You can play various “tricks” on yourself to generate the release of this chemical. Visualizing an activity generates a similar metabolic response to actually doing it. One study found that picturing yourself doing a finger exercise increased muscle mass by 22 percent, which was close to the 30 percent achieved by doing the exercise for real. (For those thinking this sounds too good to be true, remember that you still have to put in the effort, a lot of effort, to keep mentally focused on doing the exercise.)
