Reliability of a 1-h endurance performance test in trained female cyclists

Abstract

Endurance performance is a common criterion used to evaluate training or dietary interventions. However, to accurately appraise the effects of an intervention, the endurance performance measure must be reliable. The purpose of the investigation was to establish the reliability of a 1-h endurance performance test. Twenty trained female subjects (peak VO2 = 47.4 +/- 7.2 ml.kg-1.min-1) completed two trials in which they had to generate the highest power output possible throughout 60 min of cycling. Heart rates (HR) and ratings of perceived exertion (RPE) were also recorded during these two trials. All tests were conducted on a wind-braked cycle ergometer set up to closely resemble the subject's own cycle. The trials were separated by 1 wk, conducted on the same day of the week, and completed at a similar time of the day. The average power outputs (+/-SD) for the two trials were 180.0 (+/-18.1) W and 180.0 (+/-20.6) W. The results revealed that average absolute power output, HR, and RPE were not significantly different between trials. The intraclass correlation coefficient (one way ANOVA) for average absolute power output was 0.97, the coefficient of variation was 2.7%, and the SEM was 3.4 W. These results suggest that under controlled conditions average absolute power output during a 1-h endurance test is a reliable measure for trained female cyclists.

Power output during women’s World Cup road cycle racing

“…Our data include the 1999 and 2004 World Cup winners and also, at times, the number one UCI ranked cycling nation in the world, thereby providing an insight into the power demands of some of the best contemporary female cyclists. The calibre of our riders ( _ V O 2peak ¼ 63.8±2.4 mL kg À1 min À1 ) is reinforced by comparable values for the US National Team (63.8±4.2 mL kg À1 min À1 : Wilber et al 1997) and women competing in the Tour of Idaho (64.2±3.9 mL kg À1 min À1 : Pfeiffer et al 1993), but are higher than data reported for an earlier US National Team (57.4±6.6 mL kg À1 min À1 : Burke 1980) and trained female cyclists (47.4±7.2 mL kg À1 min À1 : Bishop 1997). Previous investigations have estimated racing power output based on the HR-power output relationship established in the laboratory ).…”

Cycling time trial performance during different phases of the menstrual cycle

“…However, these significant changes to substrate metabolism in the luteal phase depend on the ratio of oestrogen to progesterone and the magnitude of the increase in oestrogen from follicular to luteal phase (D'Eon et al 2002), as well as nutritional status . Nonetheless, studies using time to exhaustion at a submaximal intensity are measuring endurance capacity (Bishop 1997) and this favours the metabolic profile associated with the luteal phase as suggested by the findings of some previous studies (Jurkowski et al 1981;Nicklas et al 1989), although not all (Biedleman et al 1999;Bailey et al 2000). Time trials are a better measure of exercise performance (Hickey et al 1992;Jeukendrup et al 1996) and demand greater proportions of carbohydrate oxidation to sustain the high intensity effort.…”

“…motivation, monotony and boredom) whereas a time trial has a fixed end point and thus reduces the impact of the psychological factors. Thus, time to exhaustion trials have poor test-retest reliability (coefficient of variation of $27%) (Jeukendrup et al 1996) compared to time trial protocols, which have a greater reproducibility (coefficient of variation of $1-3.4%) (Bishop 1997;Hickey et al 1992;Jeukendrup et al 1996;Palmer et al 1996). Hence, in this study we have chosen to measure performance by means of a cycling time trial.…”

The reliability of a simulated uphill time trial using the Velotron electronic bicycle ergometer

“…In broad terms, these tests either measure time to exhaustion at a given workload (Krebs and Powers 1989;Laursen et al 2003b;McLellan et al 1995), measure the time to complete a given amount of work (Hickey et al 1992;Jeukendrup et al 1996), measure the average work done during a given time frame (Bishop 1997;Coyle et al 1991), or the test is a simulated time trial (TT) in which the goal is to cover a given distance in as short a time as possible (Balmer et al 2000;Jensen and Johansen 1998;Palmer et al 1996;Schabort et al 1998;Smith et al 2001;Sporer and McKenzie 2007;Zavorsky et al 2007). Historically, the simulated time trials are accomplished by placing the subject's bicycle onto either an air or magnetically braked stationary trainer, and distance is measured by revolutions of the rear wheel.…”