Leslie Barker / The Dallas Morning News

DALLAS — Despite having run 15 marathons, four 50Ks and countless half-marathons, Blanca Gonzales still harbors a fear of mile 17. She traces it back to her fourth 26.2-mile race, in Austin, Texas, in 2004.

“I followed my training, didn’t miss a run,” says Gonzales, 48, who lives in Arlington, Texas. “I carbo-loaded, hydrated, and on race morning at mile 17, I felt like someone took every bit of energy from me.”

She finished, but mile 17 still looms large. So she’s devised a plan to keep from what’s called hitting the wall in marathon-speak: energy gels every four to five miles, hydrating no matter the temperature.

“Once I hit mile 15, I don’t think. I just run for the next three miles. I turn on my music, I count runners,” she said.

Some fears, such as weather, are not in anyone’s control. Others, such as Gonzales’, can often be dealt with fairly simply. We asked Keri Wilson, a six-time marathoner and a training coach at Luke’s Locker, for some solutions.

Hitting the wall

Wilson acknowledges that 18 miles (around the time many runners “bonk”) is a long way to run, plus there’s still another eight to go. That, she says, “is enough to play mind tricks on anyone.”

She suggests eating a snack if an energy gel isn’t working. Remember, you’re not the only one with these feelings, so “sidle up to another runner and start a conversation,” she says. Or do some math, sing a song, play a game in your mind.

Getting injured midrace

“Heaven forbid you face-plant at mile 4,” said Wilson, which she saw while running the Philadelphia marathon, “or something pops at mile 20, or your bad knee becomes a searing knife pain at mile 13,” she said. “You have to know your body and determine if this is a niggle or real pain.”

The more hours you’re running a race, the more the pain seems to move around, she says. Take inventory of your body and see if the pain is temporary. If it continues, whether because of chafing or a blister or a persistent side stitch, stop at the med tent.

“They’re here for us,” she said. Don’t worry about wasting time; it’s better to spend a few minutes getting yourself taken care of than to stumble through the last five miles in discomfort.

Needing the bathroom

Bathroom issues happen, Wilson acknowledges. Even if you learn during training what you can and can’t eat, on race day, “nerves can take over.”

What to do? “Stop at the Porta-John? Waste the time standing in line? Risk there not being toilet paper? Or do you wait it out?” she asked.

The longer you do long races, the better you know your body, she said. “It’s funny how you can talk yourself out of having to use the bathroom. The good news is that supported events usually have more Porta-Johns than you can count, so try another mile and see how you feel. Then, if you gotta go, it really won’t burn that much time.”

Not being properly fueled

This goes back to your training, Wilson said. “I don’t usually have this fear because I know what I need to eat the night before and the morning of because I’ve been practicing for weeks. I know I can do gel and fluids consistently until around mile 22, and then I need real food.”

What’s her fuel of choice? A handful or two of Teddy Grahams.

Falling short of your goal

Wilson didn’t hit her time goal in Philadelphia, but she had a great time, she says.

“Go into this with the right mind-set,” she said. “Running a marathon isn’t easy, or everyone would do it. We forget that, because we spend a lot of time training and are around runners all the time, some of whom are much faster than we are. Well there’s always someone faster, right? It’s just another day, and it’s a great day because you can run a marathon!

“If you hit your goal all the time, what would you reach for?”