When done right, exercise can be a true miracle drug. But if you follow the wrong advice, it’s easy to get injured. For example, the sit-up was once considered the gold standard exercise for core (the muscles of the abdominal wall), but we now know that it can make lower back pain worse.
Exercise culture is rife with such misconceptions, due to constantly evolving science and influencers sharing advice based on “anecdotes and gym lore,” said Brad Schoenfeld, professor of exercise science at Lehman College. from New York. “Once those opinions spread among the public and become entrenched, they are difficult to change.”
I asked more than a dozen fitness experts to share the myths they hear most frequently from clients and patients that they wish they could debunk.
Myth 1: You should stretch before exercise
If you’ve been to a school gym class, maybe you were told to spend a few minutes stretching before exercising. But recent research has found that stretching before exercising is ineffective at preventing injuries and can be counterproductive. This is because stretching a muscle for more than 90 seconds temporarily decreases its strength.
“You just temporarily weakened all the muscle groups you were trying to train,” said Josh Goldman, associate director of the Center for Sports Medicine at the University of California, Los Angeles School of Medicine.
If you really like the feeling of stretching before physical activity, don’t hold the stretch for too long, Goldman said.
If you want to prepare more effectively for exercise, perform a dynamic warm-up; That is, a series of active exercises that get the blood flowing and tighten the muscles a little. The expert recommends leaving stretching for another time. “I like to tell people to do them before bed,” as this gives the muscles time to recover before moving again.
Myth 2: You have to lift a lot of weight to build muscle
Schoenfeld, who studies how muscles develop, says that’s not true. A significant body of research now shows that lifting relatively light weights for, say, 30 repetitions is as effective at building muscle and strength as lifting weights that feel heavier for five to 12 repetitions. It’s a matter of personal preference.
But don’t avoid lifting more weight for fear that it will make you look “too muscular,” said Jacob Sellon, a sports medicine doctor at the Mayo Clinic. “It actually takes a lot of effort” to have Popeye’s muscles, he says. “It’s not something that happens just with typical strength training.”
Myth 3: Running hurts your knees
Fear not: Research has already debunked the idea that running increases the risk of osteoarthritis and even suggests that it may protect your knees against the disease. In fact, not moving increases the risk of developing osteoarthritis, along with age, weight and genetics.
For years, experts thought that “our knees were like tires: If your car moves a lot of miles, you wear out the tread,” Goldman explained. “That is not true, because our body is dynamic” and our joints can regenerate on their own, especially when we do physical activity regularly.
But ultimately, running can cause knee pain or injury if you overtrain, said Jordan Metzl, a sports medicine doctor at the Hospital for Special Surgery in New York. Metzl calls this “violating the rule of too many”: running too fast or too far too soon. “It increases little by little,” he said. And if you start to feel pain in your knee, go to a sports medicine expert for a check-up as soon as possible.
Myth 4: Walking is enough to keep you in good condition as you age
Walking is a fairly common exercise among older Americans for good reason: It has been shown to lower the risk of heart disease, diabetes, and some cancers, as well as the risk of premature death. And it is also very simple.
But walking isn’t enough to stay fit as you age, said Anne Brady, an associate professor of exercise science at the University of North Carolina-Greensboro. After the age of 30, muscle mass progressively decreases, so you must also focus on strength training.
“People can do daily activities with a minimal amount of cardiovascular conditioning,” he said. “But when they don’t have the strength or muscle power to do their daily activities, that’s when they lose their independence.”
Walking should be complemented with weekly 20-minute strength training sessions.
Myth 5: Mods are for beginners
Choosing to do a less demanding version of an exercise — for example, a push-up or a plank with your knees on the floor — doesn’t mean you’re weak or a novice or going backwards, said Stephanie Roth-Goldberg, a clinical social worker and therapist at New York that works with athletes. It’s a sign that you listen to your body and keep it safe.
“Our bodies need different things every day,” he says. “Modifying the exercises helps us work on posture and the mind-body connection.”
Myth 6: Runners and cyclists don’t need lower body resistance training
Amanda Katz, a certified strength and running coach in New York, says she often has to convince clients who run or cycle that they also need to do lower-body resistance training.
Pounding the pavement or hitting the pedals strengthens the lower body, but not enough to stimulate significant muscle growth, he said. A strength training regimen that includes squats, lunges, glute bridges, and pointe training can improve bone density and reduce the risk of injury, as well as make you a stronger runner or cyclist.
Myth 7: You need to walk 10,000 steps a day to be healthy
No. Exercise scientists debunked this myth years ago, but many Americans still consider it a benchmark of good health, said Cedric Bryant, president and chief scientific officer of the American Council on Exercise.
The myth dates back to the 1960s, when a Japanese watch manufacturer mass-produced a pedometer whose name translated as “10,000 step meter.” “Unfortunately, it has taken on a life of its own, because clearly the research does not support that there is anything magical about that goal,” Bryant said.
The most recent research suggests that the health benefits of walking appear to plateau at 7,500 steps, but even 4,000 steps a day can reduce the risk of dying from any cause.
Myth 8: Taking ice baths after a hard workout improves recovery
Soaking in an ice-cold tub after a hard workout can seem like a savior against injury, as it helps reduce inflammation. But this has a problem.
“Not all inflammation is bad,” Goldman said. If you soak in a cold tub after every workout, you could delay or stop the repair process.
Goldman explained that when you exercise, you create helpful inflammation by strategically straining your muscles, and as your body recovers, it gets stronger. If you want to treat a specific injury after a workout, Goldman recommends applying ice to the injury or waiting a day before taking an ice bath to give your muscles time to begin the repair process.
The same rule applies to over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs): since they are anti-inflammatories, you should only take them after training if you are treating an injury. Otherwise, you risk counteracting your training.
“Immersions in cold water are a very good tool to reduce inflammation, but you have to use it at a time when you really want to prevent inflammation and as a prescription after each workout,” Goldman recommended.
For general recovery after a workout, research suggests that saunas are safer and more effective.
Danielle Friedman is a journalist in New York and author of Let’s Get Physical: How Women Discovered Exercise and Reshaped the World. More from Danielle Friedman