1. Get on all fours, face the ground, support your body with elbows and toes, and keep your body straight. Hold this position for 20 seconds or as long as possible.

2. Lie flat on the ground with your hands akimbo. Lift your legs up and make a 90-degree angle with your upper body. Move your hips up with the strength of your abdomen, and then fall back. This action is repeated in 3 groups, each group 10- 15 times.

3. Upward inclined sit-ups. Lie flat on the floor and lift your legs at an angle of about 60 degrees. Put your hands behind your head, lift your upper body, touch your right knee with your left elbow, and then change your right hand. Repeat 3 groups with 25-30 in each group.

4. Lie flat on the ground with your hands akimbo. Lift your legs up and make a 90-degree angle with your upper body. Move your hips up with the strength of your abdomen, and then fall back. This action is repeated in 3 groups, each group 10- 15 times.