In their study, post-doctoral researcher Sabrina Segal and neurobiologists Carl Cotman and Lawrence Cahill had people 50 to 85 years old with and without memory deficits view pleasant images - such as photos of nature and animals - and then exercise on a stationary bicycle for six minutes at 70 percent of their maximum capacity immediately afterward.One hour later, the participants were given a surprise recall test on the previously viewed images. Results showed a striking enhancement of memory by exercise in both the healthy and cognitively impaired adults, compared with subjects who did not ride the bike.