Author(s): BURT, D., JONES, S., PHEASEY, C., BUCKLEY, J., Institution: KEELE UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 1995

INTRODUCTION:
Maintaining and assessing aerobic fitness (VO2max) is important for health, longevity, and ascertaining suitability to work and undergo medical treatment. The Chester Step Test (CST) is a safe, inexpensive, and popular, submaximal exercise test capable of predicting VO2max from the assumed linear relationship between exercise intensity, heart rate (HR), and oxygen uptake; however, its accuracy is questionable (1). To overcome previous limitations, a modified version (CST2) that follows the same procedures as the traditional method (CST1) with the exception that HR is recorded every minute, has recently been developed (2). The additional HR data is claimed to provide a more accurate prediction of VO2max (3), however, to date, no research has confirmed if the CST2 provides a more accurate prediction of VO2max when compared against the CST1.
METHODS:
Fifty healthy participants (18 females, 32 males) completed the CST1, the CST2, and a treadmill-based VO2max test. Tests were conduced in a randomised order, at the same time of day, in similar environmental conditions, and with at least 24 hours rest between trials. Systematic measurement bias across all three trials (CST1, CST2, and VO2max) was examined using a repeated measures ANOVA. Validity of the CST1 and CST2 predicted VO2max were further examined using the 95% limits of agreement (95% LoA = bias ± 1.96 x SDdiff).
RESULTS:
Mean ± SD of the CST1 and CST2 predicted VO2max, and actual VO2max were 42.9 ± 7.9, 42.9 ± 7.6, and 41.8 ± 7.4 ml.kg-1.min-1, respectively. No significant bias was shown between the CST1 and CST2 predicted VO2max and actual VO2max (P > 0.05). The 95% LoA between the CST1 predicted VO2max and actual VO2max and the CST2 predicted VO2max and actual VO2max were similar (1.04 ± 10.7 ml.kg-1.min-1 and 1.08 ± 11 ml.kg-1.min-1, respectively), translating to 28% and 29% prediction error in the worst case.
CONCLUSION:
Despite claims that the collection of additional HR data during the CST2 provides a more accurate prediction of VO2max (3), findings from the current study reveal no difference between the estimation of VO2max obtained from the CST1 or CST2. Provided the same version is used during repeated trials, either test can be used to provide an estimation of VO2max.

1. Buckley JP, Sim J, Eston RG, Hession R, Fox R. (2004). Reliability and validity of measures taken during the Chester step test to predict aerobic power and to prescribe aerobic exercise. Br J Sports Med, 38, 197–205. https://doi.org/10.1136/bjsm.2003.005389

2. Sykes K. (2019). Chester step test 2. Cartwright Fitness.

3. Sykes K. (2020). Chester step test 2 – an online submaximal test for the assessment of aerobic capacity (VO2max). EC Pulmonol and Respir Med, 9(3), 01–03