What does a submaximal cardio test estimate?

• A. Maximum heart rate.
• B. VO2 max without requiring maximum effort.
• C. Lung volume.
• D. Muscle strength.

Answer: (B)

Submaximal cardio tests estimate VO2 max without requiring maximal effort. The idea is that during submaximal, steady-state exercise, heart rate rises in a fairly predictable, roughly linear way as oxygen use increases. By having you work at known, submax intensities and measuring the heart rate, you can extrapolate to the heart rate you would have at maximal effort and translate that into an estimate of maximal oxygen uptake. This approach is safer and more practical than a true maximal test.

Lung volume and muscle strength aren’t what these tests measure. Lung volume is assessed with spirometry, and muscle strength is tested with resistance measures. The test also doesn’t directly measure maximum heart rate; it uses submax heart rate responses to estimate VO2 max.