What Your Yo-Yo IR1 and IR2 Score Actually Means
What does your Yo-Yo IR1 or IR2 distance actually tell you about your VO2 max, your sport-specific percentile, and your readiness for team sport?
Is the Yo-Yo IR1/IR2 Test Outdated? The Verdict
The Yo-Yo IR1 and IR2, validated by Krustrup et al. in 2003 and 2006, still hold the intermittent-sport field-test slot: nothing has replaced the recovery-window structure that mirrors match demands.
Is the 1.5-Mile Run Test Outdated? (2026 Update)
The 1.5-mile run is being downgraded, not deleted: the 2026 USAF PFA update brings a 2-mile run and 20-meter HAMR shuttle alongside it, while the original protocol still anchors adult and entry fitness screening.
Is the Balke Test Outdated? The Case For and Against
The Balke 15-minute field test and the 1959 treadmill protocol both still earn their slots: paced VO2 max for adult runners and a cardiology graded test that has outlasted six decades of competing protocols.
Is the Cooper Test Outdated? The Case For and Against
The Cooper 12-minute run still earns its place in adult VO2 max screening: validated since 1968, sustained by Penry and Wilcox in 2010, and unmatched for cost versus accuracy on a 400-meter track.
How to Run a Yo-Yo IR1/IR2 Test (Step-by-Step)
TL;DR. The Yo-Yo intermittent recovery test (IR1 and IR2) is a 20-meter shuttle test with a 10-second active recovery between shuttle pairs. It was designed by Jens Bangsbo at the University of Copenhagen in the mid-1990s to test the specific energy-system demands of football, rugby, hockey, and basketball, which sit between continuous running and pure…
How to Run a 1.5-Mile Test (Step-by-Step Guide)
TL;DR. The 1.5-mile run test is a fixed-distance, time-trial version of the Cooper. You run 2.41 kilometers (one and a half miles) as fast as you can on a flat 400-meter track, and the time-plus-weight regression from George 1993 converts your finishing time to a VO2 max estimate. The US Air Force, US Navy, FBI…
How to Run a Balke Test (Step-by-Step Guide)
TL;DR. The Balke test has two versions and people constantly mix them up. The original 1959 Balke protocol is an incremental treadmill test at fixed speed with a rising grade, designed by Bruno Balke at the US Civil Aeromedical Research Institute for Air Force pilots. The modern field adaptation is a 15-minute maximum-distance run on…
How to Run a Cooper Test (Step-by-Step Guide)
TL;DR. The Cooper test is simple on paper and brutal in practice. You need a flat 400-meter track, a stopwatch, and the willingness to hold a pace that hurts for 12 minutes. Warm up for 12 minutes, run for 12 minutes at the fastest steady pace you can sustain, record the distance to the nearest…
Yo-Yo IR1 and IR2 World Records: Highest Levels Ever
TL;DR. The Yo-Yo IR1 has a theoretical ceiling of level 23.8 (about 3,700 meters), but the highest verified score in published sources is Harry Grant’s 22.8 at the GWS Giants Academy preseason in 2020. Most of the elite tier sits between 22.0 and 22.8 across Australian Football, English football, basketball, cricket, and rugby. The highest…