MYTH #3 Most exercise is hard on your back
FACT Researchers from Samsung Medical Center in Korea found that working out at least three times a week actually reduced the risk for developing chronic back pain by 43 percent. Exercise strengthens your back muscles and increases blood flow to the disks, helping them withstand daily strain. Hitting the gym regularly also keeps your waistline in check, which has a huge payoff for your back: A study in the journal Spine revealed that overweight people were nearly three times as likely to go to the hospital with a back injury than those at a healthy weight. Even as little as 5 or 10 extra pounds can put stress on your spine, increasing your risk of injury. Opt for low-impact aerobic exercise, such as walking, swimming, or using the elliptical machine, to strengthen your back without putting excess pressure on your disks or joints.

Still, it's important not to do too much. Overexerting yourself—by lifting too-heavy weights or stretching past the point of comfort—is a surefire way to injure your back. To protect yourself while working out: Warm up with at least 15 minutes of light cardio to increase blood flow to back muscles. Next, observe your form in the mirror when lifting weights. Your back should always be straight, whether you're working your biceps or your legs. Finally, avoid overstretching or bouncing; those movements jar the spine and muscles.