Effects of crank length on cycling efficiency, sprint performance, and perceived fatigue in high-level amateur road cyclists

Abstract

Purpose

This study aimed to evaluate the effects of three different crank lengths (165 mm, 170 mm, and 175 mm) on cycling efficiency, sprint performance, and perceived fatigue in high-level amateur road cyclists.

Methods

A single-blind, randomized crossover design was employed, involving 28 trained male cyclists who completed three trials, each using a different crank length. Performance metrics, cycling economy (CE) including 20-min cycling under 60 % VO_2MAX, peak and average power during a 6s sprint, cadence, heart rate, and perceived exertion, were measured using validated ergometers and metabolic analyzers.

Results

The results indicated significant differences in 60 %VO_2MAXRPE were observed between the 165 mm and 175 mm cranks (p < 0.001, δ = −0.72) and between the 175 mm and 170 mm cranks (p < 0.001, δ = −0.67). In contrast, no significant difference was observed between the 165 mm and 170 mm cranks (p = 0.25, δ = −0.17). For 60 %VO_2MAX, 6sMaxPower, 6sAVPower, 6sAVRpm, CE, 60 %VO_2MAXAVHeart, 6sMaxRpm no significant differences were observed between any of the crank length groups (p > 0.34).

Conclusion

For high-level amateur road cyclists, using a 165 mm or 170 mm crank reduces subjective fatigue compared to a 175 mm crank, influencing affecting cycling efficiency or sprint performance. These findings help refine crank length recommendations to optimize performance, reduce injury risk, and improve comfort for high-level amateur road cyclists.