A single decreasing ramp friction sprint for torque-cadence relationship assessment in cycling

This study aimed to introduce and validate a novel method for assessing dynamic fatigue components through a single-sprint test, addressing the limitations of traditional multi-sprint evaluations.

We tested this method on twenty-one participants by computing torque-cadence relationships from two iso-friction sprints at varying friction levels (3% and 9% of body mass), the traditional combination of these iso-friction sprints and a novel decreasing ramp friction sprint ( ${\text{Fr}}_{\text{D}}$ ). The accuracy of this new method through fatigue was also tested with ten 6-s ${\text{Fr}}_{\text{D}}$ sprints interspersed with a 24-s passive rest.

${\text{Fr}}_{\text{D}}$ outperformed single iso-friction sprints and provided accurate and valid torque-cadence relationship's parameters estimates ( $T_{\text{0}}$ , $C_{\text{0}}$ , and $P_{\text{max}}$ ) with systematic bias < 3%, typical error of estimate < 6% and very high $r^2$ (median of 0.962). The quality of the input data from this method was also high, as evidenced by the well-distributed and wide-range cadence spectrum (51.3% of $C_0$ ; skewness = $-$ 0.51, $p<0.05$ ) and was maintained throughout the fatiguing exercise.

Our novel method not only allows the dynamic fatigue components evaluation with only one sprint but also maintains accuracy and validity across varying fatigue states, offering significant advantages for both research and practical applications.