Updated: Oct 3, 2018
To understand just how relevant this law is It's vital to know precisely what the ligaments and tendons do why we need them and then how to strengthen them.
Let's start with ligaments; a ligament is the fibrous piece of connective tissue that connects bones to other bones yup if you didn't have them you'd have a hard time standing up they join up all the bones to give your skeleton its structure. Tendons while being very similar to ligaments attach your muscles to your bones, tendons allow you musculature system to act upon your joints to cause limbs to flex and extend, it's our Central nervous system that then orchestrates the movement like a perfect symphony to allow running, jumping, throwing etc.
Tendons can store and return kinetic energy. The elastic ability of the tendons allows them to be capable of returning up to 93% of the elastic energy applied to them in their recoil. The Stronger the tendon is, the greater is its capability to store elastic energy.
Ligaments and Tendons are trainable, and their material and structural properties change as a result of training, increasing in thickness, strength and stiffness.
The problem we have is that the strength and force generating capabilities of muscle increases at a faster rate than the ligaments and tendons ( one or the reasons I believe why so many people who use steroids rupture tendons as their muscles adaption is even quicker than that or a natural athlete). One of the leading causes of injury to the tendons and ligaments comes from a lack of long-term vision from the coach or athlete. If progress is accelerated too quickly or there isn't enough variation in intensity in the program, then you may not be providing the ligaments and tendons the extra time needed for repair and adaption.
The primary stimulus for the growth of tendons and ligaments is the mechanical forces created during exercises. The degree of tissue adaption appears to be proportional to the intensity of the loading. To ensure continual adaption stimuli must exceed current thresholds to induce further adaptions.
It's important at this stage to remind everyone that tendons and ligaments do not adapt as fast as muscles so blocks of training dedicated to GPP (General Physical Preparation) otherwise known as Anatomical Adaptation must be included as part of a complete training program. This Phase of training involves doing a very high volume of general work with a relatively low intensity 30-50% of 1rm its purpose isn't to increase strength but to prepare the body for the strength building phases that come later in the program. The larger the foundation, the higher you can build. It's also a time to ensure that all areas of the body are developed equally to avoid overuse when it comes to specificity. This phase of training lasts 4 to 8 weeks, and I recommend at least 2/3 blocks of your yearly cycle are formed of these AA/GPP blocks to ensure full development of the tendons and ligaments as well as ensuring musculature balance is achieved.
For those who do not possess a strength training background, I recommend that these blocks last longer 8-12 weeks and form a more substantial portion of the yearly training cycle.
It's also important to take regular microcycles of reduced loading during strength and power blocks to allow the connective tissue to recover and adapt to the training stresses placed upon it. As a general rule, the greater the magnitude and duration of the loading the greater the time needed for fatigue dissipate and performance improve. At Devanney Strength we use a 3:1 ration of loading to restoration. This means that for every three weeks of loading we have one-week of restoration. The restoration week isn't a rest week its an active recovery we spend more time stretching and doing soft tissue work as well as reducing the volume and intensity of our training.
Law 3 - Core Strength https://www.devanneystrength.com/articles/law-3-core-strength