Does exercise really make us smarter?

A NYTimes Well piece by Gretchen Reynolds points to an interesting study by Stothart et al., who decided to address a basic deficiency in most studies of the effects of aerobic training on cognition, they don't control for a possible placebo effect. If we expect to be smarter after training, our brains might just respond correspondingly. Stothart et al. found that people queried in an online survey expected a muscle stretching and toning program to have a greater effect on measures of thinking than a regular walking program. In actual experiments, stretching and toning regimens generally have been shown to have little if any impact on people’s cognitive skills. Walking, on the other hand, seems to substantially improve thinking ability. This lack of correlation between expectations and actual outcome suggests that a placebo effect does not explain the improved cognition observed after exercise.