Running and muscle atrophy

[03gt]

At what distance or calorie expenditure does someone's body use muscle for energy? I am 6'2", 205 lbs, don't know body fat, and take in about 3000 healthy calories a day. Sorry if this question is too vague. Reason I ask is because I am about done with the muscle building phase and about to cut 10-15 lbs. I do 5ks here and there and will be doing a half marathon in April. Thanks in advance.

 

[bluetortilla]

It all depends on the individual and metabolism but at your height and weight you should lose weight if you're running a lot and are taking in 3000 calories. I don't know about running (do a search) but in hard cycling I take in 400 calories per hour to maintain energy so that should say something.

I'm the same height as you but weigh only between 170-175. On really active days I'll take in up to 3500 calories with no weight gain.