Given that you are ADD/ADHD, it might do more good to read up on diet and brain chemistry. I am all for better health but good brain health is more complicated than just getting more cardio.
Sure, there are some real cases. But they are just going to learn in 5,10, or 15 years that all these drugs turned out to not be such a good idea, or at least, they weren't such a good idea for the majority of the people that they put on them.
I know people always say this, but, they did not have focusing medicine back in the day. Maybe daddy's belt growning up, but that's about it.