Non-circular chainring improves aerobic cycling performance in non-cyclists |
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Authors: | Frédérique Hintzy Nicolas Horvais |
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Institution: | Exercise Physiology Laboratory, University of Savoy Mont-Blanc, Bourget du Lac, France |
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Abstract: | Non-circular chainrings alter the crank velocity profile over a pedalling cycle. The aim of this study was to investigate the effect of this altered crank velocity profile on the aerobic performance compared to a circular chainring (CC). Ten male non-cyclists performed two incremental maximal tests at 80?rpm on a cycle ergometer: one with a circular (Shimano) and the other with a non-circular chainring Osymetric® (Somovedi), at least 50?h apart. Each test started with a workload of 100?W lasting 3?min. During the first 12?min, the workload was increased by 30?W every 3?min. Thereafter, the workload was increased by 30?W every 2?min until exhaustion. The power output, the intra-cycle crank angular velocity and the physiological parameters were monitored continuously, averaged over the last 30?s of each increment and at exhaustion, and compared for the two chainrings. Results showed a higher maximal aerobic power attained with the non-circular chainring (362.6?±?37.9 vs. 338.8?±?32.6?W, p?.001; moderate effect), which could be explained by a significantly lower energy expenditure during the first increment at 100?W. It could be hypothesised that the use of the non-circular chainring allowed saving a small part of energy expenditure throughout the test, allowing the exhaustion of the subject at a higher increment for a similar maximal energy expenditure, in comparison with a CC. Although this improvement is obtained only for non-cyclists, it allowed highlighting the link between cycling equipment modifying the pedalling motion and physiological responses. |
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Keywords: | Technology biomechanics performance fatigue |
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