sure. It means I have not eaten yet when I do my cardio. I'm on this plan fast-5, I don't start eating until 2-3 pm. So I am testing the "cardio on empty" burns fat better theory. it's a body builder technique and supposed to be good for someone with a high bf% such as me. 34-35% right now.
it's controversial--but I don't care.
Here is a study about it..just one little one:
"A study carried out at Kansas State University (Wilcox, Harford & Wedel Medicine & Science in Sports and Exercise, 17:2, 1985), indicates that a kilogram of fat will be oxidized sooner when exercising in the fasted condition in the morning than when doing the same exercise in the afternoon. By measuring respiratory gas exchange, caloric expenditure, and carbohydrate and fatty acid metabolism, these researchers showed that the mass of fat burned during aerobic exercise amounts to 67% of the total energy expenditure achieved when the same exercise is done later in the day or in the fed state."
Wow jendiet! That sounds really hard. I don't think I could do cardio without eating. Or much of anything if I wasn't eating until 2 pm. That sounds like a hard plan to me. How long have you been doing it? I'll take my WW any day over a plan that doesn't allow me to eat when I wake up!
It's actually not that hard. I've been doing it since June 16, 2009 and I have lost 12 lbs. Most of all I have really lost fat! from 37% to 34% in a month. so I am pleased with it.
The fast 5 doesn't require the cardio on empty--I just threw it into my routine.
I know I would exercise less without this thread holding me accountable. 
