That post-work out feeling of accomplishment and stress-free bliss is not the only neurological gift exercise imparts. Researchers know that exercise—especially of the endurance variety—boosts our overall brain health and function, including improving learning and memory and slowing cognitive decline in old age. How exercise promotes these mental perks, however, remains poorly understood.MORE: Different Exercises and Their Effect on Your BrainIn pursuit of a formula for exercise’s elixir, neuroscientists and cell biologists from Harvard Medical School and the University of Michigan Medical Center decided to focus on one suspect protein, FNDC5, which is secreted from muscles during exercise. To see what the protein does, they monitored exercise-loving mice that spent most of their time running on a wheel for 30 days. When the mice began producing FNDC5, they observed, it kicked off the rise of another protein, BDNF, in the brain. BDNF helps to form new connections between nerves in the brain, which is essential for learning and memory.With that knowledge in hand, they created an FNDC5 injection and administered it to mice that had not been working out. It traveled through their bloodstream, and a week later, the researchers found, levels of the brain-boosting BDNF protein had significantly increased in the mice’s brains, despite their sedentary lifestyle.“What is exciting is that a natural substance can be given in the bloodstream that can mimic some of the effects of endurance exercise on the brain,” Bruce Spiegelman, Ph.D., a senior author of a November 2013 paper published on the findings, said in a press release.While the results are promising, we’re likely years away from being able to pop exercise pills to keep our minds sharp. The team still needs to investigate whether the increased BDNF actually made the mice any smarter, for example, and further details on the finding’s biochemical mechanics need to be smoothed out—not to mention the lengthy process required to turn a laboratory finding into a bonafide drug. Still, the team concludes, “the therapeutic implications of this are obvious.”In the meantime, you can get your brain benefits the old fashioned way: with some good, solid sweat sessions. We’re feeling stronger and smarter already.QUIZ: Are You Getting Enough Physical Activity? (Psst That’s Not Just Working Out.)