Let’s face it, we wouldn’t be able to do much without them. But it can be easy to ignore or de-prioritise something until it becomes an overt issue … an injury (overt break or ‘just’ a stress fracture) that takes you out of training and competition for weeks or months, or osteoporosis at a young or old age.
But bone health really is something to have on your radar as an athlete. Especially as there are day to day factors to be aware of that may help support your bones for the short and long term.
What are strong healthy bones?
A bit like tendons and ligaments there are two components required for strong bones: density and architecture. In other words, a high bone mineral density (BMD) organised within a strong mesh that can take knocks from all angles.
Bone mass peaks by our early 30’s. After this, we cannot 100% compensate for age related loss. This means:
a) the more bone mass we can accrue by the time we are 30 the better, so we still have ‘enough’ left when we are old; and
b) the more we can do to preserve our bone mass after this age, the better; AND
c) we certainly don’t want to be doing things that reduce our bone mass and strength before we are 30 … not only exposing ourself to the consequences of weak bones (fractures, osteoporosis) as young as our 20’s, but also to minimise how much we lose the bone mass battle as we head to our 40’s and beyond!
So, how do we get and keep strong healthy bones?
Mechanical loading and diet!
Like muscle, the more we (appropriately) stress a bone with mechanical load in training, the stronger it will get IF diet provides the energy and building blocks to do so. If we don’t provide the right diet, then the training stress can result in damage, loss of bone strength, and injury.
From a training perspective, the implication of this is that sports with mechanical loading potentiate strong bones. So, strength based sports, running (at least leg bone strength) and so on. And on the flipside, sports without significant mechanical loading, e.g. cycling, may be at risk of weaker bones unless strength or impact based training is actively included.
Now, the dietary component. Bones can only build and maintain strength with a diet that provides sufficient energy and building blocks to do so. The key components of this are a diet with:
Sufficient calories
Sufficient protein
Sufficient minerals, in particular: Calcium, magnesium, phosphorous, potassium, fluoride, silicon, sodium
Sufficient vitamins, in particular: Vitamin D, vitamin K
Athletes or highly active individuals may be at higher risk of insufficiency in one or more of these elements than the general population because:
Endurance athletes who burn high amounts of calories daily, or sports where for aesthetics or short term performance a very light bodyweight is maintained are at higher risk of Low Energy Availability (LEA), whereby they are not taking in sufficient calories to meet their needs
Of these, as a result of the low food intake, some of these athletes may also not be obtaining sufficient vitamins and minerals to support bone health
Calcium and sodium are lost in sweat
Athletes may be on low fat diets due to their high protein and carbohydrate needs, and so lacking in sufficient vitamin K
So, what can we do nutritionally?
Minimise periods of Low Energy Availability. There may be periods where calorie intake needs to be lower than optimal, but aim to PERIODISE nutrition so that these periods are followed by a period of higher calorie intake to enable the body to function effectively. The extent to which this mitigates the risk of the low energy periods is not clear, but it is certainly going to be more effective than continual low energy availability.
Ensure foods high in each of the vitamins and minerals outlined above are included in the diet, in particular during periods of heavy training. And, if possible, have regular blood tests (bi-annual or annual, depending on the initial results) to ensure insufficiency and deficiency is avoided.
If you live in the Northern Hemisphere in October-March, or do not see at least 30 mins safe sun exposure over a large proportion of your skin in the summer months or Southern Hemisphere, consider supplementing with 2,000 IU vitamin D3 daily. This vitamin is made in the skin in response to appropriate sunlight, so if we don’t get that sunlight we don’t get vitamin D3.
Anything else?
For women, oestrogen exerts a protective effect on bone mineral density. Therefore post menopause, women can see an acceleration in bone losses. It is therefore of increasing importance after this age to match training and nutrition to support bone health, and have regular checks of bone density to identify early signs of weakness or osteoporosis.
Read more …
Sale, C., & Elliot-Sale, K.J. (2019). Nutrition and Athlete Bone Health. Sports Medicine, 49 (Suppl 2), S139 -0 S151
https://www.sportsdietitians.com.au/factsheets/fuelling-recovery/bone-health/
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