Originally Posted by Antonio Centeno
Extend your cardio past 45 minutes to a solid hour. That's were you really start to burn fat.
This is simply not true. There is a point where your body switches to burning fuel from fat stores, but it's not at an hour- it's usually around 2000 calories, or 20 miles. This is what marathoners call "hitting the wall".
That doesn't mean that you shouldn't do an hour cardio, by all means, go ahead- but you're not going to magically burn fat at this level. You're just going to burn the additional calories that you would expect to burn running 15 minutes extra-maybe about 100-150, depending on your speed.