According to a study out of the UK, just 20 minutes of exercise can clear that brain fog you have when you don’t get enough sleep. The study found that cognitive performance improves during a session of moderate intensity exercise, regardless of a person’s sleep status or oxygen levels. “The finding significantly adds to what we know about the relationship between exercise and these stressors, and helps to reinforce the message that movement is medicine for the body and the brain, said Dr. Joe Costello of the University of Portsmouth’s School of Sport, Health & Exercise Science.