Reliability of Mean Power Recorded During Indoor and Outdoor Self-Paced 40 km Cycling Time-Trials

The purpose of this study was to assess reliability of both indoor and outdoor 40 km time-trial cycling performance. Eight trained cyclists completed three indoor 40 km time-trials on an air-braked ergometer (Kingcycle^TM) and three outdoor 40 km time-trials on a local course. Power output was measured for all trials using the SRM™ powermeter. Mean performance time across three indoor trials was 54.21 ± 2.59 (min : sec) and was significantly different (P < 0.05) to mean time across three outdoor trials (57.29 ± 3.22 min : sec). However, there was no significant difference (P = 0.34) for mean power across three indoor trials (303 ± 35 W) when compared to outdoor performances (312 ± 23 W). Within-subject variation for mean power output expressed as a coefficient of variation (CV) improved in both indoors and outdoors for trials 2 and 3 (CV = 1.9 %, 95 % CI 1.0 - 3.4 and CV = 2.1 %, 95 % CI 1.1 - 3.8) when compared to trials 1 and 2 (CV = 2.1 %, 95 % CI 1.2 - 3.8 and CV = 2.4 %, 95 % CI 1.3 - 4.3). These findings indicate that power output measured using the SRM powermeter is highly reproducible for both laboratory-based and actual 40 km time-trial cycling performance.

Key words:

Cycling performance, reproducibility, SRM powermeter, fixed-distance.

References

• 1 Balmer J, Davison R CR, Coleman D A, Bird S R. The validity of power output recorded during exercise performance tests using a Kingcycle air-braked ergometer when compared with an SRM powermeter.  Int J Sports Med. 2000;  21 195-199
• 2 Balmer J, Davison R CR, Bird S R. Peak power output predicts performance power during an outdoor 16.1 km cycling time-trial.  Med Sci Sports Exerc. 2000, in press; 
• 3 Bishop D. Reliability of a 1 h endurance performance test intrained female cyclists.  Med Sci Sports Exerc. 1997;  29 554-559
• 4 Burke E D, Pruitt A L. Body positioning for cycling. In: Burke ED (ed) High-Tech Cycling. Champaign, Illinois; Human Kinetics 1996
• 5 Davison R CR, Coleman D A, Balmer J, Nunn M, Theakson S, Burrows M, Bird S R. Assessment of blood lactate: A practical evaluation of the biosen 5030 lactate analyser.  Med Sci Sports Exerc. 2000;  32 243-247
• 6 Hickey M S, Costill D L, McConell G K, Widrick J J, Tanaka H. Day to day variation in time-trial cycling performance.  Int J Sports Med. 1992;  13 467-470
• 7 Hopkins W G. Reliability of competitive performance of elite track-and-field athletes (Abstract). Australia; IOC World Congress of Sport Sciences 1999: 13
• 8 Hopkins W G, Paton C D. Reliability of performance of elite male athletes competing in international Olympic triathlons (Abstract). Australia; IOC World Congress of Sport Sciences 1999: 13
• 9 Hopkins W G, Hawley J A, Burke L A. Design and analysis of research on sport performance enhancement.  Med Sci Sports Exerc. 1998;  31 472-485
• 10 Jeukendrup A, Saris W H, Brouns F, Kester AD. A new validated endurance performance test.  Med Sci Sports Exerc. 1996;  28 266-270
• 11 Jeukendrup A, van Diemen A. Heart rate monitoring during training and competition in cyclists.  J Sports Sci. 1998;  16 S91-S99
• 12 Jones S A, Passfield L. The dynamic calibration of bicycle power measuring cranks. In: Haake SJ (ed) The Engineering of Sport. Oxford; Blackwell Science 1998: 265-274
• 13 Martin J C, Milliken D L, Cobb J E, McFadden K L, Coggan A R. Validation of a mathematical model for road cycling power.  J Appl Biomech. 1998;  14 277-291
• 14 Maughan R. Carbohydrate feeding before and after exercise. In: Lamb DR, Williams MH (eds) Perspectives in Exercise Science and Sports Medicine. Ergogenics: Enhancement of performance in Exercise and Sport 1991 4: 35-86
• 15 McLellan T M, Cheng S S, Jacobs I. Variability of time to exhaustion during submaximal exercise.  Can J Appl Physiol. 1995;  20 39-51
• 16 Neary J P, Bell G J, Quinney H A. Reproducibility in simulated 40 km time trial cycling and its associated metabolic stress.  Sports Med Training and Rehab. 1999;  9 79-88
• 17 Palmer G S, Dennis S C, Noakes T D, Hawley J A. Assessment of the reproducibility of performance testing on an air-braked cycle ergometer.  Int J Sports Med. 1996;  17 293-298
• 18 Palmer G S, Clancy M C, Hawley J A, Rodger I M, Burke L M, Noakes T D. Carbohydrate ingestion immediately before exercise does not improve 20 km time-trial performance in well trained cyclists.  Int J Sports Med. 1998;  19 415-418
• 19 Road Time-trials Council, Handbook. Ashford UK; Geerings 1999: 77-109
• 20 Schabort E J, Hawley J A, Hopkins W G, Mujika I, Noakes T D. A new reliable laboratory test of endurance performance for road cyclists.  Med Sci Sports Exerc. 1998;  30 1744-1750
• 21 Schabort E J, Hopkins W G, Hawley J A. Reproducibility of self-paced treadmill performance of trained endurance runners.  Int J Sports Med. 1998;  19 48-51
• 22 Seiler K S, Spirduso W W, Martin J C. Gender differences in rowing performance and power with aging.  Med Sci Sports Exerc. 1998;  30 121-127
• 23 Sherman W M. Nutrition for Cycling. In: Burke ED (ed) High-Tech Cycling. Champaign, Illinois; Human Kinetics 1996: 185-206
• 24 Tate R F, Klett G W. Optimal confidence for the variance of a normal distribution.  J Am Stat Ass. 1959;  54 674-682