There are many ways to get fit and healthy. Movement is what’s key.
Weights are great for a limited range of fixed movements and they are great for putting a great load on quickly, which allows you to build strength and muscle. However, there are certain ranges in activities such as yoga, tai chi chuan and Thai boxing that you simply couldn’t get in to with weights in your hands or strapped to your legs as the body has a fluidity of movements and should move without rigidity. Instead of using force it’s about decelerating the body.
A lot of weight training involves acceleration on the push and unless you train a lot on the eccentric, a lot of people that do weights are not very good at decelerating the body rather than accelerating it; which is another form of control, alignment and strength.
Also there are other movements that you can learn to use your whole body in creating. For example, a punch comes from the feet, to the hips, to the core and through the fist. It’s not in a fixed position as you would be in a bench press, and it wouldn’t be repetitive as the opponent would be moving.
Yes, weight training does build joints and ligament but then so does yoga and tai chi in completely different ways and in what feels like more intricate areas, for me, as I’m more used to weights. A massive factor for yoga and martial arts is the balance of the foot and how you balance in different positions with your feet.
I’m not purely promoting tai chi and yoga as I absolutely love weight training but I also love movement. My point is to mix up static and dynamic styles of training, and it is important not to just mix it up for the sake of mixing it up. Instead, find a goal, find your strengths and weaknesses and give a holistic, whole view approach to your training that gets you the fittest and healthiest you can be.