How the calculator works

Put in a race you’ve run properly in the last six to eight weeks. The calculator turns it into a fitness score called VDOT, the system Jack Daniels built his training around, then works back from that score to what you could run over other distances and the paces your training should sit at.

A parkrun is perfect. One you jogged round chatting is not. If the course was hilly, knock a few seconds off in your head. Not all parkruns are equal and anyone saying otherwise hasn’t run Barnsley.

Why your marathon time might look slower here

Most calculators assume you’ve done the endurance work to hold a pace for 26.2 miles. Plenty of runners haven’t, and the marathon is where that shows. So I ask for your weekly mileage. Under 45 miles a week, I add a bit to the half and the marathon, so the number you get is one you can actually run, not one that falls apart at 20 miles.

I learned that one the hard way. Hull 2015, on for sub 3, crumbled at 13 miles. A year of proper mileage later I ran 2:51 on the same course.

Using your seven paces

• Recovery. The day after a hard session or long run. Slower than you think, and that’s the point.
• Easy. Most of your week. If your easy days and session days are within thirty seconds a mile of each other, you’ve lost the difference that makes you faster.
• Steady and Marathon. Long run work and race specific sessions when you’re building for a half or a full.
• Threshold. The engine room for every distance. Comfortably hard, a few words at a time.
• Interval and Reps. The quick stuff, kept small. A little goes a long way.

Redo it every couple of months. Paces from a race last February aren’t your paces now.

Want them built into a plan?

The calculator tells you the paces. A plan tells you what to do with them, week by week, around the days you actually have. Every personalised plan I write uses your own times, and 1:1 coaching rewrites it as life gets in the way. I ran 2:24:35 around a full time job, so I know how that bit works.