High Intensity Interval Training (HIIT) is one of the best and most effective ways to get in shape fast. HIIT requires alternating periods of very intense, all-out effort with lower intensity (or rest) sessions during which time you’re able to recover. HIIT can be very difficult when done for the first time, so make sure to go at you own pace and stay hydrated!
Some people do HIIT first thing in the morning and on an empty stomach in order to deplete carbohydrates store faster, and begin using fat as fuels sooner in the exercise session. True, however; in my opinon this type of workout is so intense that you SHOULD eat something before – something small though: a piece of fruit or a shake. Otherwise, you may not have enough strength and energy to go thru the session. Therefore, making your workout NOT as efficient as it could be. Your post workout ‘recovery’ meal should include not only carbohydrates and protein, but also essential vitamins and minerals.