If you’re on a mission to live longer, experts say there’s one metric worth paying attention to: VO2 max. With the rise of wearable technology (and a growing obsession with tracking our health), VO2 is now something many of us are monitoring. So much so that Google searches for “improving VO2 max” have skyrocketed by more than 5,000% in the past year alone. “A high VO2 max is strongly linked to better cardiovascular and metabolic health, improved glucose regulation, and a longer lifespan. Conversely, low VO2 max is considered a stronger predictor of mortality risk than smoking, obesity, high blood pressure, and type 2 diabetes.