Stress fractures are tiny cracks in a bone, like in the foot or even in the leg, caused by repeated strain in that area. They tend to occur more commonly in the weight-bearing bones of the foot or lower leg, and typically affects those with a lower bone mineral density. What is bone mineral density, you may ask? Before we go any further, there are some key concepts to understand:
What is bone mineral density?
Bone is alive! It is constantly building (forming) and breaking down (resorption) through a process called bone remodeling. When resorption is happening faster than formation, bone will be lost.
Bone mineral density refers to the number of minerals (calcium and phosphorus), this is usually per unit of bone. The lower your bone mineral density, the higher your risk for other health-related issues such as osteoporosis and stress fractures. The only way to get an accurate picture of your bone mineral density is by using a machine called dual-energy x-ray absorptiometry.
How are stress fractures and bone mineral density connected?
If your bone mineral density is low, you will have weaker bones that are more prone to developing stress fractures. Now if you add into this the fact that you are exercising, especially if the intensity is high every single training session, you would be increasing your risk even further for stress fractures. So, as you get older, it becomes more and more important to get a bone mineral density test done to manage your risk.
With more people taking up running during the lockdown, it has become even more pivotal to be aware of your risks and take preventative measures to reduce the prospects of stress fractures. This is especially important for those who switched from the treadmill to road running to stay fit, this can increase chances of stress fractures due to change of surface and/or not using proper running shoes with poor shock-absorbing abilities.
The most common symptoms of a stress fracture are:
- Experiencing pain during a run that gets worse over time
- A sharp pain coming from a bony area, it might feel tender to touch
- Swelling on the top of the foot or on the outside of the ankle
How can I optimise my bone mineral density?
The good news is that nutrition and lifestyle choices can help support your bone mineral density, reducing the risk of stress fractures. Here are our top tips:
Get enough calcium:
Think dairy, green leafy vegetables, tofu and calcium fortified plant based milks.
Don’t forget about vitamin D:
Get out into the sun daily if possible, and include vitamin D rich foods such as egg yolks and oily fish. And don’t forget a supplement in winter.
Vitamin K is an important tool:
Choose dark green leafy vegetables such as spinach, broccoli, and kale.
Maintain a healthy weight:
Excessive or very quick weight loss can result in some loss of bone mass – so stay away from those crash diets! Being underweight (especially in women) can also lead to low bone mineral density, so keep a healthy weight.
Don’t skip the weight-bearing exercises:
Hiking, weight training, jogging – this is any exercise that forces you to work against gravity to improve bone mineral density. Word of caution for those doing long runs or ultrarunning, A study of 1212 ultrarunners returned the following results:
- 3.7 percent reported having a stress fracture:
– 48 percent of stress fractures are in the feet.
– Stress fractures among ultrarunners are less than in nonultrarunners.
So, remember that supporting your bone mineral density is only one part of the equation – including enough rest and recovery, wearing supporting footwear, and increasing the intensity of your training slowly can also go a long way in reducing your stress fracture risk!