Field test of intermittent high-intensity running capacity with brief recoveries.
The Yo-Yo Intermittent Recovery Test (commonly Level 1/IR1) requires shuttle runs of progressively increasing speed interspersed with short active-recovery periods until volitional exhaustion, used as a field-based proxy for intermittent aerobic/anaerobic fitness relevant to team sports. It correlates with, but is not interchangeable with, laboratory-measured aerobic capacity.
This guide was auto-drafted and is pending editorial review.