How Fit Are You? Here’s How a Star Athlete Can Tell

Professional athletes get accustomed to undergoing a battery of physical tests to help maximize performance. There’s everything from routine blood draws to lactate testing—but the most dreaded test of all? The VO2 Max.  

First, what the heck is V02 Max? It’s a measure of how much oxygen your body can use while you exercise at maximum effort. It’s a useful number to know, too, as it correlates to your fitness level and potential for endurance-based activities. I remember getting results when I was at different fitness levels, and my VO2 Max numbers varied from 74 to 81 depending on how fit I was. It’s nice to know that when the number is going up, you are getting fitter.

I only measured my VO2 Max three times during my professional running career, though, because the process is so painful. First of all, with the test, you have to run to complete exhaustion—essentially, until failure. Now, I know what you are thinking: It sounds like a race. The difference is that in a race, you know you will run your hardest, but you hope that your efforts will be rewarded with a fast finish. But with a V02 Max test, you are guaranteed to fail.

Traditional VO2 Max testing is done in a lab on a treadmill, and you need to wear an air-tube mask to collect the volume of air you breath in and then exhale. A technician adjusts the treadmill during the test, so that it keeps getting faster and faster, or steeper and steeper, (or maybe both depending on your lab technician’s mood), to push your intensity to the max. Imagine running in place with a giant mask bouncing on your head with every step, saliva flying everywhere. Meanwhile, you’re running as hard as you can, all the while knowing you are going to fail. The VO2 Max test is definitely not my idea of a good time. However the results are incredibly useful, so almost all professional athletes endure a V02 Max test at some point in their career.  

What’s incredible, though, is now you can enjoy similar results using a Fitbit Charge 2 tracker to get your Cardio Fitness Score—which is based on your estimated VO2 Max—without having to set foot in a lab. I only wish that in my competitive running days, I had the technology that Fitbit has established to give me a snapshot of my fitness level, without having to go through the expense and rigors of testing. It’s even better, too, because now I can view my Cardio Fitness Score and see it changing over time whenever I choose to look. I can more effectively use the information rather than just know my VO2 Max score once in a long while, and without any real-world implications.

You might be wondering, since you may not be a professional athlete, what the real world application of knowing your VO2 Max or Cardio Fitness Score might be. It’s pretty simple, really: Seeing your score improve over time shows you that you are training effectively. All the time you’re putting into your workouts is paying off!

Obviously there are more ways to gauge your fitness level than just by knowing your VO2 Max, such as workout improvements (if you can run farther or lift more weights), or race times. But sometimes it’s hard to truly know, because the conditions may not be the same. For example, you might show up for your 5K road race and it’s 95 degrees Fahrenheit outside, humid, and the course is hilly, so you can’t compare your time to when you last raced a 5K in cool climes on a flat course. This is where knowing your score comes in handy: You can more clearly understand if you are improving or not, and seeing your score change over time is one of the most accurate ways to measure your change in fitness. It’s not just for the pros anymore, and it’s pretty motivating, too.

Ryan Hall

Ryan Hall is a former professional distance runner. He is one of America’s premier distance runners, and represented the United States in the 2008 and 2012 Olympic Games. He ran one of the fastest marathons ever, finishing 4th at the 2011 Boston Marathon, and holds the American Record for the half-marathon in 59:43.