10000m Alternate R18/22 Split length 1250m. R18 at 2km plus 20. Increase 4-5s for the R22 2K plus 20 means that the pace for 500m shown on the monitor is 20 seconds slower than their average pace for their fastest 2000m effort (so for a 8:00 2K – the average would be 2:00 – therefore 2km plus 20 would be 2:20/500m)