MEGAN FLYNN, PT & DPT.
As runners, we put a lot of stress on our body in many ways – physically, mentally,
emotionally…you name it! Unfortunately, this tends to result in injuries. And bone stress injuries are always close to the top of that list.
A recent study from the National Institutes of Health showed that while most competitive athletes tend to have a higher bone mineral density (BMD), distance runners actually have a BMD similar to that of non-active individuals. In fact, they showed that eumenorrheic female athletes have a spinal BMD of 5-15% below non-active individuals! With a lower BMD, runners tend to be at a greater risk for these bone stress injuries.
So what can be done to prevent this type of injury?
One factor that can be controlled and modified is the amount of calcium being consumed. The recommended daily intake for calcium is 1000mg/day (1200mg for those over 50 years old). Many people do not consume an adequate amount of calcium from diet alone and need calcium supplements to account for the deficit.
However, like many supplements, there are variables that can affect how much you actually absorb. One way to optimize calcium absorption is to take no more than 500mg at a time. For instance, if you are taking 1000mg of calcium a day, it is best to split it up and take 500mg in the morning and 500mg in the evening. It’s even better to take the calcium supplements with food to further maximize absorption (so, take one with breakfast and one with dinner). You can also take a vitamin D supplement with your calcium. Vitamin D plays an important role as it promotes the absorption of calcium during digestion for bone growth and remodeling.
On the flip side, there are certain foods and vitamins that interact with calcium in a negative way–hindering the absorption of calcium. Avoid taking your calcium supplements with these foods and vitamins:
- Caffeinated coffee and soda
- High-salt foods
- Iron supplement
- Antibiotics
- Magnesium supplements
- Zinc supplements
At the end of the day, it’s best to get your daily calcium from your diet. However, if this is an inadequate amount, a calcium supplement should be considered after consulting with your doctor or dietician.
Sources: Winters-Stone, Kerri M., Snow, Christine M. (2004) “One Year of Oral Calcium Supplementation Maintains Cortical Bone Density in Young Adult Female Distance Runners.” International Journal of Sports Nutrition and Exercise Metabolism, 14(7-17). National Institutes of Health: Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/