T Nation

Low Blood Sugar, Fat Loss

At what point does the body start burning fat as fuel?

We are told to do aerobic exercise first thing in the morning on a empty stomach

Is fat burnt when the bodys blood sugar drops below a certain point?

[quote]ss2handyman wrote:
At what point does the body start burning fat as fuel?

We are told to do aerobic exercise first thing in the morning on a empty stomach

Is fat burnt when the bodys blood sugar drops below a certain point?[/quote]

You are always burning fatty acids for energy. The body is never in a state where it it burning only one substrate for energy.

[quote]ChrisKing wrote:
You are always burning fatty acids for energy. The body is never in a state where it it burning only one substrate for energy.[/quote]

I second this.

The real question should be - at what point does it stop burning fat and start looking for other sources, i.e. lean tissue? From what I’ve read, this occurs when your body steps out of aerobic and into anerobic exercise. Basically exercise that gets your heart rate above ~80% max or something very strenuous like weight training. I have my reservations that weight training alone will cause this, as I would think it would have to be particularly challenging workout to reach that point.

I do not believe it is related to blood sugar at all.

What are you specific concerns? Are you just trying to maximize the fat burning?