Muscle strength particularity of Grand Tour cyclists from knee isokinetic assessment

Abstract

Summary Objectives To take part in a Grand Tour, the selection of the cyclists is not easy despite a link between isokinetic knee muscle strength and sprinting power. This study aimed to measure knee muscle strength among professional cyclists and to explore the difference in lower limb force between the rouleur/sprinter and the puncher/climber cycling tactic profiles. Materials and methods Thirty nine professional cyclists, who participated in at least one Grand Tour, were assessed at knee level with an isokinetic dynamometer. The relative peak torques normalised to the body mass at the 60, 180 and 240°/s angular speeds and the Limb Symmetry Index, were assessed. Four parameters of the Fatigue testing were studied: total work/kg of extensors and flexors, Fatigue slopes, breakpoint and angle. Results All knee extensors isokinetic parameters, excepted extensor LSI, were different between the 2 groups. The best prediction to identify rouleurs/sprinters was found with 2 parameters: knee extensors strength at 240°/s (Odd-ratios: 1440; P = 0.03) and extensors fatigue slope (ORs: 2.57; P = 0.02). The Receiver Operating Characteristic curves areas were respectively 0.851 and 0.840. Conclusion Isokinetic knee extensors strength and fatigue slope of rouleurs/sprinters are different from those of climbers/punchers. Isokinetic knee extensor's force could represent a new tool to select rouleurs/sprinters for a Grand Tour.