“Victor seven tango three one seven…no wait…three one nine…no one seven, one seven! It’s one seven for sure.” Spurted the tired athlete to the official.
“Wrong! Thirty burpees.” demanded the Spartan judge who was checking each racer's memorized codes.
In the obstacle course (OCR) world racers spend countless hours monthly training their bodies to handle climbing ropes, crawling under barb wired, swimming in frigid lakes but what they might not know is that their physical training is making their brain healthier too. Plus, there’s an amazing and simple neuroscience hack that can help every athlete age smarter – and the memorization codes during each Spartan Race hold the key.
When I was researching my upcoming book “Fear is Fuel” I spent a day with Professor John Ratey at Harvard University. Dr. Ratey, who is not just a professor at Harvard but also a practicing M.D. wrote a breakthrough book called “Spark.” (put it on your 202 reading list!) In which he shows the dramatic impact of exercise on brain function and health. He argues that schools need to put more exercise back into the curriculum (not just for our obesity epidemic but for brain health.) His findings intrigued me enough to ask how exercise impacts fear and courage. He said it quite succinctly:
In order to cope with anxiousness, for instance, you need to let certain well-worn paths grow over while you blaze alternate trails [in your brain]. By understanding such interactions between your body and your brain, you can manage the process, handle problems, and get your mind humming along smoothly. If you had half an hour of exercise this morning, you’re in the right frame of mind to sit still and focus on this paragraph, and your brain is far more equipped to remember it.
Ratey, John J. Spark: The Revolutionary New Science of Exercise and the Brain (p. 6). Little, Brown and Company. Kindle Edition.
More recently researchers have shown that aerobic exercise can not only help increase what we call neuroplasticity – the growing of new brain cells – but also increase critical parts of the brain that deal effectively with fear.
The limbic system handles our fear response and two core components of the limbic brain are the hippocampus and amygdala. Exercise increases the volume of those areas making us better able to turn the fear reaction on and off. What you can learn in my book is that choosing courage can be done by anyone; using an area of the brain called the sgACC. This requires shutting off the reaction of the amygdala and engaging the prefrontal cortex. Exercise makes this easier. That’s right exercise can help build confidence and courage.
Neuroscientists have proven a clear link between aerobic exercise and benefits to other parts of the brain, especially growth of the prefrontal cortex (PFC), or what I refer to as the “adult supervision” for the brain. The augmentation of the PFC creates optimal executive cognitive functions, especially strategy, planning, courageous decision-making and rapid changing of focus—all skills that, like your memory, decline with aging and decline exponentially with Alzheimer’s. Researchers think added connections between existing neurons, besides the birth of new neurons, creates the beneficial effects from exercise on the prefrontal cortex and other brain regions beyond the hippocampus.
If you are over 40 you also need to know that exercise combined with a cognitive challenge can stave off all kinds of issues associated with mental decline.
Several studies starting from 2011 show that aerobic exercise combined with a challenging mental task (a video game, memorizing numbers or quotes, planning strategy) can reduce cognitive decline and in fact can increase mental processing capabilities. Combine exercise with challenging mental tasks (like memorizing numbers during an obstacle course race) and focus on a healthy diet and you can actually get smarter as you get older.
A surprising finding over the last five years is that many people have Alzheimer’s without displaying any symptoms because their lifestyle has helped them create cognitive workarounds. One of the reasons this happens is intense exercise increases something called brain derived neurotrophic factors (BDNF). BDNF has a critical role in memory function and is one of the first things to go as we age. 
From Scientific American Atrtcile "Why your brain needs exercise." this graphic shows how the BDNF process works:
The bottom line is: exercise more as you age, eat a healthy diet low in carbohydrates and heavy on plants and try to challenge yourself mentally while you exercise. There’s no reason we shouldn’t be living to 100 and playing tennis, running obstacle course races, skiing or doing other activities we love well into our 80s and 90s. The key is to plan for that when you’re in your 30s and 40s and you grandkids won’t have to sit around watching you drool but can chase you down a mountain instead, of course using fear as fuel!