How stretching works
Before explaining the inner-workings of stretching, one must understand how muscles function. Muscles are made up of small strands of tissue called fascicle, which themselves are composed of a whole bunch of other smaller components. Add to that connective tissues, fascial sheaths, lubricants, and a plethora of other things that will make even a biologist's head spin, and you get a fully functional muscle. Working out makes all those parts interact with one another.
When a person contracts a muscle, fascicle strands come into play. Depending on the poundage, a muscle will contract a different amount of fibers. Muscle strands can't vary how much they contract; they either contract or they don't, so in order to lift a heavy load, more fascicles have to constrict. That being said, as you increase the intensity of your workout, more muscle breakdown and fibers intertwine.
After an intensive workout, muscles need to repair themselves and fibers that are entangled impede the recovery process. When you stretch a muscle, tension in the fiber increases, aligning the disorganized tissue in the same line -- like when you pull on a wrinkled shirt. In addition, it keeps the blood flowing and tendons flexible.
Benefits of stretching
As aforementioned, stretching realigns muscle fibers. This speeds up the recovery process after a hard workout. When fibers are intertwined, scar tissue requires more time to heal. Serious bodybuilders know how important recovery can be. When a muscle takes too long to recuperate, an entire workout cycle can be interrupted, slowing down muscle gain.
Studies have shown that performing stretching exercises reduces the risk of injury and soreness. It also reduces soreness felt the next day by decreasing the build-up of lactic acid in muscles. Stretching can also prevent cramps; some muscles, like calves, have a tendency to cramp up more than others.
Furthermore, stretching attenuates the stretch reflex, the body's automatic defense mechanism to overextension. Holding a stretch for a prolonged period of time habituates the reflex so it reduces its signal. This helps muscles have a fuller range of motion -- quite useful in bodybuilding since a proper range of motion during reps increases a workout's effectiveness.
Types of stretches
Ballistic
Ballistic stretching was prevalent in the past, but is seldom used among most professionals today due to its unsafe nature. Such stretches use a person's own momentum to hyperextend a muscle beyond its normal limit. For example, when stretching a hamstring, a person would forcibly press down or bend over towards the knee in a jerking motion.
Static
Static stretching does not require a partner and is very safe and effective. To perform a static stretch, simply set yourself in position and use your own strength to get the desired tension. Once in place, hold the stretch in a comfortable yet firm pose.
Passive/Isometric
Passive and isometric stretching is quite possibly the best and most frequently used. To perform either one, you need outside assistance, like a towel, a partner or a wall to increase the range of movement. Not as dangerous as ballistic stretching and slightly more forceful than static stretches, this category is a must for some body parts, like calves.
How to stretch
Today, ballistic stretching is frowned upon, unless you are a gymnast or ballerina. You should never jerk a muscle beyond its limit. If it doesn't feel comfortable, don't do it.
Warming up before stretching is very important. A warm-up will increase elasticity and coordination; in other words, it will reduce the risk of having an injury while performing stretching excercises, which would be a shame since stretches are supposed to prevent injuries. Keep in mind that stretches are not warm-ups! A warm-up starts with joint rotations, then a little bit of cardio or aerobics -- about 5-10 minutes.
After the warm-up, stretches are usually performed before, during and after an exercise. They work best when held for up to 30 seconds. Instead of just sitting on a bench waiting for your next set, stretch; it will give you something to do.
Isolate muscles while you stretch. It's always better to work on one muscle at a time than a whole bunch of them at once. Isolating one muscle gives you more control.
Stretch it up
Stretching is an intrinsic part of working out; it helps prevent a lot of injuries. Keep doing it before, during and after each exercise, and you will likely never have a cramp or injury at the gym. And don't worry about looking like a dork, all pros do stretching excercises before workouts.
Important rules for stretching:
1) Never stretch cold muscles. The best time to stretch is after you walk. If you have problem areas they can be stretched prior to your walk, but only do this after you have warmed up.
2) Do not bounce. Go into a stretch slowly and hold gently. Stretch to the point of feeling a gentle pull, but never to the point of pain.
3) Hold each stretch for 30 to 40 seconds. If you have problems with a particular area stretch that area twice. (Hold for 30-40 seconds, release, then stretch again.)
There are so many stretches, it is impossible to cover them all. Be sure to stretch all the major muscle groups, and put extra focus on any areas you have trouble with. Find a few recommended stretches below:
