“Muscles often move three-dimensionally so stretching a muscle in multiple planes is of optimal benefit,” says Fabio Comana, an exercise physiologist at San Diego State University.
Stretching is recommended to improve range of motion and reduce muscle stiffness, both acutely and chronically. The question is, “How much is too much?”
FreshSplash, Getty Images (Top) (Left) and Daniel de la Hoz, Getty Images (Bottom) (Right)
Myth: It’s best to hold a stretch for at least 30 seconds.
Fact: Experts recommend holding a static stretch for 10 to 30 seconds, then repeating the stretch two to four times. An exception: Adults over 65 may benefit from holding a stretch “for 30 to 60 seconds because their connective tissue and muscles respond more slowly,” says Tracy Bonoffski, an exercise physiologist at the University of North Carolina Charlotte.
What’s more, the duration of a static stretching session doesn’t need to be long to be effective: In a review of 189 studies, published in a 2025 issue of the journal Sports Medicine, researchers found that four minutes of static stretching improves flexibility in adults and there’s no additional benefit to doing more.
Myth: If you don’t stretch regularly, your muscles will shorten.
Fact: While it’s true that stretching regularly can improve your range of motion and reduce muscle stiffness, as the international panel noted, your muscles cannot physically shorten if you don’t stretch. “When you stretch, you’re not physically lengthening your muscles,” Bonoffski says. “You’re changing the brain’s ability to tolerate a greater range of motion.”
(Females bodies are uniquely flexible—here’s why that makes them strong.)
So if you don’t stretch, “that tightness you feel is more neurological in nature,” Bryant says. “It means your nervous system is in protective mode”—perhaps to prevent your muscles and joints from getting injured.
Myth: Bouncing while you hold a stretch can improve your flexibility.
Fact: Bouncing while you stretch is called ballistic stretching, and it can often be counter-productive. If you do it when your muscles are cold, for instance, it could lead to muscle strain or tendon injury. “Bouncing could cause muscles to contract, rather than relax,” says Mariam Zakhary, a sports medicine physician at Mount Sinai Hospital in New York City. “You want controlled, dynamic movements to improve flexibility.”
An exception: ballistic stretching can be helpful for highly trained athletes such as sprinters, jumpers, and other people who are used to explosive movement—that is, if they have prepared their muscles well with a proper warm up and dynamic stretching first, Bonoffski says.
Myth: Stretching before you work out will prevent sore muscles afterward.
Fact: “There’s no evidence that delayed onset muscle soreness [DOMS] is decreased because of stretching,” says Behm. DOMS, which refers to muscle discomfort and fatigue that typically develops 24 to 48 hours after vigorous exercise, is caused by microscopic tears in muscle fibers. Stretching before exercising won’t prevent that phenomenon; it’s a natural response to a hard workout.