Stress Fracture Risk Rises in Winter – Here’s How to Avoid Them
During winter, the days are shorter, we cover our skin more and we’re less likely to spend time outdoors – severely limiting our exposure to sunlight.
While you might be missing the feeling of warmth on your skin, your body is missing something far more vital: vitamin D.
How does a lack of vitamin D increase risk of stress fractures?
Your bones are constantly shedding old tissue and replenishing it with fresh, new growth. This new bone is hardened by calcium, and for calcium to be metabolised, you need vitamin D – which is produced through a chemical reaction which occurs when radiation from the sun hits your skin.
If you don’t get enough sun, your vitamin D levels will drop, reducing the amount of calcium your body absorbs. Without enough calcium, your bones are unable to provide enough fresh growth, resulting in a reduction in bone density and increased risk of stress fractures.
Stress fractures are caused by repetitive loading of a specific area of bone until it forms a small crack. They’re more common in people who do high impact exercises such as running, which increase the rate that bones shed their old tissue.
During winter, it’s more likely that your body won’t be able to produce enough new bone to keep up with the increased rate of bone regeneration caused by high impact exercise.
The rate that bone is replenished also naturally slows as we age, which leads to weaker bones in later life which must be managed through controlled loading. Vitamin D deficiency is common in elderly people and becomes critical over winter.
How can I avoid stress fractures over winter?
High impact activities are still important over winter for their stimulating effect on bone regeneration, but you need to make sure you don’t increase the intensity of your exercise too quickly otherwise you could overload your bones.
The balance between loading and overloading your bones is very delicate and specific to your muscle mass, BMI and diet. This time of year, it’s a good idea to consult with a physiotherapist to look at any imbalances that may be causing you to overload certain areas when doing high impact activity, especially if you’re starting a new exercise routine.
You should also up your calcium intake as your body is likely to be absorbing less than usual. Dairy foods, leafy greens (except spinach), soya beans, nuts and tofu are all great sources of calcium.
What does a stress fracture feel like?
A stress fracture presents as a deep, boney pain which is painful to the touch and increases when the affected area bears weight. It is more common in the lower limbs, as they are subjected to the most load, and is particularly common in the shins.
Stress fractures can be diagnosed with an MRI or X-ray, but can take up to three weeks to be visible on an x-ray. It is better to intervene immediately after symptoms are felt than wait for results.
How do I get more vitamin D in winter?
Unlike most vitamins, vitamin D is barely present in food. Outside of exposure to sunlight, the best sources of vitamin D are oily fish, beef liver, eggs and staple foods which have been fortified.
Studies are mixed on the effectiveness of vitamin D supplements, but the risk of toxicity is very low, so there’s no harm in taking them at the recommended doses – with the usual caveat to check with your doctor first if you have certain medical conditions, are pregnant or breastfeeding.
Worried about winter stress fractures? Get in touch with us
Bones are tricky. Both underloading them and overloading them can result in a loss of density, making it very hard to know how to improve yours without specialist help.
At Physio London, we can prescribe exercises specific to your age, activity level and general health to improve bone density without increasing risk of stress fractures. Get in touch now by calling 0207 093 3499 or emailing firstname.lastname@example.org.
BSc MCSP HCPC Sports and Spinal Physiotherapist