Adaptations to resistance training (Connective tissue part 2)

    In part 1 of connective tissue adaptions, we discussed how bones adapt to anaerobic training. This post will focus more on the adaptations of ligaments, tendons and cartilage. A little background about connective tissue before going into the adaptations. Ligaments and tendons attach bone to muscle causing bones to move. The stronger these connective tissues are the more force you can move with. Cartilage acts as a shock absorber with bones and joints. Cartilage also acts as an aid to reduce friction from bones rubbing against each other. Connective tissue has poor vascularity meaning nutrients are limited causing a longer period of time to heal. I am sure you or someone you know has experienced an injury to connective tissue either macro trauma (complete tear) or microtrauma (tendonitis) that took a while for that injury to heal up. I experienced tendonitis's in my patella tendon a few summers ago and it took all summer for that to heal up to begin running again. Even world class athletes need at least a year to rehab connective tissue tears. Cartilage on the other hand has no blood supply and relies on diffusion of oxygen from synovial fluid around the tissue.  

    Connective tissues are primary made up of collagen (Tendons also have elastin to maintain flexibility). Cartilage Type 1 collagen makes up bones, tendons and ligaments while Type 2 make up cartilage. Connective tissue responds well to mechanical loading. Crossing that strain threshold (not too much as that causes injuries). Continued progressive overload (resistance training) is one way to apply mechanical loading, another way is through sprinting and plyometric movements. You may have seen fighters in movies or in real life punching or kicking solid material over and over. This is an example outside of the weightroom that causes adaptations. These movements cause strain within the tissue signaling adaptations to take place. Additionally, moving the tissue through full range of motion will cause adaptations to connective tissue.

    Three ways that connective tissue adapt are in the junction areas between the connective tissue and the bone. Within the body of the connective tissue, and in the network of fascia with skeletal muscle. Network of fasica refers to the deep makeup of muscle tissue of the endomysium, perimysium and epimysium.    

Cross-Section of Skeletal Muscle Tissue

Cross-Section of Collagen fiber

     

    As you can see the cross-section of a collagen fibers looks very similar to a skeletal muscle fiber and adapts very similarly. Collagen adaptations can increase in fibril diameter causing thicker collagen tissue. A greater number of covalent cross-links within hypertrophied fiber causing a stronger connection between connective tissue and bones. Another adaptation is the number of collagens fibrils creating denser tissue along with the number of collagens the packing density increases as well. 

    Continued anaerobic training (resistance/sprints/plyometrics) will cause connective tissue adaptations. Outside of the weight room supplements are an option. Collagen supplements can be expensive. A better option (and cheaper) would be Vitamin C. Vitamin C plays a significant role in collagen formation and provides additional value to the body that pure collagen supplements do not provide.