I would definitely wear shoes. I did 30 Day Shred, Fat/Metabolism, and Trouble Zones on and off for a year. Recently, I had to stop in the middle of an exercise because I couldn't put any weight at all on my left foot; I ended up spending two weeks in a boot. Now I wear gel inserts in my inside only tennis shoes (I live in NYC, so I have dirty outside shoes and inside only shoes). Some of the moves force you to put a lot of pressure on your heels, so I would suggest wearing shoes even if you're doing the exercises on carpet.