Saturday, May 25, 2013

Unwanted Weight Gain: A Secondary Effect of Knee Injuries

There is little argument that weight gain and obesity is a major concern for today’s youth. The data all point to many of today’s children and adolescents experiencing an unhealthy body weight. The fact that overweight youth tend to become obese adults points to a growing health problem. Increasing physical activity is one strategy to combat excessive weight gain. In particular, several studies show that those involved in youth sports tend to have a healthier body weight and tend to be more active and fit as adults. Unfortunately, those who play sports are also at risk of injury. Researchers at the Cincinnati Children’s Hospital found that female athletes who suffer a knee injury gain significantly more weight that uninjured players. The researchers argue that this can be avoided and an ounce of prevention can prevent a pound of weight gain.

The researchers tracked a large group of young female athletes over the course of several years. The subjects included in this study were 352 young female athletes. Most played basketball but a large number were soccer players. The athletes ranged in age from 11 to 15 years. These girls were part of a long-term study on injuries in female athletes. They all underwent and initial medical examinations including a knee exam. Each had at least on yearly follow-up exam and some had up to three.

During the course of the study, 71 players experienced a knee injury (20%). The investigators found that within one year, those players who suffered a knee injury gained significantly more body weight than those who were uninjured. This was the case when weight gain was adjusted for expected growth and maturation of the players. Unfortunately, the weight gain was associated with an increase in body fat percentage.

It’s clear that the increase weight gain was due primarily to decreased physical activity. Nearly 60% of those injured stopped playing completely during the year following injury. The remainder had to take some time off during recovery and rehabilitation from their injury.

Over the past 30 years, pediatric obesity rates in the USA have more than doubled. There is no doubt that participating in youth sports can help stem this increasing problem in today’s youth. However, sustaining a knee injury seems to limit and discourage participation. In some cases may cause the player to quit playing. This in turn can lead to inactivity and weight gain. In addition, knee injuries and obesity are two major contributors to knee osteoarthritis in adults. Thus, sustaining a knee injury while playing youth sports could be a double-edged sword, so to speak.

So could the prevention of obesity, that is participation in youth sports, contribute to the problem? The researchers argue that it is unrealistic to think that we can completely eliminate knee injuries in youth sports. However, appropriate training for these sports can reduce the risk and incidence of injuries. In turn, it could help prevent unwanted weight gain.

They state that “regular participation in appropriately designed and sensibly progressed preparatory conditioning programmes beginning during preadolescence may help to reduce the likelihood of a sports-related knee injury in young athletes and the resultant unhealthy weight gain.” In this case, an ounce of prevention may literally avoid a pound of problem. Focusing on injury prevention can keep players physically active while reducing the risk of injury.

This research group has long advocated the use of of neuromuscular training as a key component of injury prevention. They have published many studies showing that injury prevention programs such as the FIFA 11+ can lower the risk of knee injuries in females participating in sports programs. In addition, these programs can improve performance in competitive athletes. Numerous other studies back this up.

Using youth sports, in particular soccer, as part of a comprehensive physical activity program can have numerous health benefits. These include body weight management, improved physical fitness, increased muscular strength as well as knowledge and understanding of how exercise and nutrition contribute to health and performance.


Myer GD, Faigenbaum AD, Foss KB, Xu Y, Khoury J, Dolan LM, McCambridge TM, Hewett TE (2013) Injury initiates unfavourable weight gain and obesity markers in youth. British Journal of Sports Medicine, doi:10.1136/bjsports-2012-091988