Swimming and Mental Health?

It turns out swimming is incredibly healing—and I now have data to back up what my body has been telling me all along.

Recently, I measured my EEG brain waves on two very different days using a biofeedback headset. Biofeedback is a way of measuring what’s happening in the body—things like brain activity, heart rate, or muscle tension—and reflecting that information back to you. It doesn’t judge or diagnose; it simply shows you how your nervous system is behaving in real time. In many ways, it’s like holding up a mirror to your internal state.

On one day, I didn’t go into the pool at all and was mostly sedentary. On another day, I spent about an hour swimming and soaking in the hot tub before taking the same measurement. I used the IHNNK EEG headset from Serenibrain for both readings.

The difference was striking.

On the non-swimming day, my biofeedback results showed 73.16% active (non-calm) brain waves, suggesting my nervous system was largely in a heightened, activated state—busy, alert, and not especially settled.

On the day I swam, the results flipped. My EEG showed 72.67% calm brain waves.

That’s not a subtle shift. It’s nearly a reversal of my nervous system state.

What stood out most wasn’t just that swimming helped, but how clearly it helped. Biofeedback makes the invisible visible. It translated a felt sense—“I feel calmer after swimming”—into something measurable. The water, the rhythmic movement, the buoyancy, and the warmth of the hot tub all seem to work together to support nervous system regulation. My brain looked calmer. More coherent. More at ease.

This was just one comparison, but it’s an easy experiment to repeat, and I plan to do exactly that. Still, even a single data point like this feels validating. It confirms that what feels regulating and restorative in my body is showing up in my brain.

Sometimes healing isn’t about pushing harder or doing more. Sometimes it’s about finding the environments that let your nervous system finally exhale. For me, water is one of those places.

Before going in the pool, just sitting at home being sedentary.

After being in the pool and hot tub for an hour or so.