A Neuroscientist Explains the Brain-Boosting Benefits of Swim, Bike, and Run

In 1974, when the first modern-day triathlon took place in San Diego, the word “fitness” was just entering the lexicon. Exercise science research was booming and people were beginning to appreciate the physical benefits of exercise (and of slightly crazy sounding sports like triathlon). But, the psychological and neurological effects weren’t yet known. Fortunately, around the same time, neuroscientists were building the first brain imaging machines, enabling a peek inside the brain in a way that hadn’t been possible before. Eventually, exercise science and neuroscience converged, which allowed for researchers to explore the effect of physical movement on the brain.

Exercise, in general, is known to improve cognition, which is the key ability to process information, formulate thoughts, make decisions, and respond appropriately. Now, research is revealing how specific types of exercise uniquely contribute to changes in the brain’s structure and function, which may explain why exercise elevates our psychological and emotional wellbeing. Since we care about multisport, let’s explore how swimming, biking, and running benefit the brain in different ways.

This is your brain on swimming

We’ve all reaped the physical benefits of swimming. It’s a low-impact, whole body workout that improves cardiovascular health and increases strength. Pretty solid! We’ve likely also experienced the psychological benefits, such as stress reduction and greater joy. But, we may not be as aware of the direct positive impact on brain function. In a 2019 study, researchers found that one moderately intense 20-minute swim workout improved a specific aspect of cognitive functioning called visuomotor processing. Or, more simply put, reaction time.

If a single swim workout improves cognition, then what effect does regular swimming have on the brain? One study explored this question, measuring another aspect of cognition, memory, after single or multiple swim sessions. While there were no improvements in memory after a single swim, both short- and long-term memory improved after multiple swims. What’s really cool is that these memory boosts were rapid, happening quickly after swim workouts. This may help explain why your mind feels sharper after a few weeks of swim training. The benefits did eventually level off, however, suggesting that perhaps in order to maintain memory improvements, swims may need to increase in intensity or duration over time (which, for anyone training or swimming consistently, should happen anyway). Lastly, there’s evidence to suggest maintaining a swimming routine as we age may help protect the brain against inflammation and cell death in the hippocampus (the seahorse shaped structure largely involved with memory) and improve both attention and brain-processing speed.

So, all the time spent in the pool or open water swimming may decrease your reaction time, improve your short- or long-term memory, increase your attention and brain-processing speed, and protect against inflammation and cell death. If that’s not motivation, I don’t know what is.

RELATED: A Complete Guide to Triathlon Swimming

The brain-boosting power of riding a bike

Spinning our bike wheels gets our mental gears going as well (I never shy away from a pun). One study showed that after a single, 30-minute workout on a stationary bike, participants performed better on memory, reasoning, and planning tasks—and that they were also more efficient at performing these tasks. Another stationary bike study examined the effect of a single workout on depressive patients. The results revealed a decrease in the stress hormone cortisol and a corresponding decrease in subjective depressive symptoms. Other studies have demonstrated the following brain-boosting benefits after cycling: increased blood flow to the brain; increased levels of molecules, such as brain-derived neurotrophic factor (BDNF), that stimulate the growth of new brain cells; and greater white matter integrity, which serves as a proxy for enhanced connectivity in the brain. The neuroscience research on cycling is still in its infancy, but so far, the evidence is clear: cycling is good for the brain’s structure and function.

RELATED: Single Sport Focus: 4-Week Bike Training Plan for Triathletes

Run for better brain health

Running has been extensively studied in neuroscience labs and its brain-boosting benefits are pretty robust. Let’s start with ‘neurogenesis,’ the growth of new brain cells in the adult brain. For a long time, neuroscientists believed that the adult brain was fixed—that once it reached maturity, it was incapable of changing, much less, growing. However, in the 1990s, data finally accumulated and the idea of neurogenesis became mainstream. In the years since, running (and other aerobic workouts) has proved to be an incredibly effective mechanism for the creation of new brain cells. One study showed that running increased neurogenesis in the hippocampus, which has been associated with learning and pattern separation. Interestingly, this effect wasn’t seen after high-intensity interval training (HIIT), although it is likely that HIIT positively affects the brain in other ways.

Another brain-boosting effect of running is its ability to increase our resilience to stress. Researchers have recently discovered that running stimulates production of a little-known molecule, called galanin, in a part of the brain called the locus coeruleus. This matters because increased levels of galanin are correlated with the brain’s ability to adapt to stressful situations. That helps explain the neural mechanism underlying the cliché, “it doesn’t get easier. You just get stronger.” Other studies have shown that running may also improve fine motor skills and protect the brain from emotionally negative stimuli.

So, the next time you’re struggling on a long (or short) run and need an extra push, imagine that your brain is sprouting new cells and being boosted by all sorts of beneficial chemicals.

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Brain bonus: Take your multi-sport outside

The brain-boosting benefits of swimming, biking, and running are clear—and the research is only just beginning. One thing to keep in mind is that cognitive improvements seem to be even greater when the brain is engaging in an outdoor environment. So, when you can, ditch the trainer and the treadmill for the pavement and the trails.

Ultimately, however you choose to swim, bike, and run, know that your brain is thanking you.

RELATED: Mental Health Used to be Taboo in Endurance Sports. These Researchers Are Changing That