2500m x 4 R18 (rest 2m) 2km plus 20 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)