title: The effect of variable gradients on pacing in cycling time-trials.
abstract: It has been reported that performance in cycling time-trials is enhanced when power is varied in response to gradient although such a mechanical pacing strategy has never been confirmed experimentally in the field. The aim of this study was, therefore, to assess the efficacy of mechanical pacing by comparing a constant power strategy of 255 W with a variable power strategy that averaged to 255 W over an undulating time-trial course. 20 experienced cyclists completed 4 trials over a 4 km course with 2 trials at an average constant power of 253 W and 2 trials where power was varied in response to gradient and averaged 260 W. Time normalised to 255 W was 411±31.1 s for the constant power output trials and 399±29.5 s for the variable power output trials. The variable power output strategy therefore reduced completion time by 12±8 s (2.9%) which was significant ( P<0.001). Participants experienced difficulty in applying a constant power strategy over an undulating course which acted to reduce their time gain. It is concluded that a variable power strategy can improve cycling performance in a field time-trial where the gradient is not constant.
authors.affiliation: University of Brighton, Eastbourne, United Kingdom. p.cangley@brighton.ac.uk
authors.forename: P
authors.initials: P
authors.lastname: Cangley
authors.forename: L
authors.initials: L
authors.lastname: Passfield
authors.forename: H
authors.initials: H
authors.lastname: Carter
authors.forename: M
authors.initials: M
authors.lastname: Bailey
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D001696:Biomechanical Phenomena; D005843:Geography; D006801:Humans; D007700:Kinetics; D008297:Male; D015233:Models, Statistical; D005082:Physical Exertion / Q000502:physiology*; D013995:Time