“I need to return these shoes. They give me bowel movements.” Seconds earlier the older woman wearing a necklace of real animal bones had walked confidently into the running store where I worked, with a shoe box in hand—always a clear sign of an impending return. Despite the absurdity of her claim (and outfit), I could not argue against the fact that if a pair of running shoes is so utterly uncomfortable they send you running to the bathroom, it is not the right pair for you.

During my two-year tenure working at a specialty running store—a right of passage for every true running bum—I hustled to help people find their dream running shoes.

Ironically it was during this time that I suffered my first significant running injury: the ominous plantar fasciitis. I tried everything to cure it—10 minute breaks to ice my foot, rolling my arch on a tennis ball while I rang up customers, sliding every rigid insole into my shoes and going through stability shoes like toilet paper on race day. Nothing worked. In fact, it continued to get worse.

One day I decided to try on every shoe in the store. Call me Cinderella, but I knew my Prince Charming was living upon the shelves piled high with boxes. As I slid my pain-ridden arch into a pair of white and red Nikes, which I had never even considered before, everything changed. They were really comfortable, and my foot instantly felt a little bit better. Within a few days my foot felt much better and I was back to my normal mileage.

I had always encouraged customers to pick the shoes that felt the most comfortable. What I didn’t realize at the time was that this method is actually supported by science. Dr. Benno Nigg, a research scientist at the University of Calgary who studies biomechanics, footwear and running injuries, found through his study of running insoles, “that comfort is important in [preventing] all movement related injuries to the lower extremities.”

A shoe fitting at a specialty running store typically involves an assessment of the runner’s pronation patterns (the amount one’s foot rolls inward upon impact, thought to cause injuries preventable through proper shoes), choosing the shoe that best neutralizes each runner’s foot strike.

A typical running shoe selection include stability shoes (designed for runners whose feet roll inwards), neutral (recommended for runner’s with a natural amount of pronation) and cushioned (for those who want a softer ride or have feet that supinate, rolling outward upon impact).

Nigg proposes, “that the previous paradigms of cushioning and pronation should be replaced with the two new paradigms of preferred movement path [i.e. natural foot strike] and comfort.” Essentially this theory wipes out the static categories of stability, cushion and neutral shoes as methods to control foot strike. Instead, Nigg proposes letting your feet strike how they want to, putting each runner blindfolded in the driver’s seat, asking: what feels good to you?

Bottom line: There is a science to finding your trail running sole mate—and it begins with trusting your gut.

Comfort is a fairly vague and arbitrary word, though. Trail runner Jamie Mieras, DPM, breaks down what to think about. “The key comfort measures are the stability or flexibility of the shoe and the roominess and fit of the fabric upper at the forefoot, heel and midfoot,” she says. “Also consider whether the shape of the shoe feels like it supports your most efficient or innate movement. Comfort in this sense is a measure of whether your foot feels like it has enough support [and motion] in the right areas to act as your landing platform and springboard as you lope along the trail.”

Still looking to find the shoe that hugs your feet just right every time you lace them up? The shoe that serenades you with the sweet sound of its lugs against the single track? The shoe that never lets you down through multiple training cycles?

Well there isn’t a Tinder app for shoes yet, so get into your local running specialty store armed with these tips, and start playing the field until you find that one that just feels right.

Tips for Finding the Right Trail Running Shoe

1. Trust the experts (and your gut)

Darius Bastani, an employee at Movin Shoes Encinitas in California, with over a decade of experience in the running industry, advises runners to go to a specialty running store but not to overthink anything. “Listen to the person fitting you,” he says.

Although one time during my own running store tenure I did accidentally ask a man in the store to take off his pants instead of his shoes (he didn’t), so use your own best judgment. Most importantly, ask yourself, “Does it feel good?’”

2. Play The Field

When you go to a specialty running store, ask to try on multiple pairs of shoes, preferably across different brands and shoe categories (stability, neutral, minimalist, maximalist). With so many design theories to choose from, what you find the most comfortable might surprise you.

Keep an open mind and don’t limit your options based on what you think you will like. “Buy a shoe that feels great to run in for long periods,” says Mieras. “Don’t buy a pair that seems to make one area ache, puts your foot in an awkward position, or makes your feet feel tired. Also, don’t purchase shoes based on marketing gimmicks, or promises to cure ailments. For pains that persist, grab your most-worn pair and head to your local foot and ankle specialist.”

3. Test Drive

Many stores have treadmills, and it’s always a good idea to try a shoe out before committing. Some stores have regular wear-test nights sponsored by local reps in order to allow you to try shoes without purchasing them. Be ready to answer questions about past injury history and training goals, and a sales person should be able to steer you in the right direction.

4. Narrow It Down

When you know, you know. But if you find yourself with two contenders, run around wearing one of each shoe on your feet. Ideally you will select the shoe that you notice least and that feels like it’s already a part of your foot.

Morgan Sjogren runs wild with words anywhere she can get to with her running shoes and a pen! Follow her adventures, writing and trail racing on Instagram  @running_bum_ and her blog: therunningbum.com.