A new study provides the first research-backed injury-prevention advice for beginning runners: Start very, very slowly. And if you are substantially overweight, consider losing weight first.
Every runner worries about injuries. With time, most learn how to bob and weave through the semi-regular muscle soreness, and the less-frequent-but-more-worrisome sharp pains.

Beginning runners, however, don't have the experience to cope. Just when they're getting started on a program intended to improve their health and fitness, an injury often puts them on the sidelines. They might never get going again.

That’s why a group of Danish researchers organized the DANO-RUN project several years ago: They wanted to find ways to help novice runners avoid injury.

Their newest report, published in the International Journal of Sports Physical Therapy, is the first study to focus on the first three weeks of training among beginning runners. It found that individuals with a body mass index (BMI) greater than 30 have a significantly increased risk of injury, and that the risk rises dramatically when these individuals run more than two miles in their first week.

The study included 749 beginning runners (average age: mid-30s) who were all given the same pair of running shoes, but were not told how to train. As a result, in their first seven days, they ran anywhere from 400 meters to 18 miles. For statistical analysis, the researchers placed them into three groups: less than 2 miles, 2 to 4 miles, and 4+ miles. They also did correlations with BMI.

The results showed that heavier runners had more injuries, and that those with a BMI over 30 could reduce their injury risk by 50 percent if they ran no more than two miles in their first week of training. (Avoid being sidelined by a preventable injury with Runner’s World guide to The Most Common Walking and Running Injuries.)

"Individuals with a BMI greater than 30 may be well advised to refrain from running more than 3 kilometers during their first week," the authors concluded.

Another approach: Heavy beginners might focus on losing some weight before they begin a running program. "This may also be an injury-reducing approach," the researchers wrote.

While 2 miles per week seems low to experienced runners, it could fit well into the popular run-walk beginning programs advocated by Runner’s World and other groups. The DANO-RUN results also emphasize something that’s easy to forget: Beginning running programs, especially for the overweight, should start at a very low level of running, and progress very gradually.

Another implication of the study: It might be wise for overweight beginners to start their fitness program with a month or two of brisk walking, and a diet. The legs and joints will gain strength, and any weight lost will make the transition to running go smoother.

Check out this video about how to properly tie your running shoes.