True VO2max testing isn’t a simple process. To get an accurate measurement of cardiovascular fitness determined by the volume of oxygen you consume while exercising at maximum effort, you need a treadmill, a metabolic cart, and various tubes and doo-dads designed to collect your inspired and expired air, analyzing it for oxygen consumption and carbon dioxide production — plus, a technician to run everything. It’s kind of brutal.
So when I told an exercise science faculty member at the University of Mary Hardin-Baylor that I was using their lab to test whether a pair of headphones could do the job instead, I was met with not unfounded skepticism.
The more fit you are, the higher your VO2max is, making it a handy number for athletes to track when working to improve their cardiovascular endurance. The trouble, of course, is that true VO2max testing isn’t readily available to most people — to say nothing of it being super uncomfortable.
And that’s where VO2max estimates come in handy. According to a 2004 study published in the European Journal of Applied Physiology, it’s possible to estimate VO2max based on heart rate measurements. And that’s exactly what the Jabra Elite Sport earbuds claim to do (along with monitor your heart rate and track your running distance, pace, cadence, and estimated calorie burn).
The Earbud VO2max Test
Because true VO2max tests are usually performed on a treadmill or an ergometer, I decided to test the earbuds’ feature on a treadmill at the gym. This didn’t work. Several times.
The VO2 testing feature requires 15 minutes of sustained running at a steady(ish) pace on a level(ish) surface. I thought using a treadmill would be a good option. What I didn’t realize was that the in-ear heart rate monitor works in tandem with GPS-tracking to analyze your speed and distance in addition to your heart rate to calculate your VO2max estimate. Unfortunately, GPS can’t really track your distance if you’re running in place.
After three failed attempts and several emails with the company, it was confirmed: The treadmill is a no-go.
So I went outside. The earbuds told me when I’d reached my target heart rate zone, and I maintained that pace until the earbuds told me the test was complete.
The results? My VO2max was estimated at 39 milliliters of oxygen per kilogram body mass per minute, or 39 ml/kg/min. Not bad for a 35-year-old female; VO2max norms tend to be lower for women than men, and tend to decrease with age. But I was a little disappointed. I thought I’d do better, and was hoping for a score in the 40s, which would land me in the “superior” range for my age.
There was still hope though. When I’d spoken with Adam Robertson, Jabra’s Sr. Manager of Product Marketing, he’d told me the results should be accurate within about 5 percent of my true VO2max, which meant when I headed to the university’s exercise science lab for my official test, I should expect a score somewhere between 37 and 41.
The Lab-Based VO2max Test
The day after I completed the earbud test, I headed to UMHB to undergo the Bruce Treadmill Protocol — a more-traditional VO2max test. The lab techs gave me a giant mouthpiece attached to a tube and plugged my nose with a clip so all my inspired and expired air would pass through my mouth and into the tube. I started walking on the treadmill at a 10-percent grade and at 1.7 miles per hour. Not too tough. The trick? Every three minutes, the speed and the treadmill grade increased. A minute into stage five, with the treadmill going five miles per hour at an 18-percent grade, I was finished.
Turns out, my true VO2max is 43.1 ml/kg/minute.
Double-Checking the Earbuds
Given that my true VO2max score fell outside of the predicted 5 percent margin of the earbud score, I figured user-error might have played a role. I performed the earbud test two more times, and scored worse — a 37 and a 38.
Essentially, the earbuds weren’t able to assess my VO2max at the accuracy level they claimed. That said, I appreciate that the headphones underestimated my score rather than overestimated it.
Going forward, I’ll keep using these fancy earbuds for all their fancy features, and I’ll even keep using the VO2max test. But I’ll use it with a grain of salt — not so much to estimate my VO2max, but as a simple way to keep an eye on any possible changes to my cardiovascular fitness.