Free tool
MAS calculator
Work out an athlete’s Maximal Aerobic Speed (MAS) from a time trial or the Yo-Yo IR1, and the running speeds to train at. Free, with no sign-up.
Built by Nathan Heaney, The Conditioning Consultant, from 20 years of team-sport conditioning and his own Yo-Yo IR1 research.
MAS calculator
Estimated MAS
– km/h– m/s
Enter a distance and time to see MAS.
| Speed | km/h | m/s |
|---|---|---|
| Estimated MASTrain from this | ||
| Raw final speedNot MAS |
Training speeds from MAS
| %MAS | km/h | m/s | Pace /km | 200 m |
|---|
Method: Bellenger et al. (2015), for time trials of 1.2 to 2.2 km.
Which %MAS for which session? The MAS Blueprint sets it for 10 conditioning types. Testing a whole squad? conditiond works out every athlete’s MAS and builds each group’s sessions.
The basics
What is Maximal Aerobic Speed?
Maximal Aerobic Speed (MAS) is the lowest running speed at which an athlete reaches their maximal oxygen uptake (VO2max). It is measured with a field test, so you need no lab, and it gives every athlete a personal speed to prescribe conditioning from.
That matters because one distance in one time is a different session for every player. When a squad runs the same 72 m in 13 seconds, the fitter players work at around 108% of their MAS and the less fit players at around 125%. Prescribing from each athlete’s own MAS gives everyone the session you meant them to have. Read why one run doesn’t fit all →
Testing
Two ways to test MAS
The calculator takes one self-paced test and one incrementally paced, intermittent test. Both give a sound MAS when they are converted properly.
Self-paced
A time trial
Run a measured distance as fast as possible, on a flat oval or track, pacing it evenly. A whole squad can run it at once.
Choose a distance between 1.2 and 2.2 km so that most of the squad finishes in about 6 to 8 minutes. If most take longer, drop the distance in 200 m steps.
A shorter time trial is run a little faster than MAS and a longer one a little slower, so the calculator adjusts for the distance.
Incremental and intermittent
The Yo-Yo IR1
Athletes run 2 × 20 m shuttles at speeds that rise each level, with 10 seconds of active recovery between shuttles, until they can no longer keep pace. The changes of direction make it feel more like a team-sport game.
In Nathan’s research, the raw final speed overestimated MAS, so the calculator uses the total distance covered instead.
The 30-15 Intermittent Fitness Test is another good option, but its final speed is not MAS either. Which test to choose, how to run it well, and how to convert each one is all in Workshop 1: Fitness Testing & Maximal Aerobic Speed Determination.
The research behind it
Where the Yo-Yo IR1 conversion comes from
Nathan compared the Yo-Yo IR1 with a laboratory VO2max test in state-level netballers. The raw final speed of the Yo-Yo IR1 overestimated the speed at VO2max, while the total distance covered predicted it closely. The calculator uses that relationship.
For example, an athlete who reaches level 18.2 (1,800 m) has a raw final speed of 16.5 km/h, but an estimated MAS of 16.0 km/h. For a 4-minute interval at 90% MAS, the raw speed would have them run about 31 m too far on every repetition.
The study was small, with 10 athletes, so the equation still needs checking in other sports and levels.
Prescription
How to use MAS
Prescribe running as a percentage of MAS. At 90% MAS, an athlete with a MAS of 16 km/h runs at 14.4 km/h and covers 200 m in about 50 seconds. A teammate with a MAS of 14 km/h runs the same session at 12.6 km/h. Same session, same effort, different speeds.
Above MAS, the gap between MAS and maximal sprint speed, the anaerobic speed reserve (ASR), starts to matter. Prescribing from MAS + %ASR gives a more even dose. The Anaerobic Speed Reserve webinar covers how.
Browser tool
MAS Blueprint
The right %MAS for 10 conditioning types at three intensities, and training zones from one MAS.
Excel and Google Sheets
MAS Conditioning Spreadsheet Package
MAS determination, session prescription and ASR for a whole squad, in one workbook.
Free download
MAS Time Trial & Race Calculator
Already have MAS? Turn it into a realistic time-trial target, and race predictions from 2 km to the marathon.
For a whole squad
Run it for every athlete with conditiond
TCC teaches the how and the why. conditiond ↗, the conditioning platform Nathan co-founded, does the working out for a whole squad, every session.
- MAS from nine field-test protocols, including the time trial and the Yo-Yo IR1
- Athletes sorted into conditioning groups by MAS, with manual override
- One session design gives every athlete their own distance, pace and rep time
- Athletes get their own numbers on their own phone
Questions
MAS calculator FAQs
Which is better, a time trial or the Yo-Yo IR1?
Both work. A time trial is simple and quick to run with a whole squad, but depends on even pacing. The Yo-Yo IR1 sets the pace for the athlete and includes changes of direction. Choose one and use the same test every time: results from different tests aren’t directly comparable.
How accurate is a time trial for MAS?
For most team-sport athletes, a well-paced, all-out time trial gives a sound estimate of MAS. It depends on pacing and effort, so treat the result as an estimate, and retest the same way each time so the numbers compare.
Which time-trial distance should I use?
Anything from 1.2 to 2.2 km, in 200 m steps. Pick the distance that most of your squad finishes in about 6 to 8 minutes, then use that distance every time you retest.
Why not use the Yo-Yo IR1 final speed as MAS?
Because it tends to overestimate MAS, by about 0.5 km/h in Nathan’s research. The test is intermittent, with recovery between shuttles, so athletes reach a final speed above the speed at which they reach VO2max. The calculator converts the total distance covered instead.
Is MAS the same as VO2max?
No. VO2max is how much oxygen an athlete can use. MAS is the running speed at which they reach it. Two athletes with the same VO2max can have different MAS values, because they run with different efficiency.
How do I use MAS for a whole squad?
Test everyone, then group athletes with similar MAS values and prescribe each group its own speeds. The MAS Conditioning Spreadsheet Package does this from one roster, and conditiond does it automatically for every session.
References
- Bellenger CR, Fuller JT, Nelson MJ, Hartland M, Buckley JD, Debenedictis TA (2015). Predicting maximal aerobic speed through set distance time-trials. European Journal of Applied Physiology 115(12):2593–2598.
- Heaney N (2012). Comparison of a Yo-Yo Intermittent Recovery Level 1 test and VO2max test as a determination of training speeds and evaluation of aerobic power. Honours thesis, Australian Catholic University.
- Heaney N, Williams M, Lorenzen C, Kemp J (2009). Comparison of a Yo-Yo Intermittent Recovery Level 1 test and a VO2max test as a determination of training speeds and evaluation of aerobic power. ASCA conference poster.
- Baker D, Heaney N (2015). Normative data for maximal aerobic speed for field sport athletes: a brief review. Journal of Australian Strength and Conditioning 23(7):60–67.