Racing smarter

What pace is a 20-minute 5K?

What pace is a 20-minute 5K?

20:00 over 5 km (3.11 mi) is 4:00/km (6:26/mi), held from the first step to the last. There is no rounding slack in that number: run the first kilometre at 4:10/km and you have already spent ten seconds you will not get back cheaply.

Sub-20 is 4:00/km (6:26/mi) and it is the benchmark that defines a whole tier of parkrun ambition. It needs real speed work, not just volume: most people who get there are running intervals at 3:45 pace weekly on top of 40 to 55 km. The race itself is almost pure discipline. Twenty minutes at this intensity gives you no recovery, so the first kilometre decides it. Start at 3:52 because the crowd is fast and you feel good, and the fourth kilometre will be 4:15. Start at 4:02, hold 4:00 through 3 km, and you will have something left for the last 800 metres, which is where sub-20 is actually won.

What the splits look like

And in miles, for a course measured that way:

Where should I be at halfway?

Even pace puts you through halfway at 10:00. Most people who finish this time went through slightly slower than that, not faster — a 2% negative split means halfway at 10:12 and a second half of 9:48.

The decision rule for race day: if you reach halfway more than 0:12 ahead of 10:00, you are not ahead of schedule, you are borrowing. Ease back to 4:00/km (6:26/mi) and hold it.

What if my watch measures the course long?

Almost every watch does. A 5K that reads 1.5% long on your wrist means you have to run 3:56/km by the watch to finish in 20:00 by the clock. That is the pace to put on the screen, and it is why pacing off a watch's average-pace field alone tends to leave people a minute or two short.

See this on your own runs →