Why Does Consistency Beat Exactness for Body Composition?

On the show, reliability beats validity for real-world fitness testing. A tool can fall short of being extremely precise and still hold value when it is reliable. The use of that tool is as a metric of whether fitness got better.

The aim is the tool that is both the most precise and the most reliable. When that tool is unavailable, the path is a reliable tool and measurement for consistency. Body composition has inherent error, and the size of the error is not the same for every measure: some errors are smaller and some errors are larger. Standardization within the testing protocol allows progress to be measured and shows where fitness stands.