Performing the: A Step-by-Step Tutorial 3/4 Sit-up
Place your hands behind your head, or crossed on your chest, ensuring not to strain your neck when you perform the sit-up.
Engage your abdominal muscles and lift your upper body off the ground towards your knees, but stop at about a 3/4 position, meaning you don't go all the way up to your knees.
Hold this position for a second, focusing on the tension in your abdominal muscles.
Lower your body back down to the starting position in a controlled manner and repeat the exercise for your desired number of repetitions.