The Accuracy of the Progressive Aerobic Cardiovascular Endurance Run to Estimate Aerobic Fitness in Youth

Book excerpt: The FITNESSGRAM's Progressive Aerobic Cardiovascular Endurance Run (PACER) test is a commonly used field test to estimate peak oxygen uptake (VO2[subscript peak]) in youth. However, little research has been conducted to determine the influence of weight status on the accuracy of the equations used to estimate VO2[subscript peak]. Purpose: To assess the agreement between VO2[subscript peak] measured using indirect calorimetry during the PACER and estimated VO2[subscript peak] in normal weight and overweight youth and to determine the influence of weight status on the accuracy of estimated VO2[subscript peak] in 10-15 year old youth. Methods: The study included 101 participants that were classified as normal weight (n=78) or overweight (n=23) according to BMI percentiles for age and sex. Participants completed the PACER, a progressive, multistage, 20-meter shuttle run to volitional exhaustion. VO2[subscript peak] was measured during the PACER test using a portable gas analysis system (Oxycon Mobile, CareFusion, Inc.). Estimated VO2[subscript peak] values were calculated based on PACER performance using the Leger et al. and Mahar et al. equations. Paired samples t-tests were used to determine if significant differences existed between estimated and measured VO2[subscript peak]. Independent t-tests were performed to compare the normal weight and overweight groups. Accuracy was determined using Bland-Altman plots. Results: The Leger et al. (44.3 +̲4.6 ml·kg−1·min−1) and Mahar et al. (46.8 +̲4.8 ml·kg−1·min−1) estimated values were significantly lower than measured VO2[subscript peak] (49.1 +̲8.7 ml·kg−1·min−1) in the normal weight group. There were no significant differences between measured VO2[subscript peak] (38.8 +̲7.1 ml·kg−1·min−1) and predicted values (40.5 +̲2.5 and 38.2 +̲6.1 ml·kg−1·min−1 ; Leger et al. and Mahar et al., respectively) for the overweight group. For the normal weight group, the standard error of the estimate (SEE) was 5.44 ml·kg−1·min−1 (Leger) and 5.33 ml·kg−1·min−1 (Mahar). The SEE was 5.77 ml·kg−1·min−1 (Leger) and 4.54 ml·kg−1·min−1 (Mahar) for the overweight participants. Conclusions: It appears that the prediction of VO2[subscript peak] from either equation based on PACER performance varies among weight status group and may be inaccurate for normal weight youth, but acceptable for overweight youth.