What Kinds of Exercise Make You Smarter?

In An Exercise Trick To Make You Smarter, I introduced a compound called Brain Derived Neurotrophic Factor, or BDNF, which is a protein that acts on neurons in your central nervous system (CNS) and peripheral nervous system (PNS) to help your existing neurons survive and thrive and also to encourage the growth of new neurons and neuronal connections (also known as “synapses”). In that post, I recommended making the BDNF flow by fitting in an aerobic 20-45 minute run, bike ride, or other bout of cardio on the morning of any day in which you have high intellectual demands.

Then I recently tweeted:

“Here’s why I like to go on a nice easy walk, simple nasal breathing jog or bike before a big cognitive task or speech: http://ift.tt/2fVFyji”

So what got me so interested once again in exercise and your brain? As you’ve probably guessed if you’re a long time reader or listener, it is, yes, a new study. Let’s dive into what that study discovered, then you’ll get a few quick and dirty tips on using intervals, weight training, and cardiovascular exercise to increase BDNF and elicit a few other brain boosting effects too.

The Link Between Exercise and Intelligence

In addition to knowing about BDNF for brain survival and growth, you need to be familiar with another term: neuroplasticity. Neuroplasticity is the ability of your brain to engage in the strengthening (or weakening) of existing neuronal pathways (called synaptic plasticity), or the establishment of entirely new neurons and connections (called structural plasticity).

We already know that compared to strength training, aerobic training can cause a much more significant BDNF boost, likely due to the fact that BDNF stays more “localized” to muscle tissue in response to strength training. We also know that aerobic running can inhibit the lowering of neuroplasticity that can occur after a stroke. At the same time, strength training is not useless for cognitive function. For example, one recent study showed that strength gains (not aerobic gains) in response to training were significantly associated with cognitive improvements.

But what about intense exercise that doesn’t cause a big, localized muscle “pump” that may keep BDNF in the tissue? It turns out that sprinting is a fantastic way to boost an sprinting is a fantastic way to boost BDNF and that elite sprinters have higher levels of BDNF than amateur sprinters. This is probably because intensity is a key trigger of exercise-induced BDNF increases.

Now let’s take a look at what the latest research reveals.

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How Long Should You Exercise to Get Smarter?

In a 2015 study entitled Dose-response relation between exercise duration and cognition (which emerged since my first episode on this topic), participants took a cognitive test called a Stroop task, in which they had to identify the color of colored words flashing on the screen. For example, the word "red" might flash in red letters, then later the word "red" might flash in green letters, and participants had to sort through such confusion. The exercise they performed prior to this task was moderate-intensity cycling (at 65% intensity), for 10, 20, or 45 minutes.

It turns out that the best results were produced with 20 minutes of moderate-intensity cycling versus 10 or 45 minutes. The 45 minute session (technically 55 minutes if you include the warmup and cooldown) actually produced worse results than the group that didn’t exercise at all!

So for aerobic cycling, it appears that the sweet spot is about 20 minutes (or 30 if you include the warm-up and cool-down used in the study).

How Hard Should You Exercise To Get Smarter?

The newest study on exercise and the brain, entitled Impact of Exercise Intensity and Duration on Postexercise Executive Function, investigated not only the duration of exercise, but also the intensity.

In this study, twelve healthy male subjects performed a cycling workout at a low intensity (30%) for 20 minutes, a moderate intensity (60%) for 20 minutes. They also did a 40 minute low intensity protocol that was matched for volume with the 20 minute moderate training protocol. In a second part of this study, fifteen male subjects performed moderate intensity exercise for ten, twenty or forty minutes. They used a Stroop test in both parts of this study: before exercise, immediately after exercise, and during the 30-minute, post-exercise recovery.

For part one of the study, the researchers found that the post-exercise executive function improvement was sustained for a longer period of time after the 20 minute moderate intensity protocol than after the 40 minute low intensity protocol, and was also sustained for a longer duration after the 40 minute low intensity protocol compared to the 20 minute low intensity protocol.  For part two of the study, the 40 minute moderate intensity won out over the 10 minute and 20 minute moderate intensity.

So allow me to summarize: it appears that 20 minutes of moderate intensity at 60% improves executive function, especially compared to 30% intensity at both 20 and 40 minutes, and it also appears that if you have 40 minutes available for moderate intensity exercise, that’s even better. Just don’t creep up close to an hour of moderate intensity exercise or you begin to see a drop in cognitive function. 

Summary

Ultimately, based on this research, if you want to make yourself smarter for the day, increase BDNF or increase neuroplasticity, you should include exercise sessions such as:

-Moderate intensity 20-40 minute aerobic sessions, preferably fasted in the morning (fasting also increases BDNF)

-10 x 100 meter sprints

-Trampoline jumping for 10 minutes

-Any game that includes sprinting or hopping, such as basketball or tennis

Finally, you’ll get less bang for your buck from: A) weight training, and B) voluminous moderate intensity aerobic exercise.

Do you have questions, comments or feedback about what form of exercise makes you smarter? Join the conversation at http://ift.tt/1PKzcip.