Definition
VO2 max measures the peak rate your body can absorb and use oxygen, in ml/kg/min. It's the gold-standard marker of cardiovascular fitness and one of the strongest predictors of all-cause mortality. Zone 2 work raises the floor; HIIT raises the ceiling.
Real questions
How do I improve VO2 max?
Combine 2–3 Zone 2 sessions per week with 1 HIIT session (e.g. 4×4 minutes hard, 3 minutes easy). Most people add 5–10 points in 12 weeks.
Stack with
Put it to work
Coach Foster builds your program around vo2 max and the rest of the fundamentals, shaped to your body and your week.