PHOTO: SHUTTERSTOCK

Around this time each year, I lace up a pair of overworn running shoes and get back outside. Over the course of a few early spring runs, I’ll usually visit the Riverfront Trail in the South Side, the winding paths in Frick and the looping path around Pittsburgh Magazine’s offices on Washington’s Landing.

And at some point, I’ll think about “Unbreakable Kimmy Schmidt.”

The Netflix comedy begins with a group of women freed from an underground bunker, in which they have been imprisoned and convinced the rest of the world is a wasteland. (It’s a dark subject matter, but it works.) When the title character climbs above ground and peers at the intact world around her, she exclaims: “It’s here! It’s all still here!”

Through the colder months, it’s easy to forget how many opportunities we have to walk, run or bike around the city. There are those of us who don’t even blink in the face of cold-weather cardio — I live in constant fear of digging my fiancée out of a snowbank because she insisted on another 10 frosty miles — but for most of us, we let our physical goals take a back seat when the temperature dips.

That’s natural, and it’s always possible to get back in shape when the world thaws. But I get another reminder whenever I take that first spring run: Exercise is not merely a physical necessity, it’s a mental one.

I’m never more calm and clear-headed than I am after a decent run. Friends have commented on the marked change, able to determine that I’ve been running just by the shift in my mood. And while some mental and physiological reactions vary from person to person — the runner’s high is an elusive beast — it is a matter of fact that physical activity improves mental health, often with reductions in anxiety and depression, improved cognitive function and better sleep.

The inverse is also true. Those who don’t get regular physical activity are more likely to suffer from anxiety and depression — and can struggle to regulate their emotions.

There’s a meme about this: “taking a stupid walk for my stupid mental health.” As anyone who has tried it can tell you, though, it works. There is rarely a time when the correct course of action is to remain sedentary; if you think you’re in a bad mood and the recipe is to stay on the couch all day, you’re wrong (barring illness — or a really good streaming binge). There is no mood so foul that it will not be improved by a bit of movement.

And a bit is often all it takes. There’s no barrier to entry, here; it’s not as though these benefits are only conferred on those who can run three miles. Just a little bit of movement can have positive effects.

In Pittsburgh, there are innumerable good places to get that short walk — riverfront trails, sprawling parks and fascinating neighborhood streets. I find joy too in discovering hidden city steps, long-forgotten ballfields and fascinating corners within a few blocks of my home. No matter how long the winter has been, it’s all still here — and we’ll all feel better if we go find it.