1. Stretching before beginning an exercise prevents injuries. It helps the muscles "warm-up" and prepare before divulging into more intense exercises. It helps prevent "pulled muscles". It allows a longer range of motion. For instance, if you are going to do a strong punch without stretching, you will 'shock' your relaxed muscles into motion, thus it will cause pain and soreness. To prevent these from happening, begin with by gently pumping your arms, or by extending your arms overhead or below. You may also do leg extensions, either on the ground or elevated. For elevated leg stretches, it must not be immediate, but gradual and slow.
The higher the leg stretch is, the more the muscles are pulled, so one has to do it slowly. When stretching, don't bounce. Bouncing can cause small tears (micro tears) in the muscles which can cause scar tissues. These scar tissues can make movement painful and future stretching more painful and difficult. If you feel that the stretch is becoming more painful, then it means that you have gone too far. Focus on a more comfortable, pain-free stretch. Make sure to stretch both sides, too. It extends your range of motion more that way. Plus, movement doesn't just go one direction, does it?
2. Stretching improves flexibility. When you constantly stretch, you are also making yourself more flexible, thus activities that require flexibility, such dancing and kicks, short sprints and dashes, even basic tasks such as lifting and tying your shoe, can become easier. Flexibility also wanes s people ages, so it's best to regularly stretch so that you can maintain your flexibility.
3. Stretching promotes better breathing and respiratory (or oxygen) flow. Stretching allows oxygen to flow better through your body and it also helps better blood circulation. Body pains and sores usually root from increased tightness and tension from the lack of oxygen that flows to the different parts of your body. Stretching allows the oxygen to move freely and move better.
4. Stretching reduces stress and improves posture. Stress causes the muscles to tighten and knot, thus it can cause strain and back pains. Tension causes negative effects on your body. Muscles harden and slow down the flow of the oxygen (carried by the blood) to the brain which muddles thinking. Stretching brings back the oxygen flow and regulates it, re-oxygenating the brain and also the heart. Aside from contributing greatly to the circulation or blood flow, stretching also releases endorphins or the feel-good hormones in the body which can improve your mood and make you feel good. Stretching also greatly improves posture as it prevents the muscles from getting too tight, which causes slouching and rigidness of the body. When you have good posture, circulation flows better and you can look good and feel good throughout the day.
5. Stretch after exercising. Lactic acid builds up in your muscles while you exercise which leads to fatigue and soreness. This can be remedied by "cooling down" exercises or post-exercise stretching. Post-exercise stretching can help in workout recovery, decreases muscle soreness that comes after the workout and ensures that your muscles and tendons are in good working order. If you stretch after exercising, you are conditioning your muscles, and, in a way, you are relaxing your muscles after a vigorous regimen. Its goal is to return your muscles to the pre-exercise stage. It's like telling your muscles that the hard part of the workout is done. This part of the exercise is called the "cool down" and usually consists of light exercises such as brisk walking, calf stretching and static stretching. Aside from relaxing your muscles, cool down exercise are also meant to re-oxygenate your heart, since you have used too much oxygen working out.
This means allowing steady breathing and the muscles push the oxygen back to the heart.
Stretching, although takes minimal time in the whole workout or exercises, is still a very important part of the activity and should not be taken lightly. How sore you can get or how good you feel after a workout depends on how properly and how effectively you have stretched.
source : 5 Reasons Why You Should Stretch
