Running is a powerful fitness tool.
It leaves few of the body's systems untouched, simultaneously building cardiovascular endurance, strengthening leg muscles and burning calories. Running regularly can keep you fit, lean and happy. That's right! Running spurs the release of endorphins, chemicals in your brain linked to happiness.
So if the question is "Should I run?" The answer seems to be a resounding "Yes!"
Things get confusing from there. When you should run, how often you should run, where you should do your training are all dependent on your goals and fitness level.
While some marathoners regularly run more than 100 miles a week at head-turning speed, other novice runners cover 20 miles a week or less at slower paces. With such a wide range of runners and training plans, plenty of myths and misconceptions surround this seemingly simple activity.
Here, we separate the fact from fiction.
While certain runners do suffer injuries to the ligaments, tendons and cartilage of the hip, knee and ankle joints, running may actually prevent or treat arthritis.
Benjamin Ebert, M.D., Ph.D.
MYTH #1: Running in the Cold Will Hurt My Lungs
People who've never run in very cold conditions, whether because they're new to running or because they live in warmer climates, often express concern that their lungs will freeze if they run in freezing temperatures.
This seems to stem from the fact that the increased rate of breathing during running can be uncomfortable in any setting — especially among less-conditioned novice runners — and because cold weather can, in fact, exacerbate respiratory problems in those with pre-existing maladies such as exercise-induced asthma.
Nevertheless, concerns about physical damage to the lungs and respiratory tract are unfounded.
"The lungs are very well-protected," said Cathy Fieseler, a physician and ultra-marathoner. When you breathe in cold air, the warming process begins immediately. The air you breathe in is warmed first by the tissues in your nose, then by mucous that lines your respiratory tract, and finally by the trachea, Fieseler says.
So unless it's too cold to be safely outside for other reasons — a high risk of frostbite, let's say — you have nothing to worry about.
MYTH #2: Running Will Destroy My Knees
The myth that running can lead to arthritis or "bad knees" persists to a great degree among sedentary observers, who note when their running friends complain of aches and pains.
Naturally, some runners are concerned there may be truth in this belief. While certain runners do suffer injuries to the ligaments, tendons and cartilage of the hip, knee and ankle joints, running may actually prevent or treat arthritis, says Benjamin Ebert, M.D., contributor to "Runner's World."
Dr. Ebert says that the way your joints adapt to running can stall the degeneration associated with a sedentary lifestyle.
MYTH #3: Lactic Acid Makes It Harder to Run
If you've been running for more than a month or two and have been doing your homework, you've almost certainly learned about lactic acid. More to the point, you've probably seen or heard it demonized.
The folklore goes something like this: Lactic acid is produced in response to intense, anaerobic running, such as all-out sprinting or charging up a hill. As a result, muscle acidity rises, and consequently, muscle work grinds to a halt. Lactic acid then pools in your legs, causing soreness and tightness, unless it's cleared with massage or foam rolling.
The truth, however, is more nuanced. Lactic acid, as such, does not even exist in the body, says Matt Fitzgerald, a senior editor for "Triathlete" magazine. Instead, the body synthesizes lactate, the dissociated form of the acid.
So although the concentration of hydrogen ions in muscle does rise during intense running, the hydrogen ions do not come from lactic acid. And even if they did, muscle pH does not drop low enough to interfere with muscle functioning.
MYTH #4: In A Marathon, I Should Fear "The Wall"
Just as shorter-distance competitors hear about the evils of lactic acid early and often, aspiring marathoners are conditioned by their peers to fear "the wall."
The 26.2-mile marathon, so the story goes, doesn't really begin until 20 miles in, when your body runs out of stored glycogen and has to turn to stored fat for fuel. If you pace yourself poorly or if you don't practice long, slow "fat-burning" runs in training, you'll invariably hit the wall sometime around 20 miles, then shuffle painfully to the finish, demoralized and far off your goal.
While it's true that poor preparation can lead to hitting the wall— or "bonking," as many runners put it — it's far from inevitable. Fitzgerald outlines several ways to stave off the feared late-race monster.
"If you're hitting the wall at 40 miles per week, aim for 45 or 50," he says. "Research has shown that weekly running volume is one of the best predictors of marathon performance — an even better predictor than the distance of the longest run."
Fitzgerald also suggests doing at least one run during your training buildup in which you spend as much time on your feet as you expect it will take to finish the marathon, even if you have to include walking breaks.
Finally, he emphasizes the critical importance of smart pacing.
"It's best to start a little slower than your goal pace. Listen to your body and stay comfortable as long as you can, and then push hard in the last six or eight miles. Once you've completed a marathon without hitting the wall, then you can race more aggressively in your next one."