You probably don't realise it but there's more than one set of muscles to your abs and many more ways of working them than spending hours doing punishing crunches in the gym. The rectus abdominis is your potential six-pack and the muscle most people are thinking of when they talk about abs, but your abs are made up of three sets of muscles. As well as the rectus abdominis there are the obliques in your side, which come into play when twisting and bending, and the transversus abdominis, which goes all the way across your stomach, behind the rectus abdominis. For maximum toning you need to work all three muscles individually and together rather than just focusing on the easily worked and dominant rectus abdominis. The good news is that there are plenty of exercises you can do without even needing to go to the gym so your workout can be varied and interesting rather than the gruelling tedium of endless crunches. Here's to flatter stomachs!.