Prescribing running off a stopwatch and a hunch only gets you so far. This free calculator takes one time-trial result and turns it into an athlete's maximal aerobic speed, then hands you the running speeds and cone distances to build your intervals around. No spreadsheet, no guesswork.

What is MAS:
Maximal aerobic speed is the slowest running speed at which an athlete reaches their maximum aerobic capacity. In plain terms, it is a single, individual anchor for running fitness. Once you know it, you can set every interval, tempo and repeat as a percentage of that athlete's own speed, rather than running the whole squad at one pace that is too easy for some and too hard for others.

How to use it:

1. Pick your test. Choose a method you have a result for: a 1.2 km or 2 km time trial, the Bronco, a 6 minute run, or a custom distance and time.

2. Enter the result. Punch in the distance and the time.

3. Read your MAS. You get maximal aerobic speed in km/h and m/s, with a matching pace per kilometre.

4. Build your session. Use the percentage of MAS table to set your target speeds, and the interval distance table to know exactly where to place your cones for 15, 30, 45 or 60 second efforts.

What you get:

• MAS in km/h, m/s and pace per kilometre

• A full percentage of MAS table, from easy aerobic work up to supramaximal efforts

• Interval distances you can set cones from straight off the screen

• A fast, repeatable way to individualise conditioning across a whole squad

Who it is for:
Built for sports physios, strength and conditioning coaches, and any coach who wants to prescribe running properly. It works just as well for return to running progressions as it does for day to day conditioning.

Want it on paper?

Grab the FREE printable MAS protocol and calculator sheet from the store, with the time-trial set-up, the lookup tables and conditioning guidance ready for the training ground. And if you like this, the full Standardised Testing Series has a sheet for every test worth running.