For flexibility training, you must first consider your goal. Unlike the other Keys, your goal for flexibility is simply in one of two categories: to increase your flexibility or to maintain it.
Next, things start to get complicated by determining where in your body you want to focus each of those goals. There may be areas where you don’t need to increase your flexibility and others where you do.
For areas where you want to maintain the flexibility, you don’t actually need to do anything more than move that area through its full range of motion on a regular basis. In fact, using full range on many resistance training exercises can often be enough to maintain the flexibility for those muscles.
Increasing flexibility, obviously, will take a little more of a concerted effort. And while there are many different methods, one of the best and safest is static passive stretching performed after the muscles have been working and are warmed with activity and blood flow.
Static means that the stretch is held and not moving like other types of stretching. Passive means that someone or something is performing the stretch, allowing the muscles and the individual that is being stretched to relax.
To get the benefit from static passive stretching: First, get moving using those muscles. Second, relax and allow the body part to be moved into a position where you can feel a stretch. Third, stay at this position until you feel the stretch sensation ease. Then to increase flexibility you can move into a position of greater stretch. Gentle and slow you can progressively increase your flexibility using this method.
As always, let me know how I can help.