Fitness myths are many, and they are persistent, like mosquitoes on a late-summer night.
So let's take a moment to clear up some of the most common fitness myths:
1. A higher number on the scale means you're getting fatter: It depends where those pounds are coming from: fat or muscle. "The difference is the density," said Shirley Archer, a fitness and wellness educator with the American Council on Exercise.
"A pound of muscle takes up less space than a pound of fat. That's why it's possible to become leaner and healthier while at the same time gaining weight."
2. Lifting weights makes women bulky: "First of all, it requires very intensive training that most people won't do, like pyramid training," said Victor Ibrahim, a team doctor for D.C. United.
Pyramid training is a system of overloading muscles, working them to exhaustion.
Secondly, Ibrahim said, most women lack the testosterone levels to build bulging muscles.
3. When you stop weight training, muscles turn into fat: "Muscle and fat are two different types of tissue," said Ed Ingebretsen, an American College of Sports Medicine-certified personal trainer.
When you stop training, you lose muscle mass, which in turn slows your metabolism. That can cause weight gain.
4. Running on a treadmill is better for joints than running outside: "Unless it's a high-quality, extra-shock-absorbing treadmill," Ibrahim said, it's not going to make much of a difference.
The super shock-absorbing treadmills are not likely to be found in normal gyms.
5. Moderate aerobic work puts you in the ideal fat-burning zone: "Generally, the harder you work, the more fat you burn," Archer said.
But before you can work at those most intense levels -- i.e. anaerobically -- you have to build up to it.
In other words, walk before you run and run before you sprint -- pushing the body progressively.
6. As long as you exercise you can eat anything you want: "Individual metabolism determines how many calories we burn at rest and while we exercise," Ingebretsen said.
"If we eat more calories than we burn on a consistent basis, our bodies will accumulate these extra calories as fat regardless of the amount of exercise," he said.
7. Machines are safer than free weights: Machines are not designed for all body types. There are only so many ways you can adjust the settings.
"Machines are kind of averaged out," Ibrahim said.
Free weights can be adapted more easily. But form, alignment and set-up are important for both free weights and machines.
8. If you don't sweat, you're not working: "Sweating is not always related to heart rate, which is the best measure of exercise capacity," Ibrahim said.
Sweat is just the body's way to regulate body temperature and some of us just run hotter than others.
9. Fat can be spot-reduced: Fat reduction -- in the midsection and elsewhere -- will happen with a combination of healthy eating, cardio and strength work, Archer said. You don't get to pick one body part or another.
The 1,000 crunches won't reveal the six-pack abs unless you also focus on healthy eating and some form of cardio-respiratory exertion.
10. Stretching before exercise improves performance: "You might even injure yourself if you just jump out of a chair and start stretching," Archer said.
Also, there is some indication that muscles won't produce as much force or "fire" as efficiently if the tendons are loose, Ibrahim said.
Many people, especially women, are hyper-flexible and should consider focusing on building muscle to stabilize joints rather than stretching.
It's best to stretch after working out, as muscles and connective tissue are warmed up and more receptive to "lengthening," Archer said.
She recommends slow and deliberate stretches and says to breathe deeply, hold a stretch for 10 to 15 seconds and repeat.
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