By text, spoken word, photos and animations you are guided easily through the way of performing each of the Yo-Yo tests and how to evaluate the test results. The Yo-Yo tests contain running activities that are relevant for many sports. The tests can be performed by both men and women of all ages. The tests can also be used for assessing the physical capacity of young athletes. However, frequent testing of children less than 14 years of age ought to be avoided, as this age group should only perform systematic fitness training to a minor extent. The basics of the tests are simple: For the Yo-Yo endurance test, two markers are positioned at a distance of 20 meters. The CD is placed in a CD player and the test can be performed. The individual begins to run forward 20 meters at the time of a signal given on the CD. The running speed should be adjusted, so that he or she reaches the 20 meters marker exactly at the time of the next signal. A turn is made at the 20 meters marker and the individual runs back to the first marker, which has to be reached at the time of the next signal. If an individual runs the distance too quickly he or she must wait at the marker until the next signal. The principles of the Yo-Yo intermittent endurance test and the Yo-Yo intermittent recovery test are similar to the Yo-Yo endurance test, except in the intermittent tests the participants have a short active break (5 and 10 seconds for the endurance and recovery test, respectively).