For the first time, a group of prominent running physicians has issued a Youth Running Consensus statement intended to “reduce injury and illness risk” among young runners and “promote lifelong health.” The evidence-based statement is aimed at runners 13 to 18, but also includes “opinion” about runners 12 and under.
The 22 members of the consensus group come primarily from the U.S. but also include experts from Brazil, Germany, and Italy. They began meeting in 2018 and had several in-person or virtual get-togethers in 2018 and 2019 before beginning work on their early consensus drafts. In all they reviewed 1602 scientific-medical articles on youth running.
Running, they note, has become the second most popular physical activity among boys and girls 12 to 15 in the U.S., and almost 500,000 American high school students participated in cross-country in 2018/2019. Running injuries in the group seem to be increasing, though most appear to be minor in nature, involving “strains, sprains, and apophyseal [growth plate] injuries.” More serious injuries are “far less common.”
The consensus statement includes many findings that experienced coaches, parents, doctors, and physical therapists would expect. And a few that perhaps defy conventional wisdom. For example, there is no current indication that running surface contributes to injuries. Also, there is conflicting or unclear evidence concerning shoe selection, footstrike mechanics, and muscle strength.
Published in free, full-text form by the British Journal of Sports Medicine, the 12-page statement is comprehensive and easy to read, with most key points summarized in numerous “sidebars.” It should be accessed by anyone with a strong interest in youth running.
Below is a summary of key aspects of the Youth Running Consensus Statement, followed by a brief Q/A with one of the principal authors.
Bone Health: Girls and Boys
Much of the concern in youth running focuses on young girls, apparently with good reason. The consensus finds that girls are more likely to incur a running-related injury than boys, and to lose more time to injuries. There’s “limited evidence” that girls might suffer from bone-health issues due to low calorie consumption, low BMI (less than 19.0), late and/or missing menstrual periods, and prior bone issues. Boys can also incur bone injuries due to low calorie consumption, low dairy, running more than 30 miles per week, and believing that thinness will make them faster.
As with adult runners, previous injury of any type is a strong risk factor for subsequent injury. Little is known about injury-prevention techniques, but “high intensity neuromuscular training, jumping/plyometrics, and balance training may reduce” risk of injury.
Summer Training and In-Season Training
Boys and girls who train less than eight weeks over the summer might have an increased injury risk, according to limited evidence. The same goes for a stride-rate lower than 166 steps per minute, training mainly on hills, or failing to alternate between training days of higher mileage and lower mileage. In addition, teen runners should have at least one rest day per week, 1 to 2 weeks of rest every 3 months, and 3 months of non running per year.
For boys and girls running 4 to 7 miles a day, the consensus statement recommends a daily calorie intake of about 3100 calories for boys and 2500 calories for girls. These are of course highly variable, depending on each runner’s body size and makeup.
The runners should follow a high-carbohydrate diet with about 15 percent of calories from protein and about 15 percent from fats. Within an hour or two of completing a running workout, they should consume about 300 to 350 calories of food that has a carb:protein ratio of 4:1.
Factors Relating to Long-Term Health
The consensus committee believes that young runners should receive the same longterm heart benefits that have been shown among adult runners. Rates of sudden cardiac death are low. Both girls and boys should be screened for “low energy availability,” i.e., insufficient daily calorie intake. It’s particularly important that they consume sufficient micronutrients, including calcium and Vitamin D, to “promote optimal bone health and reduce risk of bone-stress injury.”
Running for Kids 12 and Under
There is little to no good evidence about the health benefits and risks of running for youth under age 12, so the consensus group reported on “opinions of coaches and health professionals.” Most favored races of about 1 mile for early-elementary school students, 1 to 2 miles for older elementary school students, and 5K for those older than 12.
The Twin Cities Marathon has tracked medical issues among youth finishers, reporting that only 4 of 310 needed medical attention (half the rate of adult finishers.) The Students Run LA program has found that 99% of middle-school and high-school runners who completed the program were able to finish the Los Angeles Marathon without issue.
- Readiness for running should be judged by growth-development, not age.
- Young athletes might benefit from “high-impact and multidirectional” sports like basketball and soccer.
- To reduce burnout, sport specialization should be discouraged until youth have passed through puberty.
- Warning signs: BMI ≤17.5; bone mineral density Z score ≤-1.0; an untreated eating disorder; a history of bone-stress injuries; a female runner who has not reached menarche by age 16 or has had <6 menstrual periods in the last 12 months.
Q/A with Bill Roberts, MD, a Principal Author of the Consensus Statement
Q: An overarching question: Is there evidence, for the 12 to 18 population at large, that running is deleterious?
A: No, there is no evidence that running is a problem or risk for kids at any distance if they are training well and minding the store (good nutrition, adequate sleep, recovery time in the training plan). Most of the concern about kids running comes from overly concerned adults. That said, kids who train too hard or do not eat well do break down.
Q: Society today is all about empowering women/girls. Yet the consensus statement says female sex is one of the few areas of “strong evidence” for increased risk. Why?
A: The risk in girls is driven by inadequate energy intake and resulting bone stress injuries, although boys can land in the same situation if not paying attention.
Q: Given the bone questions, shouldn’t girls then be advised to run on soft surfaces?
A: I do not think surface is a big issue in bone stress and overuse injury as long as girls pay attention to their bodies and back off when pain starts. The evidence to support surface type is limited.
Q: The consensus notes that there is only “opinion” but not good evidence regarding runners age 12 and under. What is your opinion about running at this age?
A: I do not think it is a problem for under 12s to run distance as long as it is their idea and not a parent fantasy. Our Twin Cities in Motion data does not show a problem. We are hoping to continue studying the question.