These 4 outdoor workout myths aren't doing you any favors

We asked University of Texas’s Exercise Science program director, Hirofumi Tanaka, Ph.D., to help us debunk some of the biggest outdoor workout myths (you know, while the weather is still on our side). Here, four things you need to stop believing ASAP.

MYTH: STRETCHING PREVENTS INJURIES

“Probably one of biggest myths people still believe is that stretching reduces injuries,” says Tanaka. But it turns out this widely held fitness tenant is actually stretching the truth (yes, pun intended). Even though Tanaka says stretching tendons before a big outdoor run might seem logical, studies show that it doesn’t actually have a positive effect. A 2011 study by the American Academy of Orthopaedic Surgeons found that stretching before a run had no impact on injuries. And a 2003 Military Medical Journal study which followed military recruits doing rigorous outdoor training programs had similar results. In fact, Tanaka warns that some athletes might actually want to avoid stretching before games for performance reasons. “Tendons are like springs,” he says. “If the spring stretches out, your jump height and sprinting activity goes down, which is actually detrimental.” Instead, warm up with a brisk walk or slow jog, or try some of these mobility exercises.

MYTH: IT’S BETTER TO RUN ON A SOFT SURFACE

While running outside, you may have noticed many people opt for a softer running trail over a paved road. That's because it's a common belief that softer surfaces are better for joints, Tanaka says. “The funky thing is that there’s no evidence for that,” he says. Tanaka actually warns runners to be extra vigilant when they’re on softer surfaces, since they tend to be more irregular than pavement, and may lead to falls and twisted ankles. “It could actually be worse for you!”

MYTH: YOU BURN MORE CALORIES IN THE HEAT

The next time you consider scheduling your workout during a heatwave (for those extra calorie-torching benefits), think again. According to Tanaka, a three-mile run in 60-degree weather will burn virtually the same number of calories as a three-mile run in 85 degrees. “The energy expenditure is usually pretty similar because you are doing the same amount of work,” he says. “The only difference is if you’re exercising in heat for a prolonged period of time.” If you are exercising in higher temps for 45 to 60 minutes or more, you might experience a cardiovascular drift, which causes a major increase of sweat and climbing of your heart rate. At this point, Tanaka says you might have a 5 to 10% increase in how many calories you’re burning, but the increase will be slight. Exercising in extreme heat can also be dangerous—make sure you take these precautions before venturing out in the blazing sun.

MYTH: WATER’S ENOUGH TO KEEP YOU HYDRATED FOR ALL OUTDOOR WORKOUTS

“It really depends on how long an exercise session you’re doing,” Tanaka says. If you’re going for a run-of-the-mill 5K in the park, then sure, water’s got your hydration needs covered. But for more strenuous activities, like triathlons or other long-distance endurance events in the summer heat, you’re going to need to add a little something extra to your H20.

“What happens in those events is that you’re sweating like crazy and losing salt and electrolytes,” Tanaka explains. To make matters worse, the water you’re already chugging is diluting salt and electrolyte levels even more, which could lead to hyponatremia (low sodium levels which cause your cells to swell).To avoid this, if you head out for a rigorous workout, make sure you also take salts and electrolytes to stay fully, safely hydrated.