45min Catabolic Barrier

Some old man in the gym was talking to me about a 45min Catabolic Barrier.

As in, once you get to the gym, or start working out, you have approx. 45minutes before you're body turns catabolic and starts feeding on muscle tishue.

Has anyone heard of this before, or is he just a confused old man?

i thinnk he might have his info a bit messed up, first your body goes to carbs because there easy to convert to energy then it goes to fats then proteins. see your body goes to the quickest sources of fuel first and the easiest to convert. breaking down muscle would require alot of work within the body. Maby this might occur if you had a shit poor diet and you did not get the proper nutrients and sources of food and you body had to break down the body tissue to create simpler substances for it to use. I just think this theory he told you might be off, but i am no doctor and this is only my opinion!!!