Flexibility is the range of motion possible at joints throughout the body. Neither too much nor too little seems best for joint health.
Flexibility depends on many factors:
- Joint structure.
- Muscle insertions and size.
- Connective tissue elasticity.
- Psychological factors, as range of motion is much greater with unconscious trainees.
- Gender, age, genetics, injuries, and so on.
Some seem to show great flexibility but instead show a unique joint structure. Those that can hyperextend the forearm at the elbow have a deep olecranon fossae or small olecranon processes as opposed to great flexibility. Due to all of the differences among people, avoid comparing your flexibility with others. This is good advice for fitness in general.
Flexibility is specific to a joint as there exists no indirect effect for it. Connective tissue inside and surrounding the muscles of a joint gives the main physical restriction for a stretch. Stretching allows you to loosen this tissue in the long run.
Flexibility, unlike other fitness components such as strength or endurance, has an ideal range. Although great flexibility helps athletes perform unusual movements, it can increase the risk of injury. The risk of injury appears greatest when flexibility is either very high or very low.
If you lose your balance and fall, the stiffness in your muscles helps to protect the joints from bearing the stress. Too much flexibility prevents this stiffness and has the joints absorb the force. A muscle strain heals more easily than a dislocated shoulder or knee.
Too little flexibility will harm you too. In our sedentary world, muscles shorten due to too much sitting and a lack of activity to keep us limber. Tight hip flexors and hamstrings can prevent good posture. A tight chest can slump the shoulders. Stretching can combat these issues.
Some flexibility also may give athletic benefits for certain events. When approaching unusual levels though, as required for some athletes, development may be necessary for their sports but still up the risk of injury.
I consider too much flexibility when it exposes your joints to harm. During motions that test your flexibility, you will know if has grown excessive if you feel it in the joints instead of the muscles. Many stretches smash the endpoints of the bones against the soft muscle tissue which can harm you.
Much of the support for stretching is anecdotal but it will certainly help someone that fails to have enough flexibility to use good form. The benefits of stretching seem to be achieved through a warm-up though.
It may reduce the likelihood for muscle strains and cramping. It can further assist a warm-up. Connective tissue loosens which allows more freedom of movement. It improves blood flow and may aid the nervous system by improving the mind-muscle connection. It may blunt reflexes that hamper maximum muscle contractions. Some trainees report that it reduces soreness after the workout.
Some experts mention studies showing muscle cell growth from extreme stretching. Unfortunately this growth may just compensate for the new muscle length and have no real value. This also remains to be demonstrated beyond animal studies, and the danger from extreme stretching is very high.
Always complete a warm-up before stretching.
Your muscles act like puddy. If cold, they act stiffly and stretching may harm the muscle. If warm, they become pliable and easier to stretch. Many will notice their stretches extend even further if completed after a workout and not just after a warm-up. Therefore post-workout may be the ideal time to increase flexibility.
Vigorous stretching before a workout may reduce strength and power. This occurs because a lot of tension can develop while stretching, which fatigues the muscles and can lessen the pre-stretch. This only presents a problem though if conducted too aggressively. Too aggressively means holding the stretches to the point of feeling exhausted afterward. You will avoid this if you follow my guidelines for a complete stretching routine.
Ballistic stretching relies on bouncing into a stretch. This involves quick, repetitive motions that last for a short time. This causes a short-term change in the tissue but then you just return to the original length after a short time. It carries more of a risk for injury due to the force spikes that test your limits and give you little time to react if the stretch goes too far. It can also cause muscle spindles, sensors in the muscles that detect excessive lengths, to send signals to the muscle which prevents further stretching. This style may have rare sport-specific uses but still works least effectively.
Static stretching relies on holding a stretched position. This involves less energy, more safety, and allows the muscles to relax. This relaxation prevents reflexes from limiting the stretch. Long-lasting changes can occur as this deforms the tissue.
PNF stretching alternates periods of relaxation and contraction. This achieves an even greater range of motion than static stretching. This works very well for tight muscles that affect most trainees such as the hamstrings.
Stretching for Flexibility
I suggest against stretching unless needed for your sport. A warm-up alone if sufficient.