maybe they could hypnotize patients and "convince" them they got exercise to see what the placebo affect was but if that works, then using the placebo affect is just as valid as exercising, the researchers probably were hoping the "anticipation" of positive results would add to the result. in the final analysis we'll take what benefit we can get.

i think what's really important is researching different exercise regimes and finding the underlying biochemical changes that result in improvement so that can be measured quickly to estimate benefit rather than the more qualitative measures found thru observation, then put that into a pill. might be pie in the sky. and of course trying to find out if there are any permanent changes to the brain.