IB Sports, exercise and health science B.1.2.3 Training Adaptations of Connective Tissues Notes

Load Drives Adaptation: The Underlying Principle

1. Mechanical load creates microscopic damage in connective tissue, the body senses this damage and lays down new collagen, mineral, or matrix in response, and after enough load-and-recovery cycles the tissue becomes stronger.
2. Without enough rest, sleep, and nutrition, damage outpaces repair and the tissue weakens, producing an overuse injury such as a stress fracture, tendinopathy, or cartilage degeneration.

The Role of Training in Connective Tissue Adaptations

Regular training leads to various adaptations in connective tissue, improving stability and movement efficiency.

1. Increased Collagen Production

1. Collagen is the primary structural protein in connective tissues.
2. Training increases fibroblast activity, which enhances collagen synthesis.
3. Stronger collagen fibers improve tissue tensile strength, reducing injury risk.

Bone Becomes Denser and Stronger

1. Weight-bearing activity stimulates bone cells to deposit mineral salts and collagen, which raises bone mineral density (BMD) and increases tensile strength.
2. Activities producing ground reaction forces and large muscle pulls, such as running, jumping, and lifting, drive the strongest bone adaptation.
3. Gymnasts, sprinters, and weightlifters typically have higher BMD than the general population, while cyclists and swimmers, whose sports involve little impact, often show BMD similar to or lower than sedentary controls.
4. Bone laid down during adolescence sets a peak that is hard to recover later in life, which is why weight-bearing activity in youth has long-term consequences for skeletal health.
5. Disuse reverses adaptation: bed rest, immobilisation in a cast, and spaceflight all reduce loading and produce rapid loss of bone mineral density, so return to activity after a long break must be progressive.

2. Tendon Adaptations

1. Increased collagen density makes tendons stiffer and more resilient.