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.

[Dial_tone]

Originally Posted by 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.

Well you've got two potential forces at work here:

Losing muscle because your body is breaking it down for energy and
Losing muscle thru atrophy because you're not under enough stress to maintain it.

I would think at 3,000 calories the first would not be a problem at all. Personally I tend to lose strength before size.

[harlequinbkk]

um, I seem to remember reading somewhere that muscle atrophy is the body breaking down the proteins in the muscles to provide energy, like when someone is starving and the body is "eating itself". I am not sure how this applies to a healty, well fed person though.

[g_samsa]

Originally Posted by harlequinbkk

um, I seem to remember reading somewhere that muscle atrophy is the body breaking down the proteins in the muscles to provide energy, like when someone is starving and the body is "eating itself". I am not sure how this applies to a healty, well fed person though.

agreed. You're not going to lose any muscle from running 5k's and a half marathon if you're getting enough food at the same time.

I have to say, and it's not specificly a response to your question, that I find it a little funny when people start talking about their muscles dissapearing from running 20 miles a week. I've heard people tell me they plan on running long distance and are concerned about their muscles shrinking untill they look like a batan death march survivor. Then I ask them how far they consider to be long distance. They say 20-30 miles a week. Kinda funny. You have asked a very legitimate question though. You're asking a scientific question which is totaly legit, so I'm not lumping you into that group.

All I can tell you is that as long as you are eating enough calories and continuing to do your routine the same as usuall you wont lose muscle from a little running.

Now, it is very possible to lose muscle from running if you plan on doing long distance. Definition of long distance is somewhere around 50-70 miles a week. Then you're going to have problems maintaining your musclature. Above 70 miles a week and you're going to look like a legit marathoner. There are exceptions that that of course. I know of a guy who runs ultra-marathons of over 100 miles and is 5 foot 9 200 pounds. He's just a freak of nature though.