Yes doing a lot of sports definitely has an effect on your health. I remember when I was doing my A-level exams I had to give a lot my sport up and I used to get out of breath walking up stairs or if I had to walk fast if I was late. Now I’m back to doing a lot of sport for some reason it makes me feel a lot happier and its a good stress reliever.
With regards to joints some sports with extreme ranges of motion or high impact are thought to be linked with some joint problems but I think it also needs to be combined with an already existing problem. I have bad joints (which I can thank my Dad for) and if I play a lot of netball my ankles often ache but usually wearing supports sorts it out. So overall I think doing a lot of sport is generally a lot better for your health than it is bad.