VO2max is having a moment. Social media is full of promises to boost it in four weeks, and smart watches now estimate it from your wrist. But VO2max is only part of the fitness story. Cardiopulmonary exercise testing also measures CO2 production, respiratory exchange ratio, breath dynamics and heart rate, which show which fuel you are burning and when your body switches to anaerobic metabolism.
In our latest article on the VOCO website, we explain why VCO2 matters, how CPX systems are validated (and why comparing one device against another doesn’t tell you which is right), and what resting metabolic rate adds to the picture.