does anyone have any science behind this?

I'm not quite sure if it would help somebody run faster temporarily like a performance enhancer. It may help a person focus better which could affect performance though.

I could see where it could help somebody improve his or her speed over time. For instance somebofy who may be training for a marathon may benefit. It may help him or her focus better to stick with a training program.

the only way to run faster is (a) practice running the same distance a lot, and (b) build muscle appropriate to your race distance (lots of leg work, especially power movements)

there are some very good internet sites that outline this in vast detail - the short answer is there are no shortcuts (unless one takes steroids - which I do not recommend)

It would increase your stamina to some degree, but make little or no difference with how fast you could run - that's based solely on muscle psysiology

I dont know about Adderal, but Concerta has an effect on how fast i run. The effects are simply that i find it conciderably easier to coordinate a smooth running motion and breath at the same time. Also things like curbs dont cause me to stumble and lose time that way. So in improving my speed and distance judgement, my performance is improved.