Ever wonder how fit you are not just how hard that last run felt or whether you could pedal up a steep hill, but how you'd score on a test that scientifically measures your physical fitness?
I headed to Sports Performance International in Northwest Austin to find out.
Once I checked in and signed a waiver, Ashlee Simpson, who has a master's degree in kinesiology, happily strapped a mask over my face and cracked the whip as I ran like a scalded dog in a test that indirectly determines VO2 max.
Experts say VO2 max is the one of the best measures of aerobic fitness. It represents the volume of oxygen the body can consume while exercising at maximum capacity.
Honestly, though, the test stinks. After being fitted with headgear that covers your mouth and nose, you run on a treadmill that gets incrementally faster and steeper. The machine analyzes how much you exhale and then uses an algorithm to estimate your VO2 max.
Unfortunately, you feel like a hamster on a spinning wheel. Or a woman with a bag over her head running up a hill.
I warmed up with a slow jog. Every 30 seconds or so Simpson upped the speed of the rubber path to nowhere until it reached 7 mph, or a pace of about 8:34 per mile. Then she gradually amped up the incline, until I felt like I was slogging up Mount Everest.
By the end, I thought my heart might explode. When I could go no further, I signaled Simpson, who turned down the speed, let me cool down and handed me a glass of water and a towel.
As it turned out, my VO2 (volume of oxygen) max is really good. The median score for someone my age is 33 ml/kg/min, and I turned in a 48.8. According to a chart from the American College of Sports Medicine, I scored above the 90th percentile for ages 40-49 (I'm 48).
That's up from testing I had done at the Fitness Institute of Texas at the University of Texas in 2004, when my VO2 max score was a 43.8. Then, I was just swimming. Now I bike to work and run, too. Older and stronger!
Numbers vary, of course, but VO2 max normally peaks at about age 20 and decreases by nearly a third by age 65.
Still, compared with elite athletes, who turn in VO2 max values higher than 60, I'm nothing remarkable. Norwegian cross country skier Espen Harald Bjerke, for example, reportedly had a VO2 max of 96. Runner Steve Prefontaine scored 84.4, cyclist Lance Armstrong registered an 84, and marathon runner Joan Benoit had a 78.6.
A high VO2 max score represents an athlete's potential, but it's no guarantee of performance. Think of it as the size of the engine in a car.
It's fun, though, to plug the number into the online calculator at tinyurl.com/bofj5ta, which predicts race performance based on VO2 max. According to the calculator, I should be able to run a 5-kilometer race in a tad over 20 minutes, a 10K in about 42 minutes, a half marathon in about an hour and a half and a marathon in about 3 hours.
Sadly, I don't run that fast. My best 5K ever, in cool, comfortable Michigan last year, was a little over 24 minutes. And my last half marathon was a 2:02:20.
But at least I know my body has the capability to go faster.
At Sports Performance International, Simpson uses the test numbers to help runners recovering from injuries get back into the training groove. The test also helps uninjured folks like me. You get a printout of results that you or your coach can use to plan a training program that's based on science, not guesswork.
One of the numbers you'll get is maximum heart rate, which can be used to help you determine how hard to push when you are training. It's called "heart rate training zones," and they're essentially guidelines to measure your exertion rate.
Zone 1 is the recovery zone, when you should exercise at 70 percent to 85 percent of your maximum heart rate. In Zone 2, the base training zone, you increase it slightly, to 86 percent to 90 percent. That's a good steady rate for a long, easy run.
Zone 3 is the tempo zone, or 91 percent to 96 percent of your max. And Zone 4, race pace, is 97 percent to 99 percent. Zone 5, which is even harder, is where you really push it with interval and speed work.
A running coach (or triathlon group like Tri Zones Training) can work with you once you know your numbers to determine how much time you should spend exercising in each zone. By working in different zones, you improve different aspects of your fitness, from endurance to speed.
And all that information makes that 10 minutes of agony spent taking the fitness test worth it.
Contact Pam LeBlanc at 445-3400. Twitter: @fitcityleblanc