Do Overweight Runners Experience More Knee Pain?

How Does BMI Affect Running-Related Injuries?

Do overweight runners have more knee pain? This comparative study was designed to determine the distribution of running injuries by location in runners with different BMIs.

Researchers merged data from 4 independent prospective studies with 2612 participants who were novice and recreational runners. The proportion of running related knee injuries out of the total number of running-related injuries were compared for normal-weight, overweight, and obese runners. A total of 571 running-related injuries were included in the analysis. Of the 571 running-related injuries, 181 were knee injuries and 390 were located in other body regions. 

The researchers found that overweight and obese runners had:

1. A lower proportion of running-related knee injuries compared to normal-weight runners

2. A higher proportion of running-related lower-leg injuries compared to normal-weight runners (lower leg injuries such as tibial stress reaction / tibial stress fractures / medial tibial stress syndrome (MTSS), also known as shin splints).

While the knee and lower-leg were found to be the two most common locations injured, overweight and obese runners may be overloading their lower-leg more and their knee less compared to normal weight-runners.

Remember the proportion of injuries does not mean the absolute number of injuries! This means that overweight and obese runners may actually experience more running-related injuries and more knee pain compared to normal-weight runners. But of the injuries that are sustained by overweight and obese runners, a smaller percentage involve the knee and a larger percentage involve the lower-leg compared to normal weight runners.

Limitations of the study:

1. There were disproportionately more overweight and obese runners who were novice runners compared to normal-weight runners. There were not enough experienced runners who were overweight or obese to stratify the analysis by experience.

This seems reasonable as more experienced runners may generally have a lower BMI, because of more exercise exposure, all else being equal. However, it is plausible that more experienced runners have built up more load tolerance and better running technique, leading to less susceptibility to running-related injuries such as knee pain.

2. Two of the four studies included self-reported injuries rather than clinical diagnoses.

However, the main findings held true regardless of whether the injuries were self-reported or clinically diagnosed so the validity was not affected.

3. Three of the four studies provided running programs, which did not allow runners to self-determine their running exposure.

Since Body Mass Index (BMI) may influence a runner’s choice of exposure and therefore total load to the knee, not having a self-determined running exposure would decrease the generalizability to the general running population.

4. Only novice and recreational runners were included in the studies.

So the results here may not be generalized to elite and experienced runners.

Closing Remarks:

Amongst novice and recreational runners, a higher BMI is associated with a smaller proportion of knee pain and greater proportion of lower-leg pain compared to a normal BMI. 

If you are experiencing knee pain while running, please contact us to schedule an appointment.

Disclaimer: This is not intended to be formal medical advice. Your individual needs should be met by the appropriate health care practitioners. Please consult with a trusted provider.

Dr. Vincent Liu, PT, DPT

Doctor of Physical Therapy

The Game Plan Physical Therapy