No sweat no gain is a misnomer. Actually, you can gain muscle mass though heavy lifting with long periods of rest. No sweat. With rest there is no cardio, no elevated heart rate, no sweat.
Sorry, couch potatoes, finishing off a 20 pack of Bud Lights on Superbowl Sunday does not make you stronger, drunker yes.
But the good news is you sweat with those frequent trips to the commode during commercials. This counts for cardio if you run, extra points if someone is in the bathroom and you have to jump up and down while holding it.