; 77.5 +/- 15.1; 150 W; 69.1 +/- 11.9 rpm). The first hypothesis was rejected because analysis of the cyclists' data alone revealed no systematic increase in DE as cadence was increased [F(4,40) = 0.272, P = 0.894]. Repeated measures ANOVA on all three groups revealed no group x cadence interaction [F(8,112) = 0.589, P = 0.785]. Again there was no systematic effect of cadence on DE [F(4,112) = 1.058, P = 0.381]. The second and third hypotheses were also rejected since there was no group main effect, i.e., DE of cyclists, runners, and less-trained subjects were not significantly different [F(2,28) = 1.397, P = 0.264].

Pedaling cadence did not have a dramatic effect on DE in any group. Muscular efficiency, as measured indirectly by delta efficiency, appears to remain relatively constant at approximately 24%, regardless of cycling experience or fitness level.