2. Wear the right shoes. Good-fitting, supportive shoes will help you avoid injuries as minor as blisters and as serious as tendonitis. (Check out our Beginner's Guide to Running Shoes.)
3. Seek out expert advice. If you're brand-new to exercise, it's probably a good idea to hire a personal trainer or take a fitness class, where the instructor can teach you proper form, Wenner says.
4. Warm up first. Studies can't seem to agree about whether warming up your muscles helps protect against injury. What it can do is improve your range of motion at your joints and loosen your muscles, so you're less likely to tear them. Warming up is beneficial in another way: It helps mentally prepare you for what you're doing. That's important, because being distracted and not concentrating on your workout can lead to injury.
More: 6 Strategies to Beat Workout Boredom
5. Know the difference between pain and discomfort. Exercise can be uncomfortable, but the only way to improve your fitness level is to push past the discomfort. On the other hand, exercise should never be painful, and you should never push through pain. "If you're doing an exercise and you're thinking 'I can't do this' or 'I don't feel like doing this,' then you have to push yourself harder," Wenner says. But if you're experiencing true pain, especially around your joints, you need to stop what you're doing right away. Otherwise, you're putting yourself at great risk for injury.
6. Increase intensity slowly. It's been said that you need to walk before you can run, and that's certainly true for exercise. A good rule of thumb is to increase your intensity by about 10 percent per week. Let's say that you decide to take up running. You shouldn't lace up your sneakers and head out for a jog if you've never done it before, Wenner says. Instead, start by walking a mile. Then walk 2 miles. Then jog slowly for 1/2 mile. Once that feels comfortable, you can increase your speed and distance gradually.
7. Exercise all week, not just on weekends. Weekend warrior syndrome -- when you try to squeeze a week's worth of exercise into just two days—is a recipe for injury. It's much better to aim for five days of moderate activity, even if it's broken up into brief, 10-minute workout sessions.
8 Rest after training. Your muscles need a day of recovery after you lift weights; otherwise, you could cause a sprain (in which the ligaments that connect your bones at the joints stretch or tear), or a strain (in which the muscle or tendon that connects the muscle to bone stretches or tears), or develop joint pain.
9. Know when to take a day off. "You're not going to lose your strength and fitness gains just by taking a day off," Wenner says. If you feel that you need to do something, go for a walk instead of running or heading to spin class. When your muscles are tired, they won't support your joints as well, which can lead to injury. The same rule applies when you're sick. It's okay to work out when you have a runny nose or a cough, but if the illness is below your head -- e.g., a chest cold or gastroenteritis -- postpone your workouts until you feel better. And, as a courtesy to the other gym members who need to use the equipment after you, be sure to wash your hands frequently and try to avoid touching your mouth and nose and then touching the equipment.
Adapted from the List Maker's Get-Healthy Guide: Top To-Dos For an Even Better You!