Having trouble remembering what you can’t remember? Just remember to exercise; the rest should follow. New York Times Phys Ed columnist Gretchen Reynolds reports on research conducted at Dartmouth that tested the memories of a group of recruits who did exercise, and a group who did not. Reynolds reports that half of the recruits for the experiment walked or jogged four times a week for at least 30 minutes, while the other half did no exercise. Now it gets complicated. After a month, the volunteers returned to the lab memory tests. But on the day they returned, some did exercise and some did not. Reynolds reports that many, but not all, of those who’d been exercising for the past month significantly improved their scores on the memory and mood tests. In general, those volunteers who had exercised for the past month and who worked out on the day of retesting performed the best on the memory exam. She also tells us that those who had exercised during the preceding month but not on the day of testing generally did better on the memory test than those who had been sedentary, but not as well as those who had worked out that morning. Read more from Gretchen Reynolds. Read an excerpt from the study here.