One of the biggest crazes at the moment is HIIT [High Intensity Interval Training]. It is being sold as the best exercise for fat loss!
The people pedalling this as the magical fat loss protocol are, well, massively overselling it.
Will you burn the maximum amount of calories for the time you are performing HIIT? Yes.
However, this could have a contraindication to fat loss if you are so tired from performing your HIIT session you reduce activity for the rest of the day, therefore reducing total daily calorie expenditure!
Will you create an Excess Post exercise Oxygen Consumption effect [Also known as an after burn]? Yes.
However this is going to be around 7Kcals per hour more than you are normally burning off. Hardly significant and that is only up to a few hours until your body reverts back to normal levels.
Will you increase cardio vascular performance? Yes.
But, it will put a strain on your nervous system and can impact your immune system which, is why the people that are selling HIIT advocate taking a Vitamin C intake after you have performed it!
Will it make you feel good? Yes.
However, all exercise will make you feel good by releasing endorphins [the feel good chemical]. Also if you’re performing HIIT you may be at an increased risk of injury if you are performing impact work.
Integrating HIIT into your exercise regime is OK, in moderation [provided you don’t have a heart condition or high blood pressure], its just not the fat loss fix it is being made out to be.