HIIT also works with strength training, not just cardio-oriented stuff. 30 min workout per day, 3 sets of the heaviest weight you can handle, highest exertion

HIIT also works with strength training, not just cardio-oriented stuff. 30 min workout per day, 3 sets of the heaviest weight you can handle, highest exertion you can muster, with a couple different exercises. Our bodies respond well to extreme variation in exertion, and HIIT strength training is another way of accomplishing that besides HIIT cardio.