Yang deficiency belongs to the category of TCM health preservation, and muscle training belongs to the category of western human sports science. Just like Newton's classical mechanics and quantum mechanics, or just like physics and chemistry, both of them have their own scientific systems, and basically can't be mixed together to talk about anything. If you are yang deficiency, then you are using Chinese medicine science to find ways to improve yang deficiency. If human sports science thinks that your waist muscle quality is declining, then improve your muscle quality through strength training.

Of course, I personally think that the same thing, such as western medicine and Chinese medicine, will eventually have a reasonable explanation, but at present, the level of human understanding of Chinese and Western medicine is still very low, and many things are still incomprehensible, not to mention integration.