Wake up to your workout

I hope you're a morning person, otherwise my advice is going to be a little painful.

Good news for all those up-and-at-'em early risers. The best time of day to achieve maximum fat loss is first thing in the morning, before we've eaten.

That's when our bodies' glycogen levels are at their lowest. And that's important because normally, glycogen is our number one source of energy.

However, when our glycogen stores are low, the body turns to its number two energy source: fat.

But if fat loss is what you're after, how you train is as important as when. So more of a rude awakening for everyone who starts the day with all the energy levels of a sedated koala - the quickest results come from high-intensity interval training.

What is it? Well, if you've ever done a British Military Fitness workout, or watched those poor souls lugging a tractor tyre on Biggest Loser, that's HIIT. A less outdoorsy example would be the "hill climb" setting on the cardio machines in the gym. With HIIT, it's important that you replace the glycogen in your muscles as soon as possible after your workout.

The best way to do this is to eat simple carbohydrates: apples, blackberries, blackcurrants, grapefruit. Best of all, after a good morning's session, the muscles are so deprived of carbs that it's about the only time of day when the old adage "a moment on the lips, forever on the hips" doesn't apply.