VO2max is the maximum amount of oxygen your body can take in and use during exercise. Think of it as the ceiling of your aerobic engine. Your thresholds and your race pace sit somewhere underneath it, so raising the ceiling gives everything below it more room to grow.
What limits VO2max?
VO2max depends mainly on how much oxygen-rich blood your heart can pump each minute, and how well your muscles can extract and use that oxygen. Both respond to training, especially to well-placed high-intensity work.
What VO2max sessions look like
The goal is to spend meaningful time close to your maximal oxygen uptake. Common formats include:
- 4 to 6 intervals of 3 to 5 minutes at a hard, sustainable effort (about the pace or power you could hold for 6 to 8 minutes all-out), with roughly equal recovery
- Shorter repeats such as 30 seconds hard, 15 seconds easy, in sets of 8 to 13, which accumulate time at a high oxygen uptake
These sessions are demanding. Quality matters more than quantity.
How often?
For most endurance athletes, one VO2max session a week during the right training block is enough, alongside plenty of easy aerobic work. Two a week can work for short periods for experienced athletes, but recovery has to be managed carefully.
When does it fit in the season?
VO2max work is especially useful:
- Early in a build, to lift your ceiling before more race-specific training
- For athletes whose thresholds are already close to their VO2max and have little room to rise
- In shorter, faster events where high-end power and pace matter
For ultra-distance athletes, it still has a place, but it sits alongside a much larger volume of easy and steady training.
Common mistakes
- Going too hard on the first interval and fading on the rest
- Doing VO2max sessions when you're already fatigued
- Adding them on top of a week that's already full of hard sessions
