Tool · Physiology
MAS calculator (maximal aerobic speed)
Estimate your maximal aerobic speed (MAS, or vVO₂max) from a recent race, a 6-minute half-Cooper test or a progressive stage test. You also get your VO₂max (VDOT index), your 7 pace zones and your predicted race times, with the same calculations as RunMorph plans (Jack Daniels method).
Your MAS is a field MAS: the speed you can hold for about 6 minutes all-out, the one measured by the half-Cooper and VAMEVAL tests. The VO₂max shown is Jack Daniels’ VDOT index, on the same scale as in RunMorph (range of about 36 to 44 ml/kg/min). These values are estimates and are no substitute for a lab test. In your RunMorph account, the half and full marathon are also adjusted to your actual training volume (weekly distance and longest run): at low mileage, they come out slower there than here.
Show my 7 pace zones
| Pace zone | % MAS | Pace |
|---|---|---|
| Z1 · Recovery | 55 to 65% | 10:46 to 12:43 /mi |
| Z2 · Easy endurance | 65 to 75% | 9:20 to 10:46 /mi |
| Z3 · Tempo / marathon pace | 76 to 83% | 8:26 to 9:12 /mi |
| Z4 · Threshold | 84 to 92% | 7:36 to 8:20 /mi |
| Z5 · MAS | 95 to 100% | 7:00 to 7:22 /mi |
| Z6 · Anaerobic capacity | 102 to 110% | 6:22 to 6:52 /mi |
| Z7 · Speed / sprint | over 110% | faster than 6:22 /mi |
How to calculate your MAS
Your MAS (maximal aerobic speed, also known as vVO₂max) is the speed at which you reach your maximal oxygen uptake (VO₂max). Here it means your field MAS, the speed you can hold for about 6 minutes all-out: the baseline for setting all your training paces. Three methods let you estimate it without a lab:
1. From a race time (VDOT method, the most reliable)
Start from a recent performance over a known distance. Jack Daniels’ VDOT model derives your equivalent VO₂max (the VDOT), then the speed you could hold for about 6 minutes: your field MAS. It’s the calculator’s default method. Example: a 10K in 50:00 (7.5 mph on average) gives a MAS of about 8.6 mph (13.8 km/h), a pace at MAS close to 7:00/mi.
2. The half-Cooper test (6 minutes)
Run all-out for 6 minutes, ideally on a 400 m track, and measure the distance covered:
Example: 1,450 m in 6 minutes → MAS = 1,450 ÷ 100 = 14.5 km/h, or 9.0 mph.
3. A progressive stage test (VAMEVAL, Léger-Boucher)
Stage tests are progressive field tests paced by a soundtrack of beeps. You run around a track marked with cones and must reach each cone on the beep. The speed goes up in regular stages until you can no longer keep up: the speed of the last stage you fully completed is your MAS. That’s their appeal: they measure MAS directly, with no race time and no formula.
- VAMEVAL (developed by Georges Cazorla): cones every 20 m, starting at 8 km/h, then +0.5 km/h every minute. Small increments and close cones make it the most precise stage test, and the one running clubs use most.
- Léger-Boucher: cones every 50 m, starting around 8 km/h, then +1 km/h every 2 minutes. Older and a little less fine-grained (longer, more widely spaced stages), but the principle is the same.
Either way, enter the speed of your last completed stage in the calculator. If you stop mid-stage, use the previous one. These tests are usually run on a track, at a running club, with the official soundtrack. Don’t confuse them with the 20 m shuttle run (the “beep test”), which is mainly designed to estimate VO₂max.
Whatever the method, the pace for a given speed is pace (min/mi) = 60 ÷ speed (mph).
