Use of the force-velocity test to determine the optimal braking force for a sprint exercise on a friction-loaded cycle ergometer

Abstract

A group of 15 untrained male subjects pedalled on a friction-loaded cycle ergometer as fast as possible for 5-7 s to reach the maximal velocity (vmax) against different braking forces (FB). Power was averaged during a complete crank rotation by adding the power dissipated against FB to the power necessary to accelerate the flywheel. For each sprint, determinations were made of peak power output (Wpeak), power output attained at vmax (Wvmax) calculated as the product of vmax and FB and the work performed to reach vmax expressed in mean power output (Wvmax). The relationships between these parameters and FB were examined. A biopsy taken from the vastus lateralis muscle and tomodensitometric radiographs of both thighs were taken at rest to identify muscle metabolic and morphometric properties. The Wpeak value was similar for all FB. Therefore, the average of values was defined as corrected maximal power (Wmax). This value was 11% higher than the maximal power output uncorrected for the acceleration. Whereas the Wmax determination did not require high loads, the highest Wvmax value (Wmax) was produced when loading was heavy, as evidenced by the Wvmax-FB parabolic relationship. For each subject, the braking force (FB,Wmax) giving Wmax was defined as optimal. The FB,Wmax, equal to 0.844 (SD 0.108) N.kg-1 bodymass, was related to thigh muscle area (r = 0.78, P < 0.05). The maximal velocity (vm,Wmax) reached against this force seemed to be related more to intrinsic fibre properties (% fast twitch b fibre area and adenylate kinase activity). Thus, from the Wmax determination, it is suggested that it should be possible to predict the conditions for optimal exercise on a cycle ergometer.

Performance and fibre characteristics of human skeletal muscle during short sprint training and detraining on a cycle ergometer

“…The work output to reach a v max increased as the p B increased up to a given p B (Fig. 2) as has been described in a previous study (Linossier et al 1996). When expressed as vmax , individual force-mean power relationships were accurately described by a 2nd order polynomial regression as follows:…”

“…The work performed up to t vmax was calculated at each p B and has been expressed in mean power output ( vmax ) as follows: vmax total workat vmax The max was determined from the average of peak values recorded for dierent p B since peak was almost the same for all braking forces as has been shown in a previous study (Linossier et al 1996).…”

“…In a recent study we determined an optimal braking force (p BY W max ) for each subject from a force-velocity test (Linossier et al 1996). The maximal velocity reached against p BY W max v mY W max was correlated with the percentage FT b (%FT b ) area in untrained subjects.…”

Influence of two pedalling rate conditions on mechanical output and physiological responses during all-out intermittent exercise

“…Studies performed on an isokinetic (McCartney et al 1983) or friction-loaded cycle ergometer (Linossier et al 1996) confirmed pedalling rate to be the major factor governing the amount of work generated during a single sprint (5-s). The mechanical output is different for maximal exercises performed at different velocities; i.e.…”

Assessment of peak power and short-term work capacity

“…In retrospect, this absence of a difference can be explained by the fact that taking I into account permits detection of a relationship between torque applied to the flywheel and the angular velocity. This has been demonstrated by others Linossier et al 1996;Martin et al 1997). When the resistive load is less than optimal, the subject passes through the optimal torque-angular velocity combination on the way to peak velocity.…”