This will get you looking better in that bikini for the summer! Looking how to properly do high intensity interval training? Here is the best and most effective way to perform HIIT High Intensity Interval Training on the treadmill. This is a great way of training to lose fat the most efficiently and as fast as possible. You’re going to be burning calories up to 36 hours later and HIIT training is 9 times more effective than standard steady state cardio.