The Yo-Yo IR2 test: physiological response, reliability, and application to elite soccer

Area of Science:

• Sports Science
• Exercise Physiology
• Human Performance

Background:

• The Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2) is used to assess athletes' ability to perform intense intermittent exercise.
• Understanding its physiological response, reliability, and validity is crucial for its effective application in sports science.

Purpose of the Study:

• To examine the physiological response, reliability, and validity of the Yo-Yo IR2 test.
• To determine the test's effectiveness in evaluating athletes' intermittent exercise capacity.

Main Methods:

• Thirteen normally trained male subjects performed four Yo-Yo IR2 tests, an incremental treadmill test (ITT), and sprint tests.
• Muscle biopsies, blood samples, and heart rate monitoring were conducted during the Yo-Yo IR2 test.
• 119 elite Scandinavian soccer players completed the Yo-Yo IR2 test multiple times.

Main Results:

• Yo-Yo IR2 performance averaged 591 ± 43 m (4.3 ± 2.6 min) with a 9.6% test-retest coefficient of variation.
• Heart rate at exhaustion was 191 ± 3 bpm (98% HRmax), with significant muscle lactate accumulation.
• Performance correlated with ITT and VO2max but not sprint performance; elite players and specific positions showed higher scores.

Conclusions:

• The Yo-Yo IR2 test is reproducible and suitable for evaluating intense intermittent exercise capacity.
• It effectively measures aerobic and anaerobic energy turnover.
• The test is a sensitive tool for differentiating soccer player performance based on competitive level, position, and training status.