Put your fitness in perspective.
Explore your fitness age and VO2 max trends, beyond a single score.
See fitness age as an estimate that adds context to your cardiovascular fitness. Follow the trend alongside your test history. It is not a diagnosis, a biological clock, or a promise of additional years of life.
Try it in VO2 Maximizer ↗Actual app imagery. Check the App Store for current availability.

Understand more.
Get more from every session.
1.5 Mile Run Training: 12-Week Plan to Cut Your Time
The 12-week 1.5 mile run training plan that cut my time by 47 seconds: mile-pace intervals, threshold tempos, base hours, and race-day pacing.
Read the guide ↗Balke Test Training: 12-Week Plan to Run Farther
The 12-week Balke test training plan that lifted my 15-min distance by 330m: threshold work, VO2 max intervals, base hours, and pacing strategy.
Read the guide ↗What Your VO2 Max Score Actually Means
Got a VO2 max number from a lab, field test, or watch? Here is what your score translates to on the FRIEND chart, and what to actually do with it.
Read the guide ↗