Start slow
Go all out for 20 seconds, and then recover for 40 or even 60 seconds. You may feel like that’s not hard enough, but building up slowly will decrease your risk of injury and prevent you from burning out.
Don’t skip your warm-up
Because you’ll be racing through moves, it’s important that your body is primed for action.
Warm up all your major joints (neck, shoulders, wrists, hips, legs, and ankles) with circular movements. Then move on to jumping jacks or a light jog in place or on a treadmill.
Aim for reps
If you’re looking to improve (and who isn’t?), keep track of your reps during a given interval and try to beat it next time.
For instance, if you’re doing Tabata, aim for 20 bodyweight squats in 20 seconds.
Use an interval timer
If you’re working as hard as you should be, it’s going to be tough to keep it together while glancing at a watch, a wall clock, or your iPhone.
Instead, use an interval timing program. You’ll set it once, press start, and get to work.
Don’t train on back-to-back days
At most, try HIIT two or three times per week on nonconsecutive days. On non-interval days, do some steady-state cardio or try another type of training, like yoga or Pilates.
Just add weight
If you need to make your workout harder, add weight to any body-weight movement or add more weight during the first round of a circuit.
Keep the intervals short
Your intervals shouldn’t be minutes long, they should be seconds long — ideally 20 to 60 seconds.
Remember: The intervals are short so you can push yourself to the max. “The shorter a workout is, the more I dread it!” .
Use the “talk test”
Not sure if you’re pushing yourself? During the intervals, you shouldn’t be able to speak in full sentences.
Work out with a partner
Alternate your work and rest intervals with a partner You’ll rest while your partner works, and vice versa. While “resting,” your job is to cheer on your partner and keep them working extra hard.