If you’re one of the many, many people who prefer not to do sit ups but you want to increase your core strength and stability, try the seated leg lift.
To do this exercise, sit on the ground with your feet straight out in front of you and your upper body at a right angle from your legs. Place your hands on either side of your body to stay balanced.
Engage your core, then lift your right leg off the ground as high as you can, keeping your leg straight. Lower it slowly back to the ground. Repeat with your left leg.
Do this exercise 12 times on each side, alternating from one side to the other. Once you’ve gained more strength, rest for one minute after the first set and do another one.
For best results with the seated leg lift, make sure you’re breathing during the exercise and raising and lowering your legs off the ground slowly so you aren’t depending on momentum or gravity to do the work for you.