If you go on medication as a younger person you may find you can regain your strength and coordination if you can get tailored advice (and even just using your own common sense)
I am seventy but since taking sinemet (standard med. for 70 yr olds like I was) for 18 months I have regained the fitness I had two or three years before.
I have taken up Nordic Walking which can be done at any level. It exercises the whole body and is good for your spine and for balance. Also yoga very good for stretching the muscles. Use it or lose it applies even more so to PWP - my personal pet theory is that your brain is constantly relearning to do things with less dopamine before the symptoms show up until there comes a point when it can't . I thought this before I was dx with PD but before then I harboured the idea that I might have a benign tumour pressing on part of my brain. I never told the doctor because the symptoms were something and nothing kind of things like a jerk of the hand as I applied lipstick. Even when I first reported my hand tremor there was little interest.