Breakthrough Sessions – 24 minute 5k. 400m Reps – these need to be at 7:41 p/m pace (1:54 per lap) with a 60sec standing recovery. 800m Reps – should be reps at 7:41p/m pace (3:48 per 800m) with a 200m jogged recovery. 1km Intervals – hit 7:41p/m pace (4:46 per km) with a 90sec jogged recovery. I guess from a conversion from a 5km to a 10km, I look at the slowing down at about 3%. So if we work out your average pace and we multiply that by 3% that would give you a reasonable idea for a 10km. When we convert that from a 10km to a 21km you’re looking at maybe another 3% or possibly 4%, somewhere around there. 10k race pace Threshold pace Marathon race pace Long run pace How to run a 5k in under 20 minutes © Copyright Craig Wallace It’s just another number, 20. But like many running benchmarks, it is a popular target, and to run under 20 minutes for 5k is what many would say defines a ‘serious runner’. To calculate your pace per kilometer, measure the distance you covered and the time it took to complete the distance. Divide the time taken by the distance covered to get your pace per kilometer. For example, if you covered 5 km in 25 minutes, your pace per km would be: Pace = Time taken / Distance covered. Pace = 25 min / 5 km. In the remaining columns the times to travel different distances keeping the same pace are calculated. For example, a 6'00"/km running pace corresponds to a speed of 10 km/h. Keeping this pace you can run a half marathon in 2h06'35" or a marathon in 4h13'10". TABLES NOTES: HM: half marathon (21.0975 km / 13.1 mi). Running 5K in less than 20 minutes requires running at 6:26 pace for 3.1 miles (5.0 km). You need to be able to run at least a 6:00 mile before you run this 5k in under 20 minutes. This alone still won't guarantee you your goal time. You must train regularly. w1ck.