Scientists are still mystified by one of runners' most common complaints: the side stitch
To kick off the new year, I decided to take on a (for me) unusually ambitious resolution: training for a half marathon.
While I enjoy working out and usually exercise frequently, running has just never been my thing. It's not that I tire out especially quickly. And while I find running harder on my joints than other forms of exercise, that's not really the killer either. It's the dreaded side stitches that keep holding me up.
Sure enough, my first trip to the gym in 2015 ended dismally. Before I'd even made it a mile, I felt that familiar stabbing pain set in just below my rib cage. By the end of the second mile, I was clutching my side and gasping.
Side stitches are among the most common of runners' curses. They're also among the most mysterious. While theories abound on what causes the side stitch, the truth is that scientists aren't completely sure what they are or how to "fix" them.
Theories
The first - and one of the most popular - is that the pain is caused by a spasm in the diaphragm (that's the muscle that runs right across the bottom of your rib cage). Some scientists believe this could happen thanks to a shortage in blood supply or oxygen during running, Morton says.
A second theory suggests that the pain happens when running puts stress on the ligaments underneath the diaphragm, which support the abdominal organs. And a third theory holds that the pain is caused by gastrointestinal distress.
But Morton, who is one of the most-published researchers on the topic of side stitches - now clinically referred to as "exercise-related transient abdominal pain" - says the evidence doesn't quite add up. After surveying 965 people in six different sports, including 439 runners, he felt that their descriptions of their pain supported a new theory, which he first proposed in a 2000 paper published in the journal Medicine and Science in Sports and Exercise.
"Just behind your abdominal muscles there's a... two-layered membrane called the peritoneum," he says. "And in between those two layers of peritoneum, there's a slippery fluid."
When the body is in motion, the abdominal organs can move around and push on the back of the abdominal muscles, Morton says. This can cause friction on the peritoneal tissue, resulting in pain.
While Morton has high confidence in his theory, other researchers are more ambivalent. Matthew Gammons, a sports medicine physician at Vermont Orthopaedic Clinic and second vice president at the American Medical Society for Sports Medicine, says he doesn't have a strong opinion about any of the popular theories.
In fact, he says it's possible that not all side stitches have the same cause, and that all of the above theories might be right.
Prevention
Some runners report that their side stitches seem more common if they eat or drink before exercising.
Morton says that having food in the stomach - or even just gas in the gastrointestinal tract - can increase the pressure these organs exert on the abdominal muscles. This can make the pain worse, or at least more likely.
Since filling up the stomach seems to worsen side stitches, Morton's first advice is not to eat within several hours of running.
Drinking is trickier. It's important for athletes to stay hydrated, so it's not a good idea to stop drinking water before exercising. Rather, Morton recommends drinking water regularly in small volumes throughout the day - "just a mouthful at a time," he says.
Morton also believes that sugary food and drinks can have an even worse effect. Sugar in the gut can draw that slippery fluid out from between the two peritoneal layers, he says - "and when you have less slippery fluid, there's more potential for friction." So, according to his theory, staying away from the sweet stuff might help.
Even posture can have an influence, Morton says. In a 2010 study, Morton and fellow researcher Robin Callister from the University of Newcastle in Australia surveyed 104 men and 55 women and found that people with curving in the upper spine - a type of slouching known as kyphosis - were more likely to suffer from side stitches. "So if you have a recurrent pain and you know that your posture is not fantastic, it could be worth visiting a physical therapist who can help," Morton says.
Gammons, the sports medicine physician, suggests that athletes warm up well before they begin exercising. Working on your breathing technique could also help, he says. He recommends that runners become "a belly breather rather than a chest breather," meaning they should make sure to expand their diaphragm fully rather than taking shallow breaths.
Stopping the side stitch in its tracks
What's the best way to get rid of a side stitch while it's actually happening? A doctor's advice might depend on which theory he or she believes is true. Some experts have advised stretching or breathing in certain ways to ease the pain. But perhaps the only tried-and-true method to relieving side stitches as they happen, according to both Morton and Gammons, is to simply stop exercising for a bit.
"I don't think there's good wisdom in the old adage of 'run through a stitch,'" Morton says, noting that while side stitches don't appear to be dangerous, pushing through the pain might make the athlete more likely to get one the next time he or she exercises.
A brief pause in exercise should be enough to relieve the pain. "If somebody's having a lot of abdominal pain with exercise - if it's really debilitating - that would be a good sign to go see a doctor," Gammons says.
I think it's safe to say that running a half marathon is not in my future this season. I haven't trained on nearly a tight enough schedule so far - and I have to admit, the side stitches have been a major deterrent (along with, of course, your typical post-New-Year loss of momentum).
Maybe by the time I finally work myself up to my first competitive run, the research will be a little more definitive on what exactly a side stitch is and how we can stop them. As for right now, we're still waiting for an answer to one of sports medicine's most common and frustrating mysteries.
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