Fatigue-Free Force-Velocity and Power-Velocity Profiles for Elite Track Sprint Cyclists: The Influence of Duration, Gear Ratio and Pedalling Rates

Abstract

Background: Maximal force-velocity (F/v) profiles for track cyclists are commonly derived from ergometer sprints using an isovelocity or isoinertial approach. Previously, an attempt was made to derive maximal F/v profiles from a single maximal 65-m sprint on the cycling track. Hypothesising that this approach may not accurately reflect the fatigue-free F/v profile, we propose an alternative procedure and compare it to the previous method. Moreover, we test for the impact of gear ratio on diagnostic results. Methods: Twelve elite track cyclists completed a high-cadence low-resistance pedalling test on a freestanding roller (motoric test) and two series of three maximal 65-m sprints on a cycling track with different gear ratios. F/v profiles were calculated based on the measured crank force and cadence either during the first 6–7 revolutions (≤6 s) on the track (model I) or were derived from the first 3–4 revolutions (≤3 s) on the track combined with 1 or 2 fatigue-free cycles at cadences above 160 rpm from the motoric test (model II). Results: Although both models exhibit high-to-excellent linearity between force and velocity, the extrapolated isometric force was higher (1507.51 ± 257.60 N and 1384.35 ± 276.84 N; p < 0.002; d = 2.555) and the slope steeper ( and ; p < 0.003, d = −2.401) with model I. An ICC of 1.00 indicates excellent model consistency when comparing the F/v profiles (model II) derived from the different geared sprints. Conclusions: Assuring fatigue-free measurements and including high-cadence data points in the calculations provide valid maximal F/v and P/v profiles from a single acceleration-sprint independent of gear ratio.

The Concept of Optimal Dynamic Pedalling Rate and Its Application to Power Output and Fatigue in Track Cycling Sprinters—A Case Study

“…The gear ratio chosen was 3.87:1 (58/15), corresponding to a deployment of 8.12 m. Pedal force and crank velocity were measured continuously during the warm-up and the race with a power meter (FES, Institute for Research and Development of Sports Equipment, Berlin, Germany) recording the tangential force on the crank with a sampling frequency of 200 Hz and the duration of each crank revolution. This system allows for the creation of sport-specific F/v and P/v profiles [ 6 ]. Raw data was exported and further processed in Office Excel 2016 (Microsoft Corporation, Redmond, WA, USA).…”

“…Previous studies have shown that cycling in a standing position can increase power output by 8–12%, which has been attributed to additional power development from the upper body [ 25 , 26 , 27 , 28 ]. To accurately analyse the race data and to calculate the fatigue-induced changes in optimal cadence, separate fatigue-free F/v and P/v profiles were created for a standing and a seated position on the bike, as described in a previous publication [ 6 ].…”

“…A decisive physiological determinant of performance in track cycling sprints is the neuro-muscular capacity, i.e., the ability to produce high fatigue-free power output, which can be described by maximal force–velocity (F/v) and power–velocity (P/v) profiles [ 1 , 4 , 5 , 6 ]. Hill [ 7 ] modelled the velocity of the shortening of single muscle fibres as a rectangular hyperbola, but in multi-joint movements with resistance a strong linear relation between the force generated and velocity of movement has been established as standard model [ 8 , 9 ].…”

“…In cycling, the F/v relationship of mean pedal force and pedalling rate (PR) was identified as linear and, consequently, the relationship between power output (P) and pedalling rate as parabolic. Both can be derived from short maximal sprints in laboratory and in field [ 5 , 6 , 10 , 11 , 12 , 13 , 14 ].…”

“…In track cycling, valid maximal F/v and P/v profiles can be derived from fatigue-free maximal accelerations with sufficiently wide cadence spectra [ 6 ]. The functions established can be used to extra- and interpolate parameters as the current maximal mean pedal force (F max ) , maximal pedalling rate (PR max ), maximal power output (P max ) and current optimal pedalling rate (PR opt ) corresponding to P max [ 5 , 6 , 15 ].…”