This is question which worries me most . I often see whenever I am training for Long distance running on Treadmill at GOLDs Mulund , the Trainer warn me of muscle loss and to do less of running ( Perhaps most Gym Trainers are mooted this thing during their training days ) . Also , the muscle loss (Catabolism ) happens if there is no protein intake and spiced up with proper weight training .

I do take hydro whey and egg whites to maintain my protein balance , but still loose lot of muscle which I come to know during my Bimonthly body analysis .

Need some gyaan from the group on the subject.

Cheers !