Step one: Sign up for your WH+ Premium membership ... The program includes HIIT workout days, active recovery days with optional steady-state cardio or yoga, and a group fitness day.
Today we're going to do a High-Intensity Interval Training workout, or HIIT, H-I-I-T. What we'll do is 20 seconds of an exercise, pushing as hard as you can, then taking 10 seconds' rest.
SIT is, in fact, a type of HIIT. Sprint interval training refers to exercise routines where you run as hard as you possibly can (or nearly as hard) for a short time, typically 30 seconds.