Strength
Strength is the ability to produce maximal force via muscular contraction.
Strength training is the most important type of exercise we can perform. It can even be argued that strength training is the closest thing to the Fountain of Youth we have discovered as a human race.
While other forms of exercise like walking, running, swimming, biking, and running are great for our cardiovascular and general health, they fail to improve movement quality or build muscle mass because the loads placed on the body, while highly repetitive, are too low to incur strength adaptation. This is why runners commonly experience soft tissue injuries like IT Band Syndrome and Achilles Tendinopathy. Strength is its own discipline of training, and it should never be neglected no matter your lifestyle.
Whether you are an ambitious athlete or simply someone looking for a greater quality of life, strength and conditioning holds much of the answers we are all looking for. There is a reason why the primary rehabilitative modality of Physical Therapy is strength training. Strength training is proven to improve not only muscle mass but also connective tissue (tendons and ligaments), bone density, and overall health.