Strength capacity of lower-limb muscles in world-class cyclists: new insights into the limits of sprint cycling performance

ABSTRACT

This study aimed to determine the relationship between the torque-generating capacity in sprint cycling and the strength capacity of the six lower-limb muscle groups in male and female world-class sprint cyclists. Eleven female and fifteen male top-elite cyclists performed 5-s sprints at maximal power in seated and standing positions. They also performed a set of maximal voluntary ankle, knee and hip flexions and extensions to assess single-joint isometric and isokinetic torques. Isokinetic torques presented stronger correlations with cycling torque than isometric torques for both body positions, regardless of the group. In the female group, knee extension and hip flexion torques accounted for 81.2% of the variance in cycling torque, while the ability to predict cycling torque was less evident in males (i.e., 59% of variance explained by the plantarflexion torque only). The standing condition showed higher correlations than seated and a better predictive model in males (R² = 0.88). In addition to the knee extensors and flexors and hip extensors, main power producers, the strength capacity of lower-limb distal plantarflexor (and to a lesser extent dorsiflexor) muscles, as well as other non-measured qualities (e.g., the upper body), might be determinants to produce such extremely high cycling torque in males.

KEYWORDS:

• Single-joint torque
• multi-joint task
• maximal voluntary contraction
• maximal power output
• top-level performance
• muscle coordination

Acknowledgments

The authors thank the SEP Laboratory (EA 7370) for hosting the experiments and Anthony Baré, Lilian Lacourpaille, Simon Avrillon and Julien Lardy for their assistance during these experiments. The authors are also grateful to all the elite athletes for their participation in the experiments, to the national head coaches in track and BMX sprint cycling and to Emmanuel Brunet, the research and performance manager of the French Cycling Federation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was partly funded by the French Ministry of Sport (project 14_R_23). I. Sachet was supported by the French Ministry of Research and Innovation and National Association of Research and Technology (ANRT) via a CIFRE convention with the French Cycling Federation.