How is a high impact exercise bad for joints?

Answer 1

High impact exercise is bad for joints for the following reasons:

1. HIE (High Impact Exercise) makes bones denser, not stronger. Over-dense bones become less flexible, more brittle and more likely to fracture. This happens because HIE increases bone microfractures which get filled with new bone, making them over-dense. There is ample research to show this. We want strong bones for tensile strength, not over-dense bones that become brittle and inflexible.

2. HIE wears out the cartilage that normally serves as a shock-absorbing cushion between bones. Its breakdown results in bones rubbing directly against one another during movement. Such friction causes the bone to thicken so that spurs (bony growths) may develop between joints. Stiffness, pain and loss of movement may occur as the joint lining becomes inflamed by cartilage breakdown and spur growth.

3. HIE erodes osteoblasts (cells that maintain and re-new bone). This happens because HIE greatly increases bone microfractures. In the process of filling the microfractures with new bone about 70% of osteoblast cells involved in making the new bone will perish. As the body's potential for producing osteoblasts is limited, you always want to minimize their erosion. The risk of osteoporosis and joint problems is increased when osteoblasts cannot make enough new bone to keep up with the rate of decomposition of old bone that is always melting away.