So, I don't mean to imply that there is a units equivalency -- 1 minute of exercise is not the same or similar to 1 minute of some type of mental activity. It's

So, I don't mean to imply that there is a units equivalency -- 1 minute of exercise is not the same or similar to 1 minute of some type of mental activity. It's no good to say "this experiment doesn't use at least N minutes of intervention, where N comes from this totally different process and unit system having to do with the effects of e.g. bench presses". But that isn't what I'm saying. What I'm saying is, if you give an intervention of thirty minutes of activity a week and see no change, it's a pretty reasonable to conclude "30 minutes a week for six weeks is not an effective dose" and not jump all the way to "This intervention has no effect". This is why I highlighted how low the 'dose' of the intervention was. [I also am relying on my understanding of Dual N-back, language learning, and other mental tasks, and the turnaround time for them is substantially longer -- and thus requires a higher dose -- than starting from a similar place in exercise. This context is useful only for general dose estimates {{ even 10 hours a week might not be enough to learn a language, certainly not in six weeks }}, but not necessary for the comparison.] Does that address the substance of your objection?