1. Polk, Donna M. MD, MPH

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VO2 testing provides an accurate measure of aerobic fitness, however utilization is limited due to availability and expense of a metabolic cart testing. The NewLeaf VO2 testing system is a commercially available portable gas exchange measurement system. We comparatively tested the NewLeaf VO2 system against metabolic cart testing.



20 healthy men and women volunteers were randomized to undergo maximal VO2 testing using a Medical Graphics Cardio O2 metabolic cart, or New Leaf VO2 testing system, using a modified Bruce protocol. A repeat maximal VO2 test was then performed on the alternate system within 8 days of the first one to reduce training effects.



Overall, 65% of participants were female, average age was 36.2 yrs, and BMI of 26.9 kg/m2. The mean difference in VO2 max between tests was 0.805 ml/min (SD +/- 6.27). The intra-class correlation coefficient was 0.81 (P <.0001). Measured VO2 over time by both systems is seen in figure below. A nonsignificant trend towards a variation in VO2 max between systems was observed among premenopausal women (83%) compared to post-menopausal women (17%) and men combined (P +.11).



New Leaf VO2 testing system measures max VO2 with high precision and validity compared to metabolic cart testing. These results support the use of the NewLeaf VO2 testing system in a variety of settings.