Most of us have been taught from a young age that failing to stretch before or after exercising is akin to a mortal sin. Skip your stretching routine, the thinking goes, and you will be more prone to injury, soreness and a generally worse workout.
But is this wisdom backed by science? And do you really need to stretch before and after every exercise? “The simplest way to answer that question would be no,” says Dr Samantha Smith, an assistant professor of clinical orthopaedics and rehabilitation at the Yale School of Medicine.
But the longer answer, experts say, is that it depends on the type of workout you’re doing as well as your fitness goals. Here’s why.
What does the research show?
If you’re about to do an exercise that doesn’t involve a large range of motion, such as a jog for a few miles at a relatively steady pace, you don’t need to stretch beforehand, said David Behm, a research professor in sports science at Memorial University of Newfoundland. (There are many different types of stretching, but for this story, we’re talking about static stretching, where you hold still in a position to lengthen a muscle.)
In such a case, a simple warm-up with dynamic movements – like lunges, squats, butt-kicks and high knees – will adequately prepare your body.
While some evidence is conflicting, the majority of research also suggests that static stretching has no effect on – or may even hinder – your performance during strength and power training. (Power training involves performing moves like jumps or explosive lifts to work on both speed and strength.)
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Strength exercises involving large movements, like squats or bench presses, will lengthen muscles in the same way that stretching does, Behm says. So stretching before a lifting session would not improve your performance (or be a great use of your time). And, he said, stretching can slightly fatigue your muscles and tendons, so if you stretch your quads and glutes before you do squats, for example, that might actually hinder your workout.
Many people stretch before working out to reduce their risk of injury, but there’s a lot of conflicting evidence on that topic as well, Behm says. For instance, he and his colleagues found in a 2021 review that while static stretching before exercise didn’t always decrease the risk of injury, it did reduce muscle and tendon injuries when done before exercises requiring agility and explosive movements, like sprinting, jumping or pivoting.
Ideal preparation for exercise comes in two steps, says Eduardo De Souza, an associate professor of health sciences and human performance at the University of Tampa. First, you should raise your body temperature with a warm-up – light jogging, jump rope or light cycling, for example. “And then you do a rehearsal of the movements for what comes next.”
That means dynamic movements that stretch your muscles’ full range of motion – think walking lunges or arm circles.
What about stretching after a workout?
Many people stretch after a workout because they think it will aid their recovery and minimise soreness, Behm says. But “the literature is very mixed on that” too, Dr Smith adds. When it comes to stretching after lifting weights to prevent muscle soreness, for example, “there have been studies that have shown a positive benefit and studies that have shown no benefit,” she says. Likewise, in a 2021 review, researchers found no evidence that static stretching after a workout sped recovery (or did anything useful at all). That said, Dr Smith hasn’t seen any evidence that stretching as part of a cool-down after a workout is harmful.
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In another 2021 review, Behm and his team found that stretching to minimise soreness only works if you have a consistent stretching routine, separate from other workouts, that you did regularly before you started doing strenuous exercise. These stretches should last for 30 to 60 seconds for each muscle group, and be performed at least twice a week.
After a workout you should do a proper cool-down, and stretching is one way to do that, De Souza says – as is foam rolling or walking. Although, he says, there’s not enough research to determine what cool-down method will make you feel the best after a workout.
When should you stretch?
If you would like to improve your flexibility or mobility, then stretching various muscle groups for about 30 to 60 seconds each day can help with that, Dr Smith says. It can also be beneficial in ways you may have never even realised.
People don’t often think of stretching for flexibility as its own kind of exercise or workout, Dr Smith says, but making a point to add a separate stretching routine to your weekly workout regimen can help you reach your flexibility goals.
Stretching can also help loosen tight muscles. But be careful, Dr Smith says since “an injured muscle or a weak muscle is frequently a tight muscle.” If a muscle feels tight and painful, that’s a sign that it could be injured, so you should see a healthcare provider before you start stretching it.
Other benefits of regular stretching include improved balance as well as help with joint and muscle pain, Behm says.
But rather than focusing on whether or not to stretch, Dr Smith says, it’s important to look at the bigger picture of physical fitness, “which is that being strong, having good balance, having good co-ordination” are all important goals to strive for with various types of exercise. Stretching can be a part of that, but if it doesn’t fit in with your schedule or goals, you don’t have to force it. – This article originally appeared in The New York Times