Sit ups are a very a good way to build and to develop your abdominal muscles, and the good thing in this exercise that you don’t even need any special equipment like other types of exercises.
The basic form
1- Start by laying down on your back on a flat and a hard surface, with your knees bent at 90 degrees angle and your feet flat on the ground like the following figure.
2- Put your fingers on the back of your ears, now you have to bend your elbows in a position pointing out at your sides.
notice that some people try to do some trick or mistaken positions by placing their hand and fingers around their neck, and this position will lead them to use their arms muscles and pull their self from the neck to perform the exercise.
But you also can put your hand over the chess in a crossed form if that suitable for you, like the figure:
3- Left up your torso from the ground toward your thighs as possible, you have to do that in a smooth way and avoid doing sudden movement as it will harm you and your muscles, you have to keep your motion steady while keeping your feet flat on the floor.
when you finish lifting up your torso from the ground, your lower back should be off the floor.
4- The next step is the inverse of the last one, now you have to go back to your starting position and to you have to keep the motion steady and smooth as possible as you can. and this is very important and you have to take seriously, some people develop lower back pain and even vertebral disc prolapse by doing this exercise in a wrong way, so please keep your self calm and try to concentrate and to breath normally while doing it, and never hold your breath while trying to force yourself doing that exercise.
5- Now you have to repeat that exercise on 3 sets of 15-20 repetitions.
Note: you can give your self 1 minute or 2 between each set, and never force yourself in adding more repetition without taking your time to rest until your muscles get more stronger.
1- Weighted sit ups
You can do that by holding a dumbbell or barbell weight against your chest and crossing your arms over it, or simply holding it by your hands.
never do that exercise if you are a beginner, this type of variation is for more advanced trainers.
you have to start with some light weight and then progress to more heavy ones as a gradual process.
2- Twisted sit ups
To perform this types of sit ups, the starting position is just the same the regular sit up, but when you left your torso from ground you have to to twist and to try to touch your left knee with your right elbow, then to go back to the starting position.
the next repetition have to be the opposite of the previous one, now you have to touch your right knee with the right elbow.