THE GREATEST HIITS
Top instructors at two treadmill studios give simple interval routines.
1 40-minute hill climb
Warm up at an easy pace for 5 minutes, then do a 2-minute hill interval (choose a 4 to 7 percent incline) at hard effort, followed by 2 minutes at a recovery jog or walk on a 1 percent incline. Repeat combo, this time doing a 3-minute hill interval, with a 2-minute recovery. Do the next 2 hill intervals at 4 minutes each, with a 2-minute recovery. Finish with 2 more hill intervals, first a 3-minute interval and then a 2-minute interval, each with a 2-minute recovery. Cool down with a 5-minute walk. —Elizabeth Corkum, Mile High Run Club studio in New York City
2 25-minute sprintervals
Warm up at an easy jog for 10 minutes. Next, complete 60 seconds on (that is, at a challenging fast running speed), then 60 seconds off (easy-paced recovery). Repeat 3 times, decreasing the recovery by 10 seconds each time: 60 on, 50 off; 60 on, 40 off; 60 on, 30 off. Recover at an easy jog or walk for 1 to 2 minutes. Do five 30-second sprint intervals: 30 on, 50 off; 30 on, 40 off; 30 on, 30 off; 30 on, 20 off; 30 on at an all-out sprint. Cool down for 5 minutes. —Becs Gentry, an instructor at the new Peloton Tread Studio in New York City