What VO2 Max Actually Is
VO2 max is the maximum amount of oxygen your body can use during intense exercise, measured in milliliters of oxygen per kilogram of body weight per minute. In plain English: it's a measure of your aerobic fitness — how efficiently your cardiovascular and respiratory systems deliver oxygen to your muscles, and how efficiently your muscles use it. Your aerobic system is the foundation of distance running — the ability to take in, transport, and use oxygen is what determines whether you can hold a pace for three hours without falling apart.
What VO2 Max Doesn't Tell You
Whether you're mentally tough
Whether you'll PR your next race
How good your fueling strategy is
Whether you have enough long-run mileage
Whether you did the workout "right"
It's one data point, not a verdict. Some athletes with lower VO2 max numbers crush marathons because they've built massive aerobic capacity and economy of effort; some with high VO2 max numbers struggle because they don't have the mileage base. Useful data, not a grade.
How to Estimate Yours (Free, No Lab Required)
The test: warm up 10 minutes warm up (conversational pace), then stop to catch your breath and get focused. THEN, mile time trial. 1600m hard all out effort. The goal is to run smart, confident, and finish knowing you have nothing left. Catch your breath and then cool down for 10 minutes at that same conversational pace (slow, strong and steady).
The math: Take that mile time trial time and head to the training paces part of the app. You’ll find the V.02 calculator under Tools, free for every tier. The tool estimates VO2 max from your pace using a standard exercise-science formula — the same type of oxygen-cost equation (VO2 ≈ 0.2 × speed in meters/minute + 3.5) that coaches and exercise physiologists have used for decades to estimate aerobic demand from running pace. You just plug in distance and time; and you’ll get splits and paces that will guide you in training.
From Single Test to Meaningful Trend
One test is a data point. Three tests over a training cycle is a trend. Here's how we actually coach athletes through this in our journals:
Before the test: journal what worked last time, what you want to adjust, what pace you're aiming for, whether you're fresh or tired. (Want help with goals and pacing? Head to the goal studio in the app for guidance!)
After the test: what surprised you, did you hit the pace you wanted, how did your body feel, how was your mental game, what worked, what didn’t work, what can you play with differently next time?
Then retest every 4-8 weeks to see how you improve physically and mentally. When we’re looking for evidence your training is working, we don’t just look to see that you’re getting faster. It’s just a data point. We want to check-in with how your runs are feeling, what your headspace is like, and if you feel more confident using specific tools during training and efforts. Treat time trials as a check-in, not a final exam: some days you'll test better than you feel, some days you'll feel amazing and test average. Both are useful information, neither is a failure.
What Changes VO2 Max (and What Doesn't)
It goes up with consistent aerobic training, threshold/tempo work, and a few months of steady base mileage. It doesn't move much from one workout, one week of training, or running fast once in a while — and it's genuinely limited by genetics and training age, which is exactly why we don't compare your number to anyone else's.
Beyond the Number: Training Pace Adjustments
If your VO2 max trend is improving, your training paces should probably shift too — not because you did anything wrong, but because your fitness legitimately changed. A coach can look at that trend and adjust your easy pace so you're actually recovering on easy days while keeping hard days hard. That's exactly what The Team ($19.99/month, cancel anytime) is built for: a plan that adjusts with your fitness, plus a coach watching the data.
You don't need a coach to use the tool. The VO2 Max Calculator is free for every tier, including Free Community — run your first test this week, retest, and see what changed. That's the only comparison that matters.
— Coach Kelly
