Yo-Yo de resistencia intermitente (YYIET)

The Yo-Yo Intermittent Endurance Test (YYIET), 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 (VO₂ max). It measures the subject’s ability to repeat intermittent and progressive high intensity efforts. The YYIET 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:

• • YYIET-1: Designed for younger subjects or amateurs who have a lower cardiorespiratory capacity (Starts at a speed of 8 km/h (5 mph))
  • YYIET-2: Designed for elite athletes (Starts at 11.5 km/h (7 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 5 seconds, also controlled by acoustic signals, during which they must perform a recovery jog on a 5-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 YYIET test has proven its effectiveness especially in the field of sports, particularly in team sports, due to its specificity.