They are made of muscle and therefore are not able to be replaced as with skin and connective tissue and you can do your exercises more effectively.
They can stretch more when you move, because they have more space to expand in. They help keep your spine straight in a straight back position. They provide a smooth surface for the muscle fibers to work on. They are a great source of strength and can help protect your spine in a fall.
BASIC EXERCISE HABITS - What to do to prevent developing a saggy back 1. Kneel in front of a mirror. 2. Straighten the upper back and the chest. 3. Lift the chest. 4. Lift your legs. 5. Lift your feet from the floor. 6. Lift your chest up towards the ceiling (don’t lift it higher than your head). 7. Lift your shoulders up and back. 8. Lift your butt up towards the ceiling. 9. Lift your head to chin height. 10. Lift your arms up and out to the side. 11. Lift your heels up. 12. Lift your knees up and back.
13. Lift your arms up and out to the side. 14. Lift your legs up and back. 15. Lift your hips up towards the ceiling. 16. Lift your head up towards the ceiling. 17. Lift your entire body up to the ceiling. 18. Lift your neck up and back. 19. Lift your arms back and forth. 20. Lift your knees back and forth. 21. Lift your legs back and forth. 22. Lift your butt back and forth. 23. Straighten the legs. 24. Straighten the arms. 25. Lift your butt up towards the ceiling.