David's instructions said 90 minutes ("90 min easy. Just run/walk, take photos, and relax. Want you rested for the race"), but since I'm doing hot yoga at 8:45 and since my legs really feel tired (plus always that annoying tendinitis-y feeling on right hamstring) I decided an hour would be quite enough. A pyramid scheme!
3 x 20:00 as (1) easy warmup (4:1) (2) UP! 1/1/2/1/3/1/4/1/5/1 (one-minute rest as walk interval) (3) DOWN! 5/1/4/1/3/1/2/1/1/1