For years, runners have believed that their sport makes them too tight and that they should turn to yoga to lengthen their muscles, become more flexible and thereby develop into better runners. It turns out, though, that the opposite may be true: Coaches and physical therapists now say that bending like Gumby may, in fact, cause problems.

“When it comes to running, flexibility is overrated,” says Steve Magness, author of “The Science of Running” and cross country coach at the University of Houston. “Research shows that if you are too flexible, you are a less efficient runner.”

As Magness explains it, our muscles and tendons are designed like springs. As our feet hit the ground during a run, those springs release stored energy and propel us forward. If the springs aren’t tight enough, they can’t do their jobs properly.

Some research has touched on this in the past, but the idea that tightness can help runners is getting a new look in this era of yoga popularity. A 2010 study of eight distance runners looked at their overall running economy relative to flexibility.

The participants performed the classic “sit and reach” test before running, and their oxygen uptake was assessed. “We saw that those who were most flexible were the least efficient,” says Tamra Llewellyn, an assistant professor of health and human performance at Nebraska Wesleyan University and a co-author of the study. “Those with lower flexibility had greater elastic energy storage in their muscles and didn’t use as much oxygen.” In other words, their muscles could do more with less, allowing them to get more out of each stride at a lower level of exertion.

Yet the perception persists that more flexibility — even as much as that of a yogi — is better for runners. “It’s a myth we’ll probably fight forever,” Magness says. “We’re all taught from a young age to stretch to improve flexibility and performance.”

Running coach Jason Fitzgerald of Strength Running, a Denver-based coaching service, says he sees this notion everywhere: “People get the idea that runners need the flexibility of gymnasts, and it’s just not true. You do need the right amount of flexibility to go through the range of motion for your sport. But you don’t need advanced yoga moves to get it.” As Fitzgerald explains, running requires only a limited range of motion, all in one plane. Stretching and yoga aim to increase that end range, which is more than necessary for running.

Instead of seeking extreme flexibility, says Gene Shirokobrod, a physical therapist in Maryland, runners should focus on exercises that target abilities that need improvement, such as strength and range of motion. Those attributes are different from flexibility, and they’re more important for runners.

Shirokobrod says “there are broad concepts in running that help ward off injury and improve running efficiency, such as ideal hip extension, glute strength and sufficient ankle mobility,” he explains, “and for some reason, runners often skip this work.”

Range of motion is the ability of joints and muscles to move well and far in a given direction. Runners, for instance, benefit from good hip extension because this is the origin of most of a runner’s power, allowing them to push into and off the ground, Magness says. Hip flexibility, however, is simply how far a muscle can be stretched in a mostly static state. If runners stay injury-free, odds are their range of motion is just fine. “You should be striving for the range of motion that your event requires of you,” Magness says. “As long as you have that, there’s nothing to worry about.”

He encourages runners to swap out more-static yoga-type moves intended to improve flexibility with dynamic movement. A 2015 study showed that a dynamic warm-up enhanced performance in a small group of well-trained middle- and long-distance runners. Dynamic exercises performed in the 10 minutes just before running prime the body to go through the required range of motion.

A dynamic warm-up routine, Fitzgerald says, can include such movements as lunges, high-knee skips, squats and sideways leg swings.

This is how 58-year old Mike Fronsoe, a retired pharmaceutical sales rep from Florida, helps ensure he has the right range of motion. “I use a dynamic routine” of about 20 different exercises, he says. On days when he’s strength training, he adds weights to some of those moves.

Since starting the routine about a year ago, Fronsoe says, he has had his first solid year of injury-free running, which has also helped him increase his mileage.

A small 2006 study of soccer players by Alain Aguilar, a lecturer at the Department of Exercise and Sport Science at the University of North Carolina at Chapel Hill, compared the value of dynamic warm-ups with traditional stretching and with no warm-up at all. The results showed that the group who performed the dynamic warm-up had better range of motion and muscle strength than the other two.

A dynamic warm-up might include a wide variety of movement, but it should always start with something familiar to the body, says Aguilar, whose 2006 study was done for his master’s degree. “It should be low-level movement similar to [what you use in] your specific sport,” he explains. “It could be things like walking lunges, inchworms or leg swings, and progress from there to some short, progressively faster run intervals.”

This dynamic work can be especially important for runners who spend much of their days sitting at desks, where hip flexors, which help hips achieve full range of motion, can become shortened and where glute muscles can grow weaker due to inactivity. “Many rehab exercises like donkey kicks, lunges and fire hydrants work well here,” Fitzgerald says, “because they wake up the muscles by putting them under some tension.”

He says he guides his running clients toward a “sandwich” approach to training. “I encourage them to spend 10 to 15 minutes with a dynamic warm-up, followed by their run and then some sort of cool-down routine. The cool-down post-run is where some light yoga movement can be a nice way to end an easy run.” Here yoga can bridge the gap between fast-paced movement and a return to a sedentary state by providing a light cool-down.

For those still intent on stretching before running, Matthew Sedgley, a primary-care sports medicine physician with MedStar Health, sums it up like this: “Dynamic as your warm-up, static as your cool-down and never ballistic — bouncing — stretching.”

None of this is to say that yoga isn’t good for you, especially for overall health. Its benefits can include lowered stress levels, improved balance and better sleep, in addition to greater flexibility for those who need it. But for a runner, the dynamic warm-up, range-of-motion work and strength training may keep you running better and for longer.