I was in an induced coma for a couple weeks, and intubated in the ICU for a total of about 30 days. When they deintubated me my breathing muscles were so weak I thought I would die of asphyxiation. They sent me home a few days later, as soon as I could climb a staircase (there were stairs leading to my front door).
Several days after returning home I got stuck in the bathtub: I couldn't lift myself out, my wife couldn't lift me. After several false starts, we got me out by me lifting up a couple inches, and my wife shoving a pillow under my butt, several times. :-)
I was back at (office) work 2.5 months later, and biking to work 3 months after that.
All of which to say: 100% agreed -- do absolutely nothing and the body just wastes away.