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Cooper test: how to test your maximal aerobic speed

Kenneth Cooper's 12-minute run, from warm-up to the last lap. What your distance in miles says about your VO2max, and the treadmill speeds it gives you.

Updated

The 12-minute run is an American test. Kenneth Cooper had 115 US Air Force men run as far as they could in 12 minutes, then measured their VO2max on a treadmill, and in 1968 he showed in JAMA that the distance predicted the lab number at a correlation of 0.897.

Nearly 60 years later, it’s one of the standard ways French coaches measure maximal aerobic speed.

Maximal aerobic speed, briefly

Maximal aerobic speed (MAS) is the slowest pace at which you reach your VO2max. French and Canadian coaches build intervals as percentages of it (say 6 × 3 min at 95% MAS), the way US coaches use paces from a recent race. Billat and Koralsztein put the time most runners can hold it at about 6 minutes, give or take 25%.

Twelve minutes is 720 seconds. Blondel’s students lasted 357 seconds on average at 100% of their MAS and 839 at 90%, so a 12-minute average usually lands somewhere between 90 and 100% of MAS. Where you fall in that band varies a lot: the spread was 110 seconds either way at 100% and 236 at 90%.

Running the 12 minutes

A 400 m track is the easy option, because laps are easy to count: seven laps is 2,800 m, or 1.74 miles. A flat loop you’ve measured also works. Skip windy days. On a track you get the wind in your face on one straight and at your back on the other, and they don’t cancel out: Davies calculated that for a runner at 6 m/s, a headwind of the same speed costs as much as a 5.8% grade, and the tailwind only gives it back once the wind reaches 15 m/s, about 33 mph.

Pick a day at least two days after a hard session, after a full night. Souissi’s 20 young runners covered 6% less distance in a 12-minute run after sleeping 4 hours. Heat cuts your distance too. Warm up with 15 to 20 minutes of easy running, a few drills and three or four strides of about 80 m, then walk for two or three minutes before you start.

The pacing is the hard part. Start too fast and you fade; start too slow and you finish with something left. You want an even effort that’s hard by minute three and very hard at the end, then empty the tank over the last 400 m. Your 12-minute pace should come out a little faster than your 5K pace.

To measure, count laps. The best setup is a friend who marks where you are at 12:00, to the nearest 10 m. On your own, note the 100 m marks on the track before you start and stop on the nearest one.

Afterward, walk, then jog easy for 10 minutes. If you feel faint or get chest discomfort during the test, stop.

What your distance says

Cooper’s equation, in its metric form, is VO2max (ml/kg/min) = (distance in meters − 504.9) ÷ 44.73. Average speed in km/h is distance ÷ 200. In miles:

12-minute distance Meters VO2max MAS Pace per mile
1.25 miles 2,012 33.7 6.3 mph 9:36
1.5 miles 2,414 42.7 7.5 mph 8:00
1.75 miles 2,816 51.7 8.8 mph 6:51
2 miles 3,219 60.7 10.0 mph 6:00

Cooper fitted the equation on young, fit servicemen, so the VO2max it returns is a number to track, not a lab result. The Cooper test calculator does the conversion for any distance.

Turning it into treadmill speeds

Take a runner who covers 2,800 m, a MAS of 14 km/h or 8.7 mph. Long intervals sit around 90 to 95% of MAS, so 7.8 to 8.3 mph. Short ones, like 30 seconds on and 30 off, go at 100 to 105%: 8.7 to 9.1 mph, or 400 m reps in 1:43 to 1:38 on the track.

Set the treadmill to a 1% grade. Jones and Doust found that 1% matched the energy cost of road running for efforts of about 5 minutes between 6.5 and 11.2 mph, which covers that whole range.

Shorter tests and beep tests

The 6-minute run, or half-Cooper, is common in France and gets closer to your true MAS: distance ÷ 100 gives the estimate. Step tests raise the speed until you can’t keep up, so the beeps set your pace for you. Léger and Boucher’s track test starts at a walking speed that costs 5 METs, five times your resting energy use, and adds 1 MET every 2 minutes. The PACER from school gym class is a 20 m shuttle version of the same idea.

If you’d rather start from a race than a test, the VO2max calculator gives an estimated VO2max (Daniels-Gilbert) from your finish time.

Retesting

A field test measures the shape you’re in on that day. Run it the same way, on the same track, every 8 to 12 weeks, and compare the distances rather than the VO2max. The training pace calculator turns each new result into session paces.

Sources

Calculators in this guide