MAS chart: training paces
Key paces based on your field MAS, with the zone table of RunMorph plans: Z5 for MAS sessions (95-100%), Z4 for threshold (84-92%), Z3 for tempo and marathon pace (76-83%), Z2 for easy running (65-75%).
| MAS | Z5 MAS | Z4 threshold | Z3 tempo / marathon | Z2 easy |
|---|---|---|---|---|
| 7.5 mph | 8:00 to 8:25 /mi | 8:42 to 9:31 /mi | 9:38 to 10:32 /mi | 10:40 to 12:18 /mi |
| 8 mph | 7:30 to 7:54 /mi | 8:09 to 8:56 /mi | 9:02 to 9:52 /mi | 10:00 to 11:32 /mi |
| 8.5 mph | 7:04 to 7:26 /mi | 7:40 to 8:24 /mi | 8:30 to 9:17 /mi | 9:25 to 10:52 /mi |
| 9 mph | 6:40 to 7:01 /mi | 7:15 to 7:56 /mi | 8:02 to 8:46 /mi | 8:53 to 10:15 /mi |
| 9.5 mph | 6:19 to 6:39 /mi | 6:52 to 7:31 /mi | 7:37 to 8:19 /mi | 8:25 to 9:43 /mi |
| 10 mph | 6:00 to 6:19 /mi | 6:31 to 7:09 /mi | 7:14 to 7:54 /mi | 8:00 to 9:14 /mi |
| 10.5 mph | 5:43 to 6:01 /mi | 6:13 to 6:48 /mi | 6:53 to 7:31 /mi | 7:37 to 8:47 /mi |
| 11 mph | 5:27 to 5:44 /mi | 5:56 to 6:30 /mi | 6:34 to 7:11 /mi | 7:16 to 8:23 /mi |
| 11.5 mph | 5:13 to 5:30 /mi | 5:40 to 6:13 /mi | 6:17 to 6:52 /mi | 6:57 to 8:02 /mi |
| 12 mph | 5:00 to 5:16 /mi | 5:26 to 5:57 /mi | 6:01 to 6:35 /mi | 6:40 to 7:42 /mi |
These paces are ranges as a percentage of field MAS. The calculator above gives your 7 zones (Z1 to Z7) from your own result.
Frequently asked questions
What is MAS in running?
MAS (maximal aerobic speed, also called vVO₂max) is the running speed at which your body uses the most oxygen it can (your VO₂max). It’s a reference speed: expressed in mph or km/h, it gives you every training pace, from easy runs to intervals. The MAS used here, as in RunMorph plans, is the field MAS: the speed you can hold for about 6 minutes at maximal effort, the one measured by the half-Cooper and VAMEVAL tests.
How can I work out my MAS without a lab test?
Three simple methods: (1) from a recent race time (5K, 10K, half…), using Jack Daniels’ VDOT index, the most reliable; (2) with the half-Cooper test: run all-out for 6 minutes, and MAS (km/h) = distance covered in meters ÷ 100; (3) with a stage test such as VAMEVAL or Léger-Boucher, where the speed of the last stage you complete is your MAS. This calculator handles all three.
What’s the difference between MAS and VO₂max?
VO₂max is an oxygen uptake (in ml/kg/min); MAS is a running speed. The rule of thumb “VO₂max ≈ 3.5 × MAS (km/h)” gives a ballpark figure. The calculator uses Jack Daniels’ VDOT index instead, which factors in your running economy and links MAS, VO₂max and race times on one scale: a MAS of 15 km/h (9.3 mph) matches a VDOT of about 44 ml/kg/min.
What is MAS used for in training?
It sets the intensity of every session. With RunMorph’s zone table: easy running at 65-75% of MAS, marathon pace around 76-83%, threshold at 84-92%, MAS sessions at 95-100%, and shorter repeats at 102-110%. Knowing your MAS stops you from running your easy days too fast and your hard sessions too soft.
How often should I recalculate my MAS?
Every 6 to 10 weeks, or after a benchmark race. MAS improves with training (especially for newer runners), then levels off; recalculating it regularly lets you adjust your paces so you keep improving without getting hurt.
Turn your MAS into a training plan
RunMorph works out your 7 pace zones from your MAS and builds a session-by-session plan, periodized all the way to race day.
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