The practicing of a martial art is a unique process. Many would liken it to education, or a manufacturing process. I would argue that martial arts are a complete change process that is greater than both.
A manufacturing process takes raw materials, and uses machinery or tools to change the materials into something else.
Education is a process for the giving and receiving of systematic instruction.
However, a martial art educates the raw materials (people) on how to change themselves. The teacher shows the students what to do. Then, through repetition of actions, the students refine their strength, movement and reflexes. They become more healthy, flexible, fast and strong. This improvement in health and body mechanics produces a change in the students' consciousness (i.e. if the reflexes are better and the body moves faster, the mind becomes sharper). This improved consciousness then has an effect of making the body work better.
You can now see that a virtuous circle has been set up whereby the body improves the mind, and the mind improves the body. This process continues regardless of age, ability or gender. All that is required is to keep practicing.