When Jamie Johnston told her husband in 2011 that her life needed to change, the problem was right in front of her face.

The issue wasn’t Dana, her loving husband whom she’d just recently married. Their marriage was great back then and still is today, nearly six years later. The trouble was on the kitchen table: a huge plate of Tater Tot Hotdish, a calorie-dense casserole of tater tots, cream of mushroom soup, hamburger and cheese.

“That used to be a common dinner choice,” Johnston says.

Photos of Johnston before (left) and after her weight loss.

Johnston weighed 350 pounds at the time. Her employer, Cleveland State University, had just announced they would make a Weight Watchers program available to anyone who wanted to participate. Johnston, who’d been heavy all of her life, was ready to give it a try.

“My husband was nothing short of supportive,” Johnston recalls. “He said, if you’re not happy with yourself, and that’s something you want to pursue, then do it.”

Neither of them could have guessed that the conversation was the first step in Johnston’s journey from overweight woman to fast runner. Five years later, the 33-year-old Johnston is 190 pounds lighter. She also holds medals from several races—including some for top-three finishes. Today she’s running about 50 miles per week and has her sights set on earning a spot in the Boston Marathon

“When I entered the running world, I didn’t realize that I could be this fast,” Johnston says.

How could she? When this all started, her first goal was just to walk around the block.

Small Changes, Big Results

Jamie Johnston at her home in Broadview Heights, Ohio, photographed before she lost 185 pounds.

During those first few weeks, Weight Watchers taught Johnston about portion control.

The weight came off slowly. As it did, Johnston started taking walks around her neighborhood in Broadview Heights, a suburb of Cleveland. She lives in a cul-de-sac that is seven-tenths of a mile long. Johnston had to work her way up to walking one full lap. Eventually, she made it through two. Then Johnston set a new goal.

“My mom is a breast cancer survivor,” Johnston says. “I thought, how cool would it be to walk a 5K in her honor?”

Johnston at her first-ever 5K walk.

That fall, Johnston realized her goal (and surprised her mother) by walking in the Susan G. Komen Race for the Cure in downtown Cleveland. Walking the 5 kilometers, or 3.1 miles, took Johnston more than an hour. But she did it.

“It was raining and kind of a mess,” Johnston says. “I was struggling, and I remember seeing all of these runners. And I remember thinking, how cool would it be to be able to run this thing?”

She had her next big goal. A little less than a year later, a much smaller Johnston toed the line again, this time at a Race for the Cure in Akron. She was ready to run. She’d spent the intervening months decreasing her body weight and increasing the amount of exercise she was doing. The result? She completed the same distance in about half the time.

Months after walking her first 5K, Johnston took up running.

“I remember at the end of it thinking that I was going to die,” Johnston says. “But I also thought it would be cool to come back and do it again.”

Johnston has run Akron’s Race for the Cure every year since. For the past three years, she’s been one of the race’s top three finishers.

A Fast New Life

The pants Johnston used to wear could fit her two to three times over today.

By the time she took on her first half-marathon in May 2013, Johnston’s body was completely different. She had lost more than 180 pounds. She would run by windows and not recognize herself in the reflection. Johnston says she’s still adjusting to the change today.

“When you’re so big your whole life, you have this idea of what your body looks like,” Johnston says. “So you might walk between a chair and a wall, estimate the amount of space you take up, and worry that you won’t fit. In actuality you fit just fine, but in your head you still weigh 350 pounds. So that has been a transformation that I’m still working through.”

Johnston’s goal for that first half-marathon was to finish in under two hours, which is about 20 minutes faster than the median half-marathon finish time for women.

Johnston’s half-marathon finish time has improved in nearly every race she’s ran.

“I didn’t realize that in the running world, that’s a fast time,” Johnston says.

When the day of the half-marathon came, Johnston crushed her goal. Her finish time was 1:53:42. Waiting to congratulate her at the finish line were her parents, who travel from Wisconsin to watch all of her big races, and her husband, Dana, who has lost nearly 80 pounds himself since that 2011 conversation.

Johnston continued to push her distance boundaries, finishing her first marathon in 2014. That first attempt took her a little more than four hours, but she cut her time down to 3 hours and 49 minutes when she returned to the race last year. If she can achieve a similar improvement in her next long race, the Cleveland Marathon in May, Johnston could reach the 3 hours and 35 minute threshold she’d need to qualify for a spot in the Boston Marathon.

“That would be the ultimate,” Johnston says about the prospect of running in America’s oldest 26.2-mile race.

The now-speedy Johnston regularly finishes in the top three at races.

Johnston is training aggressively to achieve her goal. She’s following a training plan created by the Hanson’s Running Club of Rochester, Michigan, which is famous in running circles for its high-mileage approach. (The group is also known for producing marathoner Des Linden, who just earned a spot on the U.S. Olympic Team traveling to Rio this year.)

Her schedule has Johnston running six days a week, totaling 50 miles or more. As if that weren’t enough, she also takes part in a one-hour spin class and lifts weights twice every week.

“The amount of energy that I have [now that I’ve lost the weight] is through the roof,” Johnston says. “I have good days and bad days, but I’m fortunate to feel that I have more good than bad. I feel like my body is just getting stronger.”

Johnston (in pink) passing runners near the end of her most recent marathon.

Johnston says her weight loss days aren’t over. She wants to shed a few more pounds between now and the Cleveland Marathon on May 15. But she won’t be using Weight Watchers this time. She dropped the program in December. It wasn’t meeting her needs now that she’s an athlete.

“I love Weight Watchers, I think it was a great start for me, but I had to break up with the program,” Johnston says. “I don’t think they tailor the program for someone doing this much activity.”

Instead, Johnston now follows a program called “If It Fits My Macros,” which tracks the grams of protein, fat and carbohydrates she eats each day. The plan allows her the flexibility to eat some of her favorite foods, including her guilty pleasures like cupcakes.

Occasionally, and in a much smaller quantity, she’ll even have Tater Tot Hotdish.

“It’s a once-in-a-while dish [now],” Johnston says.

***Jamie Johnston shares recipes, tips and photos from her journey on Instagram at @CupcakesForPRs. The Cleveland Marathon takes place on May 15.