You've studied hard, had a good night's sleep, eaten a healthy breakfast, and now you're ready for your big test. Consider walking to the exam — 20 minutes of activity has been shown to boost test scores.
The folks at the ExamTime blog highlighted this (along with some other great study hacks) but the studies involved here go back to 2010. Researchers started with children around 9 and 10, and compared the scores of children who got some exercise — usually aerobic exercise like walking, running or playing — before a test with others who didn't get any exercise at all. They found that the children who were active scored better on the tests.
The researchers repeated their tests with a different, more complex test (and a different set of children), and found similar results. The children were then given MRIs, which told the tale:
The M.R.I.'s provided a clearer picture of how it might work. They showed that fit children had significantly larger basal ganglia, a key part of the brain that aids in maintaining attention and "executive control," or the ability to coordinate actions and thoughts crisply. Since both groups of children had similar socioeconomic backgrounds, body mass index and other variables, the researchers concluded that being fit had enlarged that portion of their brains.
Meanwhile, in a separate, newly completed study by many of the same researchers at the University of Illinois, a second group of 9- and 10-year-old children were also categorized by fitness levels and had their brains scanned, but they completed different tests, this time focusing on complex memory. Such thinking is associated with activity in the hippocampus, a structure in the brain's medial temporal lobes. Sure enough, the M.R.I. scans revealed that the fittest children had heftier hippocampi.
Of course, it's difficult to say that what's true for schoolchildren is true for older adults or teenagers, but there's news there too — a separate study drew a line between cardiovascular fitness and cognition in teenagers and young adults, around college age.
Bottom line: your physical health plays a significant role in your mental ability. A morning workout before your exams — or at least walking to the exam instead of catching a lift with a friend — may do you some good.