Stimulants are the first choice for treating ADHD. But we also know that exercise helps to improve concentration.
We know that both stimulants and exercise increase bloodflow to muscles and to the brain by activating the sympathetic nervous system. Is this is the MAIN cause of the effect of improved concentration, rather than, say, specific activation of parts of the brain responsible for learning or planning or something similar?
What I'm asking is, do drugs and exercise have different effects on the brain, what are the differences, and what are the consequences of these differences on concentration and learning? Which is more effective for promoting concentration and why?