IMPROVISED INDOOR HIIT – 1
1) treadmill turned off, using handle bars to brace yourself with head down and back flat, sprint as hard as you can using leg drive manually moving the treadmill belt for 15-20 seconds. Rest-30 seconds rest (20 reps). 2) WOMEN: treadmill: 10 incline, 7 mph (sprint for 15, rest for 30) 20 reps .