My question is: How can I do the equivalent of sit-ups or stomach crunches without getting down on the floor? Preferably free ways, please. I have no money. Some people have told me about this ab swing thing that you sit in to do crunches, but according to the web site, it will not hold my weight.
So how can I exercise my stomach without getting on the floor? Can I suck my stomach in and hold it for a while and release? Will that be effective? Any other parts of my body I can exercise without making my knees pop out of place? I really want to do this, but it's very hard for me to find an exercise I can do. :(