Could someone tell me what all is involved when you work out "too hard" and get into anaerobic versus aerobic. I know it means you are working too hard and burning carbs, not fat. But how can that be? How does that work when i have always thought, calories in/calories out? Does that mean i can go slower on the elliptical and burn more fat? It just seems backwards.

Pardon my thick headedness.

You're not thick headed at all - in fact, you're right. It really IS calories in versus calories out and you indeed burn more total calories at a higher intensity of exercise than lower. Sure, you burn a higher percentage of calories from fat at low intensities but you burn more total calories at higher intensities. Did you know that you actually burn the highest percent of calories from fat when you're lying in bed? Even so, I don't think it's going to do much for anyone's weight loss. So no, you're not going to burn more fat by slowing down on the elliptical. The whole idea of a 'fat-burning zone' is a myth.

'Anaerobic' simply means that you're working above 90% of your max heart rate and that's very difficult to do for a sustained period of time, like more than a minute or two. For our purposes - fat loss - keep your heart rate somewhere around 70 and 85% of your maximum heart rate. The higher the intensity, the higher your heart rate and the more calories you're burning.

Meg, can you come around to my gym and smack the trainers around the head please? There's a couple that tell me "I'm working too hard" and I'll have more success if I work out at a lower intensity........

Thanks for explaining it so well!