Power variation strategies for cycling time trials: A differential equation model

Abstract In cycling time trials, competitors aim to ride a course in the fastest possible time and the implementation of a pacing strategy is therefore essential. In this study, a differential equation model of a cyclist incorporating continuous changes in velocity is formulated and applied to a selection of theoretical courses and athletes. The model is augmented with a constraint corresponding to a mean work rate and various pacing strategies are considered. The inclusion of continuous accelerations experienced by the cyclist forms an essential component in a model for courses comprising many changes of gradient, and a steady-state approximation, which has previously been used to assess pacing strategies, is not suitable. In addition to formulating a result on the mathematically optimal solution of the model equations subject to the mean power constraint, it is also shown that substantial time savings can be realized by cyclists increasing their work rates on uphill sections and suitably reducing their work rates elsewhere. However, the amount of time saved is highly course- and athlete-dependent with the greatest gains arising on courses with the longest continuous ascents by cyclists of greatest mass.

[1]  G. Atkinson,et al.  Variable versus constant power strategies during cycling time-trials: Prediction of time savings using an up-to-date mathematical model , 2007, Journal of sports sciences.

[2]  S Olive,et al.  Modeling road-cycling performance. , 1995, Journal of applied physiology.

[3]  R. Hugh Morton,et al.  On a model of human bioenergetics , 2004, European Journal of Applied Physiology and Occupational Physiology.

[4]  G Atkinson,et al.  Pacing strategies during a cycling time trial with simulated headwinds and tailwinds , 2000, Ergonomics.

[5]  R. Hugh Morton,et al.  The critical power and related whole-body bioenergetic models , 2006, European Journal of Applied Physiology.

[6]  N P Craig,et al.  Mathematical model of cycling performance. , 1993, Journal of applied physiology.

[7]  David P. Swain,et al.  Physiological effects of constant versus variable power during endurance cycling. , 1998 .

[8]  R. Tucker,et al.  The anticipatory regulation of performance: the physiological basis for pacing strategies and the development of a perception-based model for exercise performance , 2009, British Journal of Sports Medicine.

[9]  D. Swain,et al.  Physiological effects of constant versus variable power during endurance cycling. , 1998, Medicine and science in sports and exercise.

[10]  T D Noakes,et al.  Heart rate responses during a 4-d cycle stage race. , 1994, Medicine and science in sports and exercise.

[11]  T D Noakes,et al.  Experimental evaluation of the power balance model of speed skating. , 2005, Journal of applied physiology.

[12]  David T. Martin,et al.  Modeling sprint cycling using field-derived parameters and forward integration. , 2006, Medicine and science in sports and exercise.

[13]  James C Martin,et al.  Validation of a Mathematical Model for Road Cycling Power. , 1998, Journal of applied biomechanics.

[14]  R. H. Morton,et al.  Modelling human power and endurance , 1990, Journal of mathematical biology.

[15]  Scott Gordon,et al.  Optimising distribution of power during a cycling time trial , 2005 .

[16]  M. Schrager,et al.  Effect of pacing strategy on cycle time trial performance. , 1993, Medicine and science in sports and exercise.

[17]  R. W. Bullard,et al.  Influence of fatigue on the efficiency of men during exhausting runs. , 1958, Journal of applied physiology.

[18]  G Cortili,et al.  Equation of motion of a cyclist. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[19]  D. Swain A model for optimizing cycling performance by varying power on hills and in wind. , 1997, Medicine and science in sports and exercise.

[20]  Alain Belli,et al.  Aerodynamic drag in field cycling with special reference to the Obree's position , 1997 .

[21]  L Passfield,et al.  The Effect of Variable Gradients on Pacing in Cycling Time-Trials , 2010, International journal of sports medicine.