For trail runners in St. Louis, Thursday nights are the highlight of August. Four weeks in a row, runners gather after work at Castlewood State Park in Ballwin to race the Alpine Shop Trail Run Series, conquering 3 to 5 miles of rocky, hilly trail, the course different each time. The heat and the hills make it a mini adventure. The hot dogs, cold beer, and music at the end make it a party.

Limited to 250 runners, the race series is small and informal. Ahead of the starting gun, runners hang out with friends, stretch, and do a few easy warm-up laps. With such a small group, corrals aren’t needed; instead, runners line up in approximate order of speed. When the race begins, the fastest runners sprint ahead in an effort to avoid getting trapped on the single-track trails behind those with a slower pace. That’s not to say it’s an uber-competitive or unfriendly event — like most races, no matter your speed, it’s ultimately a test against yourself.

After the first mile or so, the group spaces out, runners naturally grouping into small packs according to pace. It’s a mostly silent companionship, everyone working to maintain speed over the rolling hills. I also usually experience a few blissful moments alone on the trail, the only sound my feet hitting the ground and my labored breathing. Eventually, I hear the faraway sound of the finish line and know my work is almost done.

The most difficult part, of course, is the rocky terrain. Most racers don’t actually run up the long, beastly hills but rather slow to a hike, still huffing and puffing. However you make it up to the top, though, it’s worth it for the giant release you feel when you hit the following flat or downhill stretch. Suddenly, running feels effortless and joyful again. Maybe that’s just me, but I’d argue that’s kind of the point of suffering up hills (besides the physical benefit).

True, I’ve cursed many times at the humidity that makes it feel like I’m actually swimming or running at a much higher altitude. But I also find a twisted sort of fun in the challenge, and the heat creates an instant topic of conversation among fellow runners. It’s not all misery, though. August can also bring a glorious evening when the humidity disappears and the temps dip into the 80s. Once you make it under the tree cover, it can almost feel cool…almost.

It’s hard work, but I also feel a little like I’m playing, skipping down hills and (usually) laughing through the water crossing. Most courses include one, and it’s a surprise every time. It might be an ankle-deep refresher, or you might suddenly be up to your shorts. Either way, by this point, I’m drenched in sweat, my legs speckled with dirt, so it feels amazing.

Alpine Shop Trail Run Series

Creek crossings are part of the fun.

Photographers snap photos here, and the results (posted online the next day) shouldn’t be missed. Some runners look triumphant and like total badassses. Some grimace. Some look very silly, making a strange face, their arms stretched out to maintain balance through the stream. (No comment on which camp I usually fall into.)

After crossing the finish line, while the sun and heat fade, runners hang out, sitting on the grass or at picnic tables under the pavilion, eating hot dogs, chips, watermelon, and cookies. Perhaps the only downside to the race series is the lack of options for vegetarians or vegans. But as a meat-eater, I’m grateful for the simplicity. No choices to make — just meat, and salt, and crunch, and watermelon juice dripping down my already-soaked running tank.

Before the evening wraps up, the late-summer bugs start their symphony. The sun almost gone, I feel almost cold, the heat and humidity of an hour or so ago seeming impossible. A handful of winners take home prizes, everything from a voucher for trail running shoes to running socks and sunglasses.

By the time I leave, I’m already pumped for next week. I feel a deep satisfaction in my belly, legs, and heart — the calm that comes from working hard, sweating hard, and playing hard.

Author: Stephanie Zeilenga is a regular contributor to Terrain Magazine.