Bronco test vs Yo-Yo test: what is the difference?

How they differ

The Bronco is a time trial. Five sets of 20, 40 and 60 m out-and-backs run without a break, 1,200 m and 30 turns in total. The only result is the clock. It lasts 4 to 6 minutes for most players.

The Yo-Yo IR1 is a graded test. Players run 2 × 20 m shuttles at a speed set by an audio track, then walk for 10 seconds, and the speed rises through the test. The result is the distance covered before the player fails twice.

	Bronco	Yo-Yo IR1
Format	fixed distance, timed	graded, stopped at failure
Shuttle	20, 40 and 60 m out-and-backs	2 × 20 m, then 10 s recovery
Recovery	none	10 s after every shuttle pair
Audio track	none	required
Distance	1,200 m for everyone	1,400 m takes about 11 min 40 s, 2,040 m about 16 min 40 s
Turns	30	one every 20 m
Result	total time	distance in metres

The Yo-Yo distances and durations come from the 20 m table behind the Yo-Yo IR1 page, which counts the recoveries.

What the studies found

Two studies put the tests side by side.

Professional players. Sella and colleagues (2021) tested 133 rugby union professionals on both tests. The correlations were very large, r = −0.74 and 0.71. The signs differ because a faster Bronco is a shorter time. The authors still conclude that the scores are not interchangeable.

Amateur referees. Sant’Anna and colleagues (2023) tested 67 amateur referees on both tests and measured their match demands with GNSS trackers. The two scores correlated at r = −0.88, a stronger link than in the players. Yo-Yo IR1 distance correlated with five match measures: total distance, high-intensity distance, maximal speed, high-intensity accelerations and sprints. The Bronco was significantly linked to two: maximal speed and high-intensity accelerations. The authors suggest the Yo-Yo IR1 may be the more valuable test for assessing a referee’s match fitness.

Referees are not players. The result does not say the Yo-Yo IR1 predicts a forward’s match. It says that in this sample, the longer test carried more information about match demands.

What each test is good for

The Bronco is quick and looks like the game. It needs four cones and a stopwatch. One player is done in under six minutes, so a whole squad can be tested in a single session. See the Bronco page for the course and for published Super Rugby times.

The Yo-Yo IR1 tests recovery. The 10 seconds of walking after each shuttle pair are what separates players with the same top speed. The test needs a recording, a third line for the recovery area and room for a walking zone, and it takes longer for fitter players.

Which to run in pre-season

1. Short on time, or testing often? The Bronco.
2. Want to see how a player recovers between efforts? The Yo-Yo IR1.
3. Need a pace for conditioning? Neither: run a beep test to get a MAS. The Bronco vs beep test page explains why.
4. Already have a season of data on one of them? Keep it. A change of test breaks every comparison with the earlier results.

Whichever you choose, keep the surface, the time of day and the warm-up the same. A short warm-up can cost a Bronco runner several seconds, and a slippery surface changes both tests.

Reading the two together

If a player is fast on the Bronco but low on the Yo-Yo IR1, they are probably quick and able to turn but lose fitness when efforts repeat. The reverse points to a player who sustains work but is slower over short, sharp distances. Both profiles tell you what to train. Neither one tells you to drop the other test.