We have no carpeted flooring in our house and decided to purchase padded interlocking tiles for when we want to do floor exercises, such as abdominal crunches. I found the exercise tiles at the exercise equipment stores. They were nice quality but pricey for our home needs.
We then checked the exercise section of a local department store as well as the automotive section. The same interlocking carpeted floor mat was much less in the automotive section than in the exercise section. One was labeled as a exercise mat and the other was labeled as floor tile for a shop or garage. We went with the automotive section version for a lot less money.