Power output of track sprint cyclists

Abstract

The central aim of the present thesis was to address specific issues associated with the development and quantification of maximum power output produced by elite track sprint cyclists. The first study (Chapter 3) examined the accuracy of portable power monitoring devices for evaluating the power output of high performance cyclists. Although manufacturers of bicycle power monitoring devices claim accuracy to within 2.5%, there are limited scientific data available to support this. The accuracy of SRM and Power-Tap (PT) units was assessed under different experimental and environmental conditions. First, 19 SRMs were dynamically calibrated, raced for 11 months and retested using a dynamic CALRIG (50-1000 W@100 rpm). Second, using the same procedure, five PT units were repeatedly tested on alternate days. Third, the most accurate SRM and PT units were tested for accuracy at different cadences (60, 80, 100, 120 rpm), temperature (8 and 21 oC) and for drift over time (1hr@~300 W). Finally, data from the same SRM and PT units were downloaded and compared following random cadence and gear surges using the CALRIG and on a training ride. The accuracy of SRM and PT over a range of 50-1000 W was 2.3 p4.9% and -2.5 p 0.5%, respectively. A second set of trials provided more consistent results for 15 calibrated SRM units following 11 months (-0.8 p 1.7%) and follow-up testing of all PT units resulted in accuracy measures of -2.7 p 0.1%. Accuracy of the SRM and PT was not noticeably influenced by cadence or time, however, power output readings were influenced by temperature (5.2% for SRM and 8.4% for PT). During field trials, SRM average and maximum power outputs were 4.8% and 7.3% lower, respectively, compared to the PT values. The first study found that when operated according to the manufacturers' instructions, both SRM and PT offer the coach, athlete and sport scientist the ability to accurately monitor power output in the lab and the field. Calibration procedures matching performance tests (duration, power, cadence and temperature) are, however, advised as the error associated with each unit may vary.The purpose of the second study (described in Chapter 4) was to compare the maximum power output and pedaling rate relationships of World classnsprint cyclists during laboratory and field sprint cycling trials using dynamically calibrated SRM powermeters. The aim was to probe useful tools for assessing sprint cycling fitness, while also providing insight into skeletal muscle function by investigating the transferability of intrinsic muscle properties between varied conditions. Seven male (mean pSD; 180.0 p 3.0 cm; 86.2 p 6.1 kg) and four female (165.0 cm p 5.0 m; 62.9 p 3.9 kg) members of the Australian senior or under 19 yr track cycling teams performed maximal sprint cycling (l7 s) on a bicycle ergometer and a day later performed sprints of a similar duration on a velodrome. SRM powermeters were used to monitor power output and pedaling rate for all sprints. Data from each trial were analysed per revolution to establish the relationship between pedaling rate, torque and power output. Furthermore, linear torque and pedaling rate regression equations were used to calculate a predicted power output-pedaling rate relationship.n n n n n n n n n