Interval Challenge Today we're going to test each of the energy delivery systems by performing intervals of varying lengths. So instead of a fixed 30-second interval, we'll be doing everything from 10-seconds through 2 minutes. Make sure you have a timing device or a partner to call out the intervals.
Interval times are in the reps field in seconds for this workout.
After your break, start again, but this time go in reverse order. So you'll go 10, 15, 20, 30, 60, 120 seconds per interval.