I get a few emails a week (via the contact form) asking about what and when to eat for optimal HIIT results.

I tend to reply to this kind of question with a list of pro’s and con’s and no concrete advice either way. I do this because it is a heavily debated topic and you will find a million people who will say eating before hand is good and another million who say that NOT eating (fasted cardio) gives best results.

The problem with this debate is everyone is different, not to mention everyone has different goals. Bodybuilders are generally more concerned with keeping their hard earned muscle, whilst people with weight loss goals and cardiovascular health in mind are typically worried about burning fat.

I’ve seen both work for people, and I’ve had both work for me, and I still can’t say for sure which way was better.

It’s a kind of damned if you do, damned if you don’t situation.

On one hand, if you chose NOT to eat before your HIIT workouts, such as in the morning before breakfast, you will quickly deplete your glycogen stores and move straight into utilizing fats for fuel.

On the other hand, if you have your breakfast you will have more energy to workout harder and longer and therefore burn more calories and boost your EPOC, resulting in a metabolism increase.

So there you have it, I’ve given no real answer. My only recommendations is that you try both. Muscle can be gained, and fat can be burned so there is no real risk in giving both methods a trial. The most important thing to remember is some cardio is better than no cardio at all, so chose whichever option leads to you working out more often.

Got something to say on the issue? Head over to the HIIT forums and let me know.