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In a lab, scientists often assess athlete’s fitness through a VO2-max test. In a typical test, the subject runs on a treadmill, incrementally increasing speeds until she has to stop. This format is known as an open-loop test because there is no predetermined endpoint. Unlike a race, which has a fixed finish line, this test keeps going until the subject feels she cannot continue. Open-loop fitness tests can be done away from the exercise science laboratory, and although quite challenging, they are a great way to track progress.
During the test, be sure to note the point you reach your max—for example, after 1 minute and 12 seconds of running at 8.8 mph. Wait a few weeks and then repeat the test. If you are able to reach a higher speed or last longer at the same speed, you’re getting fitter.
Open-Loop Performance Test
Challenge Level: High
1. Start with a 5- to 10-minute warm-up at a perceived effort level of 3 on a 1–10 scale.
2. Increase speed by 0.5 mph.
3. After 2 minutes, increase speed by another 0.5 mph.
4. Continue in this manner until your perceived effort level rises to 10.
5. At that point, you can jump your feet on the sides of the treadmill if you need to. Slow down to an easy jog or a walking pace. Cool down for 5 minutes at this low intensity.