I think that everything you do helps you to write if you're a writer. Adversity and success both contribute largely to making you what you are. If you don't experience either one of those, you're being deprived of something.
Don't confuse hypothesis and theory. The former is a possible explanation; the latter, the correct one. The establishment of theory is the very purpose of science.
Many models do yoga, but I find it boring. I'd rather be outdoors having fun.