India, Sept. 4 -- A study published in the Proceedings of the National Academy of Sciences found that 20 minutes of moderate-to-intense aerobic exercise may protect memory from the effects of severe sleep deprivation almost as well as a 90-minute nap.
The study involved 53 healthy adults aged 18 to 35 who stayed awake for 30 hours. They were then divided into three groups - one exercised on a stationary bike for 20 minutes, another was given 90 minutes to nap, and the third simply sat on a stationary bike without exercising.
Afterward, participants viewed 150 images and returned three days later for a surprise memory test. Those who exercised remembered about 21% more of the images than the control group, while the nap group performed abo...