So basically I am looking for something I might have around the house or can go buy that is reasonably priced that will hold my feet when I am doing full situps (not crunches) I used to have pair of adjustable dumbbells with large plastic coated plates that was the perfect height for my feet to slip under, but I don’t have them anymore. I looked at buying new adjustable dumbbells but the plates that go on the sides are smaller so my feet won’t fit under them and they were extremely expensive.
I slip my toes under the sofa.
::grumble, grumble:: White SIFL beat me to it. Sofas are perfect for shoving your toes under.
Is this a serious question?
Feet under a piece of furniture.
Toes under the couch.
My last couch didn’t have enough room for me to put my toes under it, so I put a ratchet strap around it and put my toes under that. (Sometimes it’s good to be a guy living alone! 
The SO made me get rid of that couch.)
I know you werent asking about this but can i ask you why you are doing situps? What are your target muscles you want to build?
Aren’t situps considered bad now because they are hard on your back?
Have you looked at some other exercises, depending on what you are working.
I just put my feet out further or even just keep your legs straight.
I do the opposite and bend my knees placing my feet flat on the floor. When there isn’t a piece of furniture handy.
grumblegrumble*, **Spiderman **and White SIFL both beat me to it!
Would one get a better workout if you didn’t put your feet under anything while doing crunches?
A friend of mine uses a very large dog instead of a sofa.
If you happen to have no sofa, or an inflatable one, you could also invert them–sit in a chair. extend your legs, draw your legs up to your chest, repeat. Not the same set of muscles, but you’ll feel it.
The one that I hated was the rollup… Lie on your back with your hands clasped in front of your chest. Roll up on your right elbow and touch your left elbow to your right knee. Roll back down, then roll up to the left.
I don’t really understand the question. What happens if your feet aren’t under anything? For me, the situp proceeds normally. Does it work differently for other people, or is it safer to have your feet anchored, or what?
Depends on your weight distribution. People who carry their weight lower can do situps fine without any ballast. Others have the ballast above the water line, and it’s a different story.
Ambivalid is on the right track…why are you doing situps?
We did them that way in gym years ago = hands on your neck and just do them.
This is the way sit-ups should be done properly, as I’ve always understood. Knees bent, feet flat on the floor. Hands either behind your head, or arms folded across your chest.
Legs straight is hard on the lower back.
make a loop,attached to weight plates, using a strap or belt to put your feet through
Yes, if you squeeze together your legs perfectly straight and flat, you can do sit-ups without someone holding your feet. I tried it just now, and my feet would rise about an inch or 2 off the floor. So I’m guessing maybe a heavy pair of boots would easily provide enough torque to keep the feet down. Years ago I saw the world-record-holder demonstrate this technique, when the record was a mere 25,555.
For myself, however, I built this contraption out of some 2x4s that looks like a bedframe kinda with 2 parallel poles at one end that you would tuck your knees over the first, and your feet under the second. Works great.
Now here I would’ve expected Spiderman to just stick his feet to the ceiling, then bend to touch his head to his thighs – maybe adding a bit of a challenge by holding a bus in his (sticky) hands, too.
That would build the abs for taking the sissy punches from common street thugs.
[Shots to the gut from super-villains are a whole different category of ouch.]
–G!
I do tons of situps for tennis. Never had a problem with someone not holding my feet though.