Free tool
MAS calculator for rugby conditioning
Run 2,000 m as fast as you can, enter your time, and get your maximal aerobic speed plus the exact distance for every interval in a rugby pre-season.
How it works: MAS = distance ÷ time. A 2,000 m run in 8 minutes (480 seconds) is 4.17 m/s. A 15-second rep at 120% of that is 4.17 × 1.2 × 15 = 75 m.
Distances are rounded to the nearest metre. Runs in your browser; nothing you enter is stored or sent anywhere.
How to run the time trial
- Use a running track (5 laps = 2,000 m) or a flat, measured route. Not grass with turns: that’s a different test.
- Warm up for 10–15 minutes with easy running and a few build-ups.
- Run the distance as fast as you can at an even pace. Starting too fast is the commonest mistake.
- Record the surface, weather and shoes, and retest the same way.
In the research behind this calculator, Australian footballers ran time trials from 1,200 m to 2,200 m. Average speed over 1,600–2,200 m matched their lab-tested MAS, 2,000 m agreed best, and 1,200–1,400 m trials read faster than true MAS Bellenger et al. 2015. That’s why this calculator uses 1,600–2,000 m as they are and cuts 1,300–1,400 m results by about 5%, as set in the Match Ready Coaching Rules (F1). It doesn’t accept shorter runs.
The formulas
| What | Formula | Example (2,000 m in 8:00) |
|---|---|---|
| MAS | distance ÷ time in seconds | 2,000 ÷ 480 = 4.17 m/s |
| MAS (1,300–1,400 m trial) | (distance ÷ time) × 0.95 | 1,400 m in 5:00: 4.67 × 0.95 = 4.43 m/s |
| Interval distance | MAS × % ÷ 100 × seconds | 15 s at 120%: 4.17 × 1.2 × 15 = 75 m |
| km/h | MAS × 3.6 | 15.0 km/h |
| Pace per km | 1,000 ÷ MAS | 240 s = 4:00 per km |
World Rugby’s conditioning course uses the same arithmetic: a 15-second grid side at 100% for a player with 3.9 m/s is 58.5 m, and a Eurofit rep at 120% for a 4.0 m/s player is 72 m World Rugby: conditioning using MAS. The calculator reproduces both (it shows 59 m because it rounds to whole metres).
Which session when
Most hard conditioning should sit above about 92% of MAS, because time spent near maximal aerobic speed is what drives fitness gains; running below about 70% counts as recovery Buchheit & Laursen 2013. A typical pre-season order, each method for 2–3 weeks:
- Long intervals (3 min at 93%, then 90 s and 60 s at 100%) to build the base.
- Grids: 15 s at 100% on the long side, 15 s at 70% on the short side, round a rectangle, in 5-minute sets building to 6–8.
- Eurofit 15:15 at 120%, standing still in the rests, rising to 130% after 3–4 weeks.
- 20:10 at 120%, the hardest, only after a block of grids and 15:15s.
- Game-based conditioning, which for amateurs is mostly club training.
On the fast reps, start each one from a standstill so you can’t bank time. Keep hard running and heavy or explosive leg sessions at least 6 hours apart, ideally on different days Schumann et al. 2022. The full plan is in the pre-season training plan, and the test itself is compared with the Bronco and Yo-Yo in rugby conditioning tests.
No time trial? Use heart rate
If you can’t run a time trial (or you’re on a bike or rower), 4 × 4 minutes at 90–95% of your maximum heart rate with 3 minutes easy between is a well-tested alternative Helgerud et al. 2007. On a bike, rower or ski erg, a 5-minute all-out effort gives a machine-specific MAS; repeat intervals on machines cap around 110% rather than 120%.
General training information for healthy adults, not medical advice. A maximal time trial is hard: if you have a heart condition, chest pain, dizziness or are returning from illness or injury, speak to your GP first. Stop if you feel unwell.
Frequently asked questions
What is maximal aerobic speed (MAS)?
Roughly the slowest running speed at which you reach your maximal oxygen uptake. It’s a practical way to set running targets: every interval becomes a distance worked out from your own speed.
How do I test my MAS?
Run a 1,600–2,000 m time trial as fast as you can on a track or measured, flat route, then divide the distance by your time in seconds. 2,000 m matched lab-measured MAS best in the research; 1,200–1,400 m trials overestimated it Bellenger et al. 2015.
What is a good MAS for a rugby player?
There are no validated norms for amateur rugby players, and results depend on the surface and conditions, so we don’t publish a “good” number. Compare your MAS with your own previous tests, run the same way.
What is 15:15 at 120% of MAS?
Fifteen seconds running at 120% of your MAS, then fifteen seconds standing still, repeated. With a MAS of 4.0 m/s, each 15-second rep is 72 m. It’s the Eurofit method in World Rugby’s conditioning course World Rugby: conditioning using MAS.
Can I use a Bronco or bleep test result instead?
Not in this calculator. Those tests correlate with aerobic fitness but involve turns and pacing, and there is no checked formula to convert them to MAS. A straight-line time trial is the simplest valid option.
How often should I retest?
At the start of pre-season and at each change of training phase, roughly every 3–4 weeks in pre-season. Between tests you can move up a grid (about 5%) instead of retesting.
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