Doing these sit-ups causes my muscles to tighten up like a boa constricter!
134379
Well, that's kind of what doing sit-ups is supposed to do :) Try doing crunches instead.  Lay on your back with your legs either resting on a bench or a bed, put your hands behind your head, and use your abs to pull your shoulder blades off the ground.  It'll work mainly your upper abs, so try to supplement by doing some bike work or knee tucks, flutter kicks, etc., for your lower abs.
18133
Focus on crunches which work the abdominals much better than sit-ups.  \n\nHere's a short list, but I would advise to seek the advice of a personal trainer for proper execution and intensity.\n\nhttp://preventdisease.com/fitness/Strength_Exercises_abdominals.html
662210
sit ups with legs bent at knees left elbow to right knee and right to left.\nAlso roll legs over to left and try to do sit up and then reverse it.\nDON'T DO ANY OF THESE UNTIL YOU CHECK WITH A QUALIFIED TRAINER FIRST I'm not one
26139
Try doing crunches from a sitting position, in a straight backed chair. You get the same results, with much less discomfort to your back. You just need to pull your knees up toward you and let them down slowly. It works wonders!
457734
You ae compressing your body a bit as gravity pushes your torso down...but the big reason is the same as folding a pillow...the material and padding bunches up at the bend, same as happens in your lap.
385119
to get tight "body" the only exercise seems logical is a combination of sit up and push ups...try suiting yourself to the number of times you can do..if you can do 50,make it 50...if you can do 100, make it 100..don't cut down on your food...eat like a human..do not OVEREAT...try doing as many session as possible in a day..then you'll have a tight body
235897
This helped me... After whatever workout you do, add this before you throw in your towel...\n3 sets of 20 reps of regular sit-ups\n3 sets/ 20 reps of right side sit-ups\n3 sets/ 20 reps of left side sit-ups\n3 sets/ 20 reps of lower ab sit-ups\n\nAll are done with your back to the floor so your not changing positions all the time. Side sit-ups are done with a twist... right elbow to left knee and vica-versa. For the lower abs (the most important to focus on) just lie with your back to the floor, legs stretched, and lift your feet maybe 5 inches off the ground while your legs are still extended
75091
Sit-ups are good.  Also try doing this sit-up variation—lay on your back, put your hands behind you head, bring you knees up to your chest.  Then stretch one leg out straight (lets say the right one), making sure that it does not touch the floor but remains parallel to it. Leave your left leg bent against your chest.  Take your right elbow across and touch your bent left knee.  Then bring your right leg back up to your chest, stretch out you left leg and take your right elbow across to touch your bent right knee.  This exercises most of the muscles in your chest and abdomen as well as the muscles in your back.
395306
ALL SIT-UPS ARE GONNA DO IS STRENGTHEN YOUR ABDOMINAL MUSCLES...YOU PROBABLY WANT TO BURN OFF THE FAT THATS IN FRONT OF YOUR ABS, do that with interval training and circuit training... sorry, caps was on !...
373502
Do more abdominal exercises.
372676
shitload of sit ups and crunches
174890
when i exercise i do bicycle crunches. my back is almost flat on the ground and im getting an ab workout.
213738
Do leg lifts while you're sitting.  Tighten up your abs, hold them for a few seconds, then release them and do it repeatedly.
443464
Abdominal Crunch\nThese are excellent for strengthening the abdominal muscles and reducing a protruding stomach. Lie on the floor. Hold your legs at a 90-degree angle with your lower legs parallel to the floor. (You can also place your legs over a bench or a piece of furniture.) With arms at your side (or on shoulders or behind ears as in the curl-ups), inhale slowly as you raise your shoulder off the floor, forcing your chest muscles toward your legs. Pull your hips upward, hold for a second, then exhale slowly and roll down to the starting position. Do up to twenty-five repetitions.
513883
Lots of sit-ups, make them a regular everyday thing and it will disappear, it can happen man ! so go make it happen! it will take a bit of effort though i won't lie.
73015
I don't know.  Curl-ups? (Sit ups?)
221400
You don't need to do full sit-ups. Do crunches instead and only go up to where you start to feel the pull of your abs then hold it there for a couple seconds. But make sure you are keeping your back and neck straight so that you don't injure yourself in the process.\n\nIf you HAVE to do full sit-ups make sure you are doing them correctly. Back and neck straight. You might want to consult a personal trainer to show you the proper technique.