2 October 2026

How to Calculate MAS (Maximal Aerobic Speed)

To calculate MAS, divide the distance of a maximal continuous run by the time it took, in seconds. A player who covers 1,200m in 5:00 (300 seconds) has a MAS of 1,200 ÷ 300 = 4.0 m/s, or 14.4 km/h. That’s the whole calculation. The rest of the work is choosing a test that puts the effort in the right window, and knowing what to do with the number once you have it.

MAS — maximal aerobic speed — is the slowest running speed at which a player reaches their maximum oxygen uptake. In plain terms it’s the top of the aerobic engine, expressed as a speed rather than a lab value. That one change of units is why coaches bother with it: a speed can be turned into cones on a pitch, and a VO2max score can’t.

If you only want the number, our free MAS calculator does the arithmetic and the training speeds for you. If you want to understand what you’re calculating, and where the estimate can mislead you, read on.

Key takeaways

• MAS (m/s) = distance in metres ÷ time in seconds, for one maximal continuous effort.
• The effort needs to last roughly four to six minutes. Shorter and you’re measuring anaerobic capacity; longer and the player paces themselves below MAS.
• A Bronco-derived MAS reads slightly low because the turns cost time. Treat it as a conservative floor.
• MAS is only useful once you convert it into training speeds: 15 seconds on, 15 seconds off, at 100–120% of MAS.
• There is no validated general underage MAS table. Compare a young player with their own last result, not with an invented norm.

The MAS formula

MAS (m/s) = distance in metres ÷ time in seconds

Written out: convert the time to seconds, divide the distance by it, and you have metres per second. Multiply by 3.6 if you want km/h, which is the unit most players find easier to picture.

Three worked examples, using the Bronco test (1,200m):

The same arithmetic works for any distance. A 1.5km time trial in 6:00 is 1,500 ÷ 360 = 4.17 m/s (15.0 km/h). A six-minute run covering 1,450m is 1,450 ÷ 360 = 4.03 m/s.

Notice how little separates a 4:45 Bronco from a 5:15 one in MAS terms: 4.21 against 3.81 m/s, about a 10% gap. That matters, because it means small timing errors move the number. Half a second of stopwatch lag on a 300-second run is a 0.3% error and harmless. Starting the watch late by three seconds is 1%, and across a season of retests that kind of sloppiness is the difference between a real trend and noise.

Which field test to use

Any maximal continuous effort of roughly four to six minutes approximates MAS. That window is the only real constraint, and it’s the one clubs get wrong most often.

Below about four minutes, a player’s anaerobic contribution inflates the result — you’re measuring a different quality and calling it MAS. Above about six minutes, players instinctively pace themselves, settle below their true maximal aerobic speed, and the estimate drifts low. So the right test is the one that keeps your players inside that window, which depends on how fit they actually are.

The 1.5km time trial

The classic field version, and the cleanest: a continuous run on a track or a measured loop, no turns, flat out.

MAS = 1,500 ÷ time in seconds.

It suits reasonably fit adult squads, where 1.5km lands between about 5:00 and 6:30. Watch the window, though: a player taking 7:30 is running for too long for the result to be a fair MAS estimate, and in a mixed club panel you will have those players. The fix isn’t to make them run harder, it’s to use a shorter test for the whole squad so everyone is measured the same way.

The Bronco test

Five continuous rounds of 20m + 40m + 60m shuttles, 1,200m in total. It’s become the default endurance test in GAA for a simple reason: it needs cones and a stopwatch and nothing else.

MAS = 1,200 ÷ time in seconds.

One honest caveat, and it’s the most important sentence on this page: the Bronco involves a turn every 20 to 60 metres, and every turn costs time a straight run wouldn’t. So 1,200 divided by a Bronco time slightly understates true MAS. That’s not a reason to avoid it — it’s a reason to treat the output as a conservative floor. Training speeds built from a Bronco-derived MAS come out achievable rather than optimistic, which for a club squad is the right side to miss on. What you must not do is compare a Bronco-derived MAS with a time-trial-derived one and call it progress. Same test, every time.

If you want to know whether the Bronco time itself is any good before converting it, our Bronco test calculator rates it against published adult amateur bands.

The six-minute run

Run for six minutes, measure the distance covered, divide by 360. Useful when your squad’s fitness varies enormously, because it’s time-capped: everyone finishes together, and nobody is still out on the pitch at 8:00 wondering why. The cost is that you need a measured track or a marked grid to read distance off accurately.

What doesn’t convert

The Yo-Yo Intermittent Recovery Test has built-in recovery walks, so its result isn’t a continuous running speed and doesn’t convert to MAS with this formula. Keep it as its own benchmark.

The 30-15 Intermittent Fitness Test produces its own reference speed, VIFT, which is deliberately not MAS — it’s typically higher, because it bakes in the cost of changing direction and the player’s anaerobic contribution. VIFT is a perfectly good number to build training from, but prescribe off VIFT percentages, not MAS percentages. Swapping them silently is a real way to make a session much harder than intended.

How to run a MAS test with a club squad

The calculation is trivial. The protocol is what makes the number trustworthy twelve weeks later.

