Year after year, one of the most popular resolutions is to lose weight by exercising more or, for those who haven't been active in a while, it's to get back into an exercise routine.

"Physical activity and exercise shouldn't only be about losing weight; they're also key components of a healthy life," said Jason Scotti, M.D., primary care sports medicine physician of Geisinger's Orthopaedic Institute at Geisinger Wyoming Valley Medical Center. "Regular exercise can reduce your risk of several chronic conditions, including heart disease, type 2 diabetes, and some cancers."

However, if you haven't exercised in a while, you may not want to jump right into a new, rigorous fitness regimen.

"Pushing yourself too hard too soon or too frequently, you may be at a higher risk of injury or a medical emergency," Dr. Scotti said. "Cardiac events, like heart attacks, are rare during exercise, but the risk can go up if you suddenly become much more active than usual.

To begin a regimen of physical activity without getting hurt or sick, start slowly and gradually increase your level of activity. Starting this way can also make your fitness resolution more easy to maintain in the long term - you won't feel burned out right away.

"Once you establish your routine, then you can gradually build up the intensity, duration, and frequency. As your fitness abilities increase, you will be able to challenge yourself more," Dr. Scotti said.

If you want to increase your physical activity and have a chronic health condition, you may want to talk to your doctor before starting.

"You and your doctor can work together to determine if your condition limits your ability to be active in any way and, if so, create an exercise plan that matches your abilities," Dr. Scotti said.

To further prevent injury, make sure every workout begins with a warmup and ends with a cool down.

"Warming up for five to 10 minutes helps your body get ready to exercise by gradually increasing your heartrate and loosening your muscles and joints," Dr. Scotti said. Warming up can be as simple as riding an exercise bike, jumping rope, or jogging in place.

"Cooling down at the end of a workout is important too - it slowly brings your heart rate back to normal," Dr. Scotti said.

You should also incorporate stretching into your pre and post-workout plan - stretching can increase your flexibility and possibly prevent injury. You should stretch after you warm up and again after you cool down.

If you're unsure about getting active or increasing your current level of physical activity because you're afraid of getting hurt, it's important to know that moderate-intensity aerobic activity, such as brisk walking, is considered generally safe for most people.

"The bottom line when it comes to physical activity is that its health benefits far outweigh the risk of getting hurt," Dr. Scotti said.