This microtrauma will cause the tissue to swell (edema) with an influx of inflammatory cells, and in the healing phase, there can be development of fibrous or scar tissue. During the initial inflammatory phase of this process the muscle responds with a reflex spasm which is the tightness or knot you can feel.
Stretching or massage (where someone else is stretching the muscle in question for you) can help to relax this muscle spasm and minimize edema with subsequent fibrous tissue formation. And there is some evidence that a muscle that has been fully lengthened (stretched) before activity will contract more forcefully and improve performance.
It is important to stretch only after the muscle to be stretched has been actively warmed up - either with 5 or 10 minutes of exercise or in the post exercise period. There is scientific evidence that this will increase tissue elasticity and ductility, and reduce the frequency of injuries directly related to the stretching itself. Does stretching done after the warmup period decrease the incidence of injury from the subsequent activity? That is unproven at this point, but common sense would suggest that if the muscle edema and spasm are minimized, there should be less stress on the muscle fibers and thus less additional injury.
For cyclists, the most common muscles requiring post exercise stretching or massage are the hamstrings, quadriceps, and shoulder muscles. As an inflamed muscle, or one in spasm, is uncomfortable to pressure, it is easy for you to identify your own areas of overuse.
When massaging a muscle, two approaches can be used. First is to apply pressure on the area of discomfort (the palpable knot) with the muscle in a neutral, relaxed position. The pressure is then moved along the direction of the muscle fibers (remember to massage in the direction of the muscle fibers - the direction of pull of the muscle) to counteract the spasm and "work out" the pain. Over the last few years, there has been increased interest in "active" strecting or massage which means that steady pressure is maintained on the tender area or muscle, and the extremity is actively put through it's range of motion, contracting and moving the muscle beneath the point of pressure. The theory being that this involves the nerve/muscle unit and may retrain the entire motor unit to sustain a decrease in spasm after the massage session has been completed.
What can you do to maximize the benefits of a stretching program?