1. Pick one test and write it down. Bronco, 1.5km or six-minute run. Record which one. In two years, nobody will remember.
2. Warm up properly. A cold maximal aerobic effort is both a worse result and an injury risk. Ten minutes of progressive running and mobility.
3. Run it last. Endurance testing wrecks a player for everything else. Sprint, jump and strength tests come first — the ordering logic is covered in the complete guide to GAA fitness testing.
4. One recorder, one job. A dedicated timekeeper per group with a written sheet. Mis-recorded data is worse than no data, because you’ll trust it.
5. Note the conditions. Wind, surface, temperature, grass or astro. A 2% difference between retests is often weather, not training, and the note is what lets you tell.
6. Brief the pacing. Players who sprint the first round of a Bronco and die in round four post a worse time than their fitness deserves. Tell them it’s a maximal even effort, not a sprint.
7. Book the retest before you leave the pitch. One MAS value is a snapshot. The habit of retesting is the whole point, and it’s the step most clubs skip.

If this is your first time organising a session like this, how to run your first club testing day walks through the full evening, stations and all.

What’s a good MAS?

Adult male club players in Gaelic games typically land somewhere around 4.0–4.7 m/s (roughly 14.5–17 km/h), with intercounty players higher again. Treat that as a rule of thumb, not a standard: the test used, the surface, the sex of the player and their age all move the numbers, and published figures vary widely depending on whose squad was measured.

For underage players, be careful. There is no validated general youth MAS table worth printing, and plenty of the “norms” circulating online are built on small or irrelevant samples. Scoring a 14-year-old against a fabricated age band tells you nothing and risks writing off a late developer who simply hasn’t grown yet.

The honest comparison for any player, and especially a young one, is their own previous result. Same test, same conditions, twelve weeks apart. A player who moves from 3.8 to 4.0 m/s has gained about 5% of aerobic engine, and that’s a real, defensible finding regardless of what any norm table says.

Turning MAS into training speeds

This is why you calculated it. On its own, “4.0 m/s” is trivia. Converted into percentages, it becomes a prescription that’s individual to each player.

The standard MAS session is intermittent running: 15 seconds on, 15 seconds off, at 100–120% of MAS, in blocks of six to ten minutes. The practical trick is to convert the target speed into a distance the player covers in the work interval, mark it with two cones, and have them run cone to cone.

For a player with a MAS of 4.0 m/s:

The real value shows up with a full panel. Give every player the same cone distance and you’re training some of them at 85% and others at 125% of their own maximum — the fit ones coast, the weaker ones blow up, and the session does neither group much good. Give each player their own cones and one session trains the whole squad appropriately. That’s the entire argument for bothering with MAS.

Our MAS calculator prints this table for any time you enter, including the 15-second distances, so you can set a session up from a testing sheet in a couple of minutes.

Four common mistakes

• Mixing tests between retests. A Bronco-derived MAS and a time-trial-derived MAS are not comparable. Switching tests and reading the difference as progress is the single most common error.
• Letting players pace. Submaximal efforts produce submaximal MAS. If the squad finishes looking comfortable, you measured their pacing discipline, not their engine.
• Prescribing off a squad average. The average MAS of a panel is a number no individual player has. Use each player’s own value.
• Calculating it once. A single MAS value sets cones for one block. The trend across three testing days is what tells you whether the conditioning programme actually works.

Frequently asked questions

What is the formula for MAS?

MAS in metres per second equals the distance of a maximal continuous run in metres divided by the time in seconds. A 1,200m Bronco in 300 seconds gives 4.0 m/s. Multiply by 3.6 to convert to km/h.

Can I calculate MAS from a Bronco test?

Yes — divide 1,200 by the Bronco time in seconds. Because the Bronco includes a turn every 20 to 60 metres, the result reads slightly below true MAS, so treat it as a conservative estimate rather than a lab value. Use the same test at every retest so the comparison holds.

What is a good MAS for a GAA player?

Adult male club players commonly sit around 4.0–4.7 m/s (14.5–17 km/h), with intercounty players faster again. Age, sex and the test used all shift the figures, so treat published ranges as guides. For underage players, compare against their own previous result rather than an age norm, because no validated general youth MAS table exists.

How often should I retest MAS?

Every 10 to 12 weeks, in step with the rest of your testing battery — typically the start and end of pre-season, optionally mid-season, and end of season. The change between two results is more informative than any single value.

Is MAS the same as VO2max?

No, though they’re closely related. VO2max is the volume of oxygen a player can use, measured in ml/kg/min. MAS is the slowest running speed at which that maximum is reached. MAS is the more useful of the two for a coach because it’s already in units you can mark out with cones.

Start with one test, done properly

Calculating MAS takes a stopwatch and a division. Making it useful takes slightly more: one test chosen and recorded, the effort kept inside the four-to-six-minute window, conditions noted, and a retest in the calendar before anyone leaves the pitch.

Do that, and three months later you’ll have something most clubs never get — two comparable numbers per player and a defensible answer to whether the conditioning block worked.

FitScorePro scores a full squad’s testing against age- and sex-banded norms automatically and keeps the history in a record the club owns, so the trend survives every coaching change. Book a 20-minute demo if that’s the part you’d rather not do by hand.