How much is too much?

[muay thai chris]

First off, I've been a lurker for a long time and this is my first time posting. You guys have been a great source of information but there is one question I couldn't find the answer to. In the last year and a half I've gone from 6'1" and 155 lbs. (I know pretty skinny) to 6'3" and 195 lbs. So i would really like to keep as much muscle as I could but my conditioning needs more work. I've been told that conditioning too much will cause a loss of muscle mass. So my question is first off is this true? Also, if it is what is the best way to prevent it and is 30 minutes of intense running too much?

PS I currently have a resting heart rate of 67 and would like to get it under 60 just so you know my goals

[Revok]

Don't believe everything you read on t-nation. You will not turn into a withered little girl should you ever attempt to run for more than five minutes straight, especially not at the relatively normal weight of 195.

67 is a pretty below-average RHR. Sounds like you don't have an aerobic base, and also that you don't have much structure in your approach to running. To start with go to the nearest park and run around it for as long as you possibly can, doesn't matter how slowly. Then top it off with some sprints. Maintain your current calorie intake, down a protein shake afterwards, and you won't lose a pound in muscle.

http://www.rrca.org/publicat/base.htm

http://www.trifuel.com/triathlon/tri...ter-001091.php

http://www.coolrunning.com/engine/2/2_3/181.shtml

http://www.lehigh.edu/dmd1/public/www-data/sarah.html

[Tom P]

You wont lose muscle as long as you eat enough. The whole deal with muscle loss is when some one is trying to lose fat, they eat less, which is causing the muscle loss.

[Qester]

Originally Posted by Tom P

You wont lose muscle as long as you eat enough. The whole deal with muscle loss is when some one is trying to lose fat, they eat less, which is causing the muscle loss.

This is no particularly true. While doing long distance running muscle protein is one of the fuels that is used to provide the body with energy (which will result in a lbm decrease). Although the amount of protein used if one is eating a diet with caloric surplus won't be gigantic.

[Ogun]

Aerobic running does consume some muscle, and moreover encourages the conversion of some fast-twitch muscle to slow-twitch. Once or twice a week of a reasonable amount of aerobic running is no big deal. Other days, stick with HIIT: it burns more fat, preserves muscle and encourages muscle growth.