You no longer need to explain to anyone THAT exercise is healthy. The how and what is a bit more demanding.
For some, it may not be so obvious why you should work on your own mobility in addition to strength and endurance. Flexibility is the ability of one or more joints to move freely and painlessly through the natural ROM (range of motion). A joint's ROM varies from person to person, but a minimal ROM is necessary to ensure joint health and an individual's overall well-being. In other words: If you move your joints rarely, incorrectly, or insufficiently, you lose ROM in the corresponding joint. The joint and surrounding tissues are damaged by this lack of movement, immobile muscles tire more quickly and cause the opposite muscles to work harder, abnormal stress occurs in the connective tissue, tendons, and ligaments, and an overall feeling of tightness and stiffness. Immobile muscles also take longer to recover from soreness after strenuous activity.
Aside from the health disadvantages of insufficient flexibility, mobility can reduce the risk of accidents in sports that have a high intensity of SSCs (stretch-shortening cycles), such as soccer, and serve to increase athletic performance, for example by improving neuromuscular balance.
In some cases, stretching helps to relieve back pain, improve posture, increase movement efficiency, lead to inner and outer relaxation, and last but not least, mobility training can be a lot of fun.
Flexibility alone does not keep you healthy, just as little as pure strength or endurance training can guarantee this. If you neglect your mobility, you have to reckon with a reduced quality of life as well as reduced physical performance over time. Targeted stretching in the cool-down phase of a workout contributes a great deal to maintaining healthy joints. Yoga has also proven to be extremely effective in significantly increasing flexibility and body balance. In yoga, different movements are brought into harmony with the breath, making it a unique and holistic challenge for the body.
For more information about flexibility for health: