Maximal Aerobic Speed (MAS) Calculator
Calculate maximal aerobic speed (MAS) from a 1,500–2,000 m or 5–6 minute time trial, in m/s, km/h and pace, with 15/15 and 30/30 interval distances at 90–120% MAS.
How it works
MAS (m/s) = time-trial distance (m) ÷ time (s) · km/h = m/s × 3.6 · interval distance = MAS × % × work time · VO2max ≈ MAS (km/h) × 3.5 (Léger & Mercier)
Maximal aerobic speed is the lowest running speed at which you reach VO2max. Coaches estimate it from an all-out time trial lasting about 5–7 minutes — commonly 1,500 m, 2,000 m or a 6-minute run — because the average speed of that effort sits very close to MAS (Baker, 2011; Bellenger et al., 2015). MAS is then used to set individual interval distances: short intervals such as 15 s on / 15 s off are run at 100–120% MAS, and longer ones at 85–95%.
Worked example
An athlete runs 2,000 m in 8:00 (480 s): MAS = 2,000 ÷ 480 = 4.17 m/s = 15.0 km/h, a pace of 4:00 /km. For 15 s on / 15 s off at 110% MAS each rep is 4.17 × 1.10 × 15 = 69 m; the rough VO2max estimate is 15.0 × 3.5 = 52.5 ml/kg/min.
Sources: Baker D (2011) Recent trends in high-intensity aerobic training for field sports. UKSCA Professional Strength & Conditioning 22:3–8 · Bellenger CR et al. (2015) Predicting maximal aerobic speed through set distance time-trials. Eur J Appl Physiol 115:2593–2598
Frequently asked questions
What is maximal aerobic speed?
The slowest speed at which your oxygen uptake reaches its maximum. Running at MAS can usually be sustained for about 4–8 minutes, so it is a practical bridge between VO2max and training paces.
Which time trial should I use?
Any all-out effort lasting about 5–7 minutes: 1,500 m for slower athletes, 2,000 m for most team-sport players, or a 6-minute run for distance. Shorter trials overestimate MAS because of anaerobic contribution; longer ones underestimate it.
How do I use MAS for intervals?
Multiply MAS by the target percentage and the work time. Typical sessions: 15 s at 100–120% with 15 s rest, 30 s at 95–100% with 30 s rest, or 3 minutes at 85–90% with 2–3 minutes rest.
Is MAS the same as vVO2max?
Essentially yes — vVO2max is the laboratory term for the speed at which VO2max is reached, while MAS usually refers to the field estimate from a time trial or a test such as the Université de Montréal track test.
Related calculators
This calculator gives an estimate for general fitness and education only. It is not a diagnosis — field tests and prediction equations can differ from laboratory measurements, so talk to a doctor or qualified exercise professional before acting on the result, especially before maximal testing.