Introduction:

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.

Methods:

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.

Results:

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).

Conclusions:

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.