In this episode of the Athletes Compass, hosts Paul Warloski and Dr. Paul Laursen, along with guest Marjaana Rakai, discuss the significance of testing for endurance athletes. They cover various tests for cycling, running, and swimming, such as the Functional Threshold Power (FTP) test, critical power test, and MAF (Maximal Aerobic Function) test. The discussion highlights the importance of testing in understanding an athlete's fitness level, setting training benchmarks, and tracking progress.