A strong core is essential for maintaining proper posture, stability, and overall physical strength. Here are 13 core strengthening exercises that you should know to help build a solid and stable core:

1. Plank:
– Start in a push-up position with your arms straight and hands directly under your shoulders.
– Engage your core and keep your body in a straight line from head to heels.
– Hold the position for as long as you can while maintaining proper form.

2. Bicycle Crunches:
– Lie on your back with your hands behind your head and legs lifted off the ground.
– Bring one knee towards your chest while simultaneously twisting your torso to bring the opposite elbow towards the knee.
– Switch sides, alternating in a pedaling motion.

3. Russian Twists:
– Sit on the floor with your knees bent and feet flat on the ground.
– Lean back slightly and lift your feet off the ground, balancing on your sit bones.
– Hold your hands together in front of your chest and twist your torso to the right, then to the left, without touching the ground.

4. Dead Bug:
– Lie on your back with your arms extended towards the ceiling and knees bent at a 90-degree angle.
– Lower your right arm and left leg towards the floor while keeping your back pressed against the ground.
– Return to the starting position and repeat on the opposite side.

5. Superman:
– Lie face down with your arms extended in front of you and legs straight.
– Lift your arms, chest, and legs off the ground simultaneously, squeezing your glutes and lower back muscles.
– Hold the position briefly before lowering back down.

6. Leg Raises:
– Lie on your back with your hands under your lower back for support.
– Lift your legs off the ground, keeping them straight, and lower them back down slowly without touching the floor.

7. Side Plank:
– Lie on your side with your elbow directly under your shoulder and legs stacked on top of each other.
– Lift your hips off the ground, creating a straight line from head to heels.
– Hold the position for as long as you can and then switch to the other side.

8. Mountain Climbers:
– Start in a plank position with your hands directly under your shoulders.
– Bring one knee towards your chest and then quickly switch legs in a running motion while keeping your core engaged.

9. Bird-Dog:
– Start on your hands and knees with your hands directly under your shoulders and knees under your hips.
– Extend your right arm and left leg simultaneously, reaching them out straight.
– Return to the starting position and repeat on the other side.

10. Lying Leg Twist:
– Lie on your back with your arms stretched out to the sides and legs lifted off the ground.
– Lower your legs to one side, keeping them straight, until they are a few inches off the ground.
– Lift your legs back to the center and then lower them to the other side.

11. Boat Pose:
– Sit on the ground with your knees bent and feet flat on the floor.
– Lean back slightly and lift your feet off the ground, balancing on your sit bones.
– Extend your arms straight out in front of you, parallel to the ground.

12. Scissor Kicks:
– Lie on your back with your hands under your lower back for support.
– Lift both legs a few inches off the ground and cross one leg over the other in a scissor-like motion.

13. Reverse Crunches:
– Lie on your back with your hands by your sides and legs lifted towards the ceiling.
– Curl your hips off the ground and towards your chest, lifting your glutes off the floor.
– Lower your hips back down to complete one repetition.

Perform these core strengthening exercises regularly, focusing on proper form and controlled movements. Gradually increase the intensity and duration of each exercise to challenge your core muscles and improve strength and stability. Remember to consult with a healthcare professional or fitness expert before starting a new exercise routine, especially if you have any pre-existing health conditions or injuries.