The Test

Before outlining the test, it is worth noting that the Bronco is not my preferred method for assessing aerobic fitness. Because it is a shuttle run, athletes are constantly decelerating, changing direction, and accelerating again, which introduces factors beyond pure aerobic capacity. My preference is a continuous 1.2-kilometer run on an athletics track, as it provides a clearer measure of aerobic running speed.

Over the years, I have also used 2.4-kilometer (1.5-mile) and 3-kilometer time trials in both rugby union and rugby league. The 2.4-kilometer test—better known as Cooper’s Test—has extensive scientific support and, like the 1.2-kilometer trial, begins and ends at the same point on the track.

Despite its limitations, the Bronco Shuttle Run has become the most widely used aerobic test for rugby players in New Zealand. Ideally, it is performed on a rugby field while wearing boots. Originally developed in rugby league, where fields are marked every 10 meters, the test consists of a shuttle pattern beginning on the try line:

• Run to the 20-meter line and return.
• Run to the 40-meter line and return.
• Run to the 60-meter line and return.

This sequence totals 240 meters and constitutes one repetition. Athletes complete five repetitions for a total distance of 1,200 meters.

Rugby Union Field Modification

In rugby union, field markings differ, so I prefer a slightly modified version that is easier to administer. Players run:

• From the try line to the 22-meter line and back.
• To the near 10-meter line and back.
• To the far 10-meter line and back to the try line.

This version adds approximately four meters per repetition, or 20 meters in total, but it offers a significant practical advantage: players turn on clearly marked field lines rather than cones, making the test simpler, more consistent, and easier to manage.

Calculating MAS

The term maximal aerobic speed, or MAS, is arguably a misnomer in this context. What we are actually calculating from a Bronco result is an athlete’s average aerobic running speed. However, because MAS is the accepted terminology, I will continue to use it throughout this article.

The resulting MAS value provides the foundation for prescribing conditioning intensities and structuring metabolic conditioning sessions specific to the demands of team sports.

Training Calculations

Before outlining how I develop training plans based on the MAS generated from the Bronco time, I want to reiterate that I do not condition any player simply to run a better Bronco time. The goal is to make them better rugby players.

That said, the Bronco is an excellent rugby-code conditioning drill because of the multiple changes of direction and the ability to individualize timing using percentages of the generated MAS.

To individualize the training drills, we first calculate the percentage increase in the baseline average velocity generated from the test result. In the example above, a 5:17 Bronco converts to an average velocity of 3.79 m/s. From there, we determine the specific velocities for 110%, 125%, and 140% of that result.

Broken Bronco Charts

These velocities can now be used to determine times for the most frequently used conditioning runs based on the Bronco. These are called Broken Broncos: singles, doubles, and triples.

• Single: 1 repetition = 240 meters
• Double: 2 repetitions = 480 meters
• Triple: 3 repetitions = 720 meters

Add the Turn Penalty

Since these are shuttle runs, it is important to factor a turn penalty into each run. The general standard is 1-2 seconds per turn, depending on the athlete’s ability to decelerate effectively and re-accelerate after the turn. For this example, we split the difference and use 1.5 seconds per turn.

The work-to-rest ratio is usually 1:1 or 1:1.5, depending on the player's fitness. My preference is to base recovery on the time taken to complete each interval, allowing the intensity of effort to determine the recovery time so the quality of performance can be maintained throughout the session.

Practical Application

A coach could prescribe sessions such as:

• 6 × Singles @ 140% MAS with 1:1.5 recovery
• 4 × Doubles @ 125% MAS with 1:1 recovery
• 3 × Triples @ 110% MAS with 1:0.5 recovery
• A ladder popularized by Beauden Barrett: 1 to 3, repeat the 3, then back down to 1.

This allows conditioning intensity to be individualized for each player’s Bronco-derived MAS while maintaining the change-of-direction demands relevant to rugby.

Running Program: Two Sessions per Week

Use different sessions each time. For the 5:17 Bronco example, use these Broken Bronco targets:

Workout Options: Choose One from Each Group

Example Week Plan

With a Bronco time of 5:17, you are in a solid fitness range, so balancing speed, MAS, and rugby-specific conditioning is important.

Progression: 4-6 Weeks

For an athlete currently running 5:17, consistently completing these sessions alongside rugby training and strength work could reasonably improve the Bronco by 10-25 seconds over 6-8 weeks, depending on training age, recovery, and body composition.

Elitefts Product Suggestions for Team Sport Conditioning

These product links are included as coach-friendly add-ons for building acceleration, repeat-effort capacity, sled work, and general physical preparedness around the conditioning work above.

Product availability, pricing, and shipping details can change.