Length and Strength:
Your muscles needs to be in proper Length to gain Strength completely in a Muscle. That is why it’s not a Good idea to start the strengthening right away without stretching/lengthening the muscle. If you wonder how the sports people are able to generate force every time. They make sure that all the muscles have the length first before the work on the strength. When your muscle does not have the Length it won’t gain the strength totally which makes some of your muscle fibers inactive. So over a period of time the Active fibers begin to dominate the Dormant fibers which remains Inactive. This also would lead to shortening of the muscle more. Thus it’s important to lengthen the muscles.