Friday night, before the race, a dozen women gathered in a park in St. Paul to practice what to do when someone attacks you during a run.

Instructor Suzanne Dougherty ran through rapid-fire worst-case scenarios. Say a guy grabs you by the wrist, what do you do? How do you break away from someone who has you in a bear hug with your arms pinned to your side? What if someone grabs you by your ponytail and tries to drag you to the ground?

Overhead, the bright pink banners set up for the Women Rock half-marathon snapped in the wind around Upper Landing Park. Race organizers had offered this self-defense class before other races, but Mollie Tibbetts’ bright smile wasn’t beaming out at us from endless breaking news alerts in those cities.

“You’re running and he pulls your ponytail,” said Dougherty, who learned Krav Maga, the self-defense system developed for the Israeli military, after she was mugged on her way home from a party one night. “If you try a tug-of-war, you’re going to lose. Your hair’s attached to your head, right?”

Instead, she demonstrated this: You step back toward your attacker and use that momentum to whirl around and deliver a vicious elbow or punch to the head, followed by an annihilating kick to the groin.

The class watched her intently, unsmiling. These aren’t hypothetical situations to anyone who’s been followed by a creep while jogging or heard footsteps approaching in a dark parking lot or crossed the street to avoid someone, only to watch him change course and follow.

For an hour and a half, the class paired off and practiced gouging out each other’s eyes. We broke out of chokeholds and whacked our forearms into our attacker’s windpipes. We raked our running shoes down an imaginary assailant’s shins and stomped his instep. We clawed at faces and kicked at groins.

I don’t know if any of it will save me some day, but I felt better afterward. But I thought about Tibbetts, 20, stabbed to death during an evening run around her small hometown. Or Mai Yer Cha, stabbed to death in a Minneapolis parking ramp last summer while trying to protect her friends from an attacker. The 23-year-old woman attacked by two men with a stun gun during a May run through Como Park. The University of Minnesota pre-med student who was pepper-sprayed, thrown to the ground and raped as she was scraping her car windshield.

They didn’t do anything wrong. Nothing that happened to them was their fault. No amount of Krav Maga can guarantee your safety in a world where trolls lurk under bridges and sharpshooters target concert venues and people plant bombs along marathon routes.

Dougherty, who has a daughter around Mollie Tibbetts’ age, has a few common-sense pointers for anyone heading out on a run. Or, say, walking outside the Minnesota State Fair like I was Friday when a guy approached with a request to let him build a Spam sandwich out of his face and my breasts. I glanced down at my Spam T-shirt and politely declined, because I hadn’t picked up all those pointers about eyeball gouging yet.

So when you’re out there on a run, if you have to listen to music, pop out at least one earbud so you can hear what’s going on around you.

Don’t follow the same running route every day.

Don’t post about it on social media beforehand.

Don’t walk the streets with your face buried in your phone.

Stay alert. Stay safe.

“Ultimately, what I’m saying, is, you can’t be paranoid, and you can’t fear living,” Dougherty said. “But these crazies just pop out of nowhere, so you just need to be able to keep your wits about you and don’t make it easy for them.”

On Saturday, the starting line in Upper Landing Park was crowded with runners who hadn’t let the bad in the world stop them from lacing up their shoes and heading out the door.

If I’d been there — and not sleeping off Friday’s State Fair Pronto Pup excesses — I might have told those runners the story of my dad’s bike.

When Dad died, I sold his old bike to someone tall enough to ride it. But before I let it go, I unclipped the ancient bike computer he’d used to track his mileage and attached it to my bike.

Every time I went for a ride, it felt like I was adding to Dad’s miles.

As all those running shoes hit the pavement in St. Paul, maybe they added a few more miles for Tibbetts too.