Variable Time 3x 10 min cont. (4m/3m/2m/1m) rest 3-6min 63 & 67% start rates 2x 22/24/26/28, then 1x 24/26/28/30 Start targets = 2k PB pace +15-16 at r22, and +13-14 at r24. Increase pace at least -2 seconds (~3%) from previous with each rate increase.