Have a scoop of whey in water before your cardio.

i do mine on an empty stomach..never had any problems with muscle loss...unless ur genetically predisposed to losing muscle easily then have some whey before hopping on the tread...Also go by the mirror, do u look like ur shrinking, not leaning out, but shrinking...do ur muscles look full or flat? are ur carbs high, low..these are all factors to look at...But do whats rite for u, and always go by the mirror.

pudge