Billinger, SA, Loudon, JK, and Gajewski, BJ. Validity of a total body recumbent stepper exercise test to assess cardiorespiratory fitness. J Strength Cond Res 22(5):1556-1562, 2008-Maximum oxygen consumption (V̇o2max) is the primary measure for cardiorespiratory fitness, and the V̇o2max value achieved on the treadmill using the Bruce protocol is considered the gold standard. A novel exercise test using a total body recumbent stepper (TBRS) would be an alternative for measuring V̇o2max in healthy individuals. Furthermore, the TBRS exercise test (TBRS-XT) may be beneficial for individuals such as those with stroke, who cannot tolerate a treadmill or cycle ergometer test due to hemiparesis, increased tone in the extremities, or balance deficits. The purpose of the study was to assess the validity and reliability of the TBRS-XT in determining V̇o2max in healthy adults. Twenty-two healthy adults (9 women, 13 men; 26.9 ± 6.1 years of age) participated in 2 maximum exercise tests in random order. One exercise test was performed on the treadmill using the Bruce protocol and the other exercise test was the TBRS-XT. Statistical analysis of the data was conducted using simple linear regression where the response variable was the V̇o2max from the Bruce protocol and the predictor variable was the V̇o2max from the TBRS-XT. A 95% prediction interval was used to assess the strength of the prediction of V̇o2 from the Bruce protocol with R2 = 0.851. Preliminary data suggest that the TBRS-XT may be a valid test to predict V̇o2max when treadmill testing is not feasible. This would allow clinicians an alternative method for exercise testing and prescription to promote healthy lifestyle interventions for a variety of patient populations.