The Yo-Yo Intermittent Recovery test, and why field sports prefer it
Yo-Yo IR1 explained — how the 10-second recovery period changes what is being measured, the reference source behind each age band, and why it maps onto soccer and hockey better than a beep test does.
It will not print percentile numbers. Every reference band behind Vimasu is currently marked sourced, pending audit — cross-checked against the original publication is a step we have not finished, and a number a parent might act on is the wrong place to be approximately right. What follows is the protocol, the named source behind each age band, and what the result does and does not mean. The full methodology and source bibliography sits one level up.
What the test actually measures
Yo-Yo IR1 measures the ability to repeatedly perform high-intensity work with incomplete recovery. The athlete runs 2×20m — out and back — at a dictated pace, then gets 10 seconds of active recovery before the next repetition. The pace increases progressively; the test ends after two failures to make the line in time.
The recovery interval is what separates it from the beep test. A continuous ramp measures how fast you can go before your aerobic system fails. An interval protocol measures how quickly you clear the cost of the last effort so you can produce the next one — which is what a midfielder does roughly every ninety seconds for eighty minutes.
The score is recorded as total distance covered, which makes it a more granular figure than a level-and-shuttle and easier to track meaningfully across a season.
The protocol, and why it decides whether the number means anything
The 10 seconds is not approximate. Active recovery means jogging a marked 2×5m, not standing still, and not being hurried by an impatient timekeeper. Compressing the recovery inflates the difficulty; extending it inflates the score. Either way you have changed the test.
Run IR1, and say so. There is a Level 2 protocol that starts faster and is intended for well-trained adults. Recording "Yo-Yo" without the level is the most common way youth data becomes uncomparable a year later.
Group size changes the result. Athletes run in a pack and pace off each other; a solo tester and a group of twenty produce different numbers from the same person. Keep it consistent between tests.
Familiarisation matters as much as it does in the beep test. First attempt is a rehearsal.
Where the reference comes from
U10, U12, U14, U16, U18 resolve against Bangsbo, Iaia & Krustrup 2008. The source population is 2,200. Bands are held separately for male and female athletes. Full citation: Bangsbo J, Iaia FM, Krustrup P. The Yo-Yo Intermittent Recovery Test. Sports Medicine 2008;38(1):37-51, with Castagna et al. 2010 for youth soccer calibration.
Every band above is currently flagged sourced, pending audit — the source is named and the values are in place, but our cross-check against the original publication is not finished. That is why this page names sources and populations rather than printing percentile numbers. The live coverage matrix, which is fetched from the platform rather than written by hand, is on the methodology page.
What the number does not tell you
It rewards a specific fitness quality, not overall athleticism. A fast, powerful player with poor repeated-effort capacity can score badly and still be the best player on the pitch. The test answers one question well and no others at all.
Youth calibration is thinner than adult calibration. The underlying protocol is well established in adult and academy populations; applying it across U10 to U18 relies on youth-specific calibration layered on top, and the confidence at the youngest end of that range is lower than at the oldest.
It is demanding enough to need care in placement. A maximal repeated-sprint test late in a heavy training week measures accumulated fatigue. Schedule it deliberately, and schedule the retest the same way relative to the week.
Questions parents and coaches ask
- What is the difference between the Yo-Yo test and the beep test?
- The 10-second active recovery between shuttles. The beep test runs continuously to exhaustion and measures aerobic capacity; the Yo-Yo IR1 inserts recovery and measures how well an athlete repeats high-intensity efforts. For sports built on repeated sprints, the Yo-Yo is closer to the actual demand.
- Which Yo-Yo level should youth athletes do?
- Level 1 (IR1). Level 2 starts at a higher speed and is designed for well-trained adult athletes; running it with youth athletes produces a short, uninformative test and an unpleasant experience. Always record which level was used.
- Can Yo-Yo scores be compared between clubs?
- Only if both clubs ran IR1, with a full 10-second active recovery, in comparable group sizes and conditions. In practice those conditions are rarely documented, which is why the comparison worth trusting is an athlete against their own previous result.
Testing is only worth it if the numbers go somewhere.
Vimasu records test results against age-referenced norms and keeps them on the player's permanent record — so a retest in six months is a comparison, not another isolated number. Start free.
Related in the Standard
- glossaryAthleticism (Pillar)
The Athleticism pillar is physical capacity — speed, strength, endurance, coordination, and agility. The body's ceiling on what skill and decision-making can produce. One of the Four Pillars used in youth-sports development.
- glossaryAge Band
The age grouping a player falls into for the season — U8, U10, U12, U14, and so on. Anchored to birth year, age bands keep evaluations comparable across coaches and seasons.
- benchmarkBeep test scores by age: what the number actually measures
The 20m multi-stage fitness test explained — the protocol that makes a level comparable, the reference source behind each age band, and why a beep test score is a poor way to compare two children and a good way to compare one child to themselves.
- rubricSoccer Athleticism Rubric — U12
A coach-grade evaluation rubric for the Athleticism pillar at U12 soccer. Behavioral anchors for acceleration, agility and change of direction, game endurance, and coordination — read against age and maturity, not raw size.
- glossaryFour Pillars (Youth Sports Development)
The Four Pillars are the four domains of youth athlete development — Technical, Tactical, Athleticism, and Mental — used by academies to evaluate, plan, and communicate progress holistically rather than by score alone.