Testing, Testing...Fitness Testing
/If you want to make sure you’re getting the most out of your training, you’ve got to monitor improvements to fitness. There are a number of ways to do this, the gold-standard of which is through testing in a laboratory. We’ve covered a variety of lab tests in this blog before including lactate threshold testing and VO2max testing. However, there are a variety of other ways to assess fitness that can be easier to perform on a regular basis.
Predicting VO2max
By far the easiest way to assess fitness is by using a fitness prediction equation because no exercise is required and you can use basic metrics. For example:
As you might suspect, though, these simple prediction equations are not all that accurate, especially for athletes. Prediction equations do not account for the well-known genetic influence on VO2max, are often unable to account for changes in training, and have lower accuracy at the extreme ends of the scale (in other words, have low accuracy for those with a high VO2max).
Maximal Field Testing
Considering the low accuracy of prediction equations, a better option is the field test. Within the cycling world, the most common field test is the 20min power test, in which you perform a 20min time trial. Another duration gaining in popularity is the 8min power test involving two 8min efforts. The 8min power test can be great for those living in an area where they cannot ride uninterrupted for 20min or who have difficulty properly pacing themselves for 20min.
For those with a power meter, the key metric of these field tests is average power output, while those without a power meter can measure distance traveled. These metrics don’t tell us VO2max, but increases to power or distance traveled can still indicate improvements to fitness. Of note, the power output from these tests can be used to estimate lactate threshold or “functional threshold power”. Taking 95% of 20min power or 90% of 8min power provides a good estimation of lactate threshold. Estimations from a 20min test will often be different than those from an 8min test, though, so it’s best to stick with one kind of test when monitoring fitness over time.
Submaximal Field Testing
A 20min or 8min field test is great but requires a maximal effort, which is not something most folks look forward to. Another option is the submaximal test. “Submaximal” refers to an intensity that can be maintained for a prolonged period of time (typically <85% of max heart rate), putting this type of test right in between prediction equations and maximal field testing. A submaximal test can take a variety of forms. A submaximal test can predict VO2max by extrapolating heart rate and power data to an estimated maximal effort. Some of the research I’m working on at the moment though, suggests this prediction is not terribly accurate.
Another way to perform a submaximal test is by just comparing the relationship between heart rate and power output. With improvements in fitness, there are changes to the power and heart rate relationship such that at a fixed power, there are decreases in heart rate (or at a fixed heart rate, there are increases in power). Based on this, fitness can be regularly assessed by riding at a clamped power or heart rate and examining changes in heart rate or power, respectively. Of course, heart rate can be influenced by a number of factors (e.g. caffeine, stress, fatigue) so this type of test needs to be performed more than once. Typically, you don’t even need to consciously perform this “test”. Instead, you can monitor the power and heart rate relationship during your regular training and track improvements throughout the year.
The number of ways to assess fitness can be overwhelming. In fact, I teach a class where the entire semester is devoted to learning about fitness assessment methods. However, regularly measuring fitness is important because as the famous mathematician Karl Pearson said, “that which is measured improves” and I know we all want to improve our fitness. Thanks for reading!
