http://well.blogs.nytimes.com/2013/0...ep-exercising/

It appears that there are psychological benefits of exercising provided exercise is done regularly. When the exercise stops, the brain produces fewer new cells, reducing memory and other functions. The brain benefits of exercise disappear quickly when the exercise stops.

. . . the brain benefits “wear off quickly,” said Dr. Michael Mazurek, a professor of neurology at McMaster, who oversaw the study. “This is analogous to what happens to muscle bulk or heart rate following exercise withdrawal.”

Gilberto Xavier, a professor of psychology at the University of Sao Paulo and senior author of the study of hippocampal neurons, agrees. “Brain changes are not maintained when regular physical exercise is interrupted,” he said, adding that, “though our observations are restricted to rats, indirect evidence suggests that the same phenomenon occurs in human beings.”

Meaning that the lessons of both studies point in the same direction. For the ongoing health of our minds, as well as for the plentiful other health benefits of exercise, it might be wise to stick to those New Year’s exercise resolutions (to exercise regularly).