Many studies have shown that exercise is good for the brain, but the link between exercise and memory has been unclear.  A group of researchers looked at the substances that are produced by muscle cells in response to exercise.  One of those substances, a protein called cethepsin B, contributed to the growth of new cells and connections in the hippocampus, a region of the brain that is associated with memory.  After finding that high levels of cethepsin B improved memory in mice and monkeys, the group conducted a similar study involving 43 sedentary university students.  Half of the students remained sedentary while the others exercised several times each week for 4 months.  The students who exercised experienced an increase in cathepsin B levels and improved on a memory task (reproducing a geometric pattern from memory).

Skipping your workout to study?  Think again.  You may do better on your exam after you exercise.

Sources:

http://www.npr.org/sections/health-shots/2016/06/23/483245084/a-protein-that-moves-from-muscle-to-brain-may-tie-exercise-to-memory

Moon et al., Running-Induced Systemic Cathepsin B Secretion Is Associated with Memory Function, Cell Metabolism (2016), http://dx.doi.org/10.1016/j.cmet.2016.05.025