Yo-Yo Intermittent recovery test (YYIRT)

The Yo-Yo intermittent recovery test (YYIRT), created by Jens Bangsbo in Denmark, is a widely used field test and considered one of the most reliable indirect tests available for measuring maximal oxygen uptake (VO2max). This test measures the subject’s capacity to recover from intermittent and progressive high intensity efforts.The YYIRT has been approved to test soccer players and has been related to the reduction of risks of injury.

This test has 2 levels of difficulty:

• • YYIRT-1: Designed for younger subjects or amateurs who have a lower cardiorespiratory capacity (Starts at a speed of 10 km/h (6.2 mph))
  • YYIRT-2: Designed for elite athletes (Starts at 13 km/h (8 mph))

• Required Material: A flat non-slip surface, 6 cones to mark the circuit course, a measuring tape and a stopwatch. Besides, an audio equipment to play back the audio of the test protocol is needed. If the subjects’ heart rate (HR) must be measured, a heart rate monitor will be needed.

• Procedure: The subject shall run in 20-meter back and forth shuttles, between the start (A), turn (B) and finish (A) lines, until reaching exhaustion, at progressively increasing speed controlled by audio signals (beeps) emitted from an audio equipment. Between each back and forth shuttle (A-B-A), 40 meters in total, the subjects have an active recovery lapse of 10 seconds, also controlled by acoustic signals, during which they must perform a recovery jog on a 10-meter distance (A-C-A). The running speed increases progressively, but the recovery time remains constant throughout the test. The first time the subject does not reach the finish line (A) on time, he/she will receive a warning, and at the second warning the test will be terminated and the number of the last shuttle completed will be registered.

• Assessment: The number of back and forth shuttles that the subject is able to cover in a single attempt is measured.

• Remarks: The YYIR-1 test is indicative of the subject’s ability to perform repeated high-intensity aerobic efforts, whereas YYIR-2 determines the ability to perform intense intermittent efforts that require a large anaerobic contribution combined with a significant aerobic component (Krustrup et al. 2006).