Bone stress injuries make up to 20% of sport injuries
and is a common reason athletes end up at our clinic. A stress fracture can put a stop to heavy training for months at a time, and is often a symptom of a bigger problem which has led to the loss of bone density. This can result in short term issues such as stress fractures, and long term such as osteoporosis. So, what can you do to help prevent them?
Causes of bone density loss include poor nutrition,
lack of physical activity, hormonal and genetics. Genetics is out of our control! And athletes usually take care of the physical activity part, as long as their training includes sessions that load the skeleton, or works against gravity like running or strength training which has been shown to be protective for bone density. So why should athletes worry? The answer is nutrition related, because without sound nutrition, the benefits of exercise on your bone strength can be reduced or lost. The two biggest nutrition related factors that relate to bone health are calcium, and adequate overall energy intake. Both are important so we are covering them in 2 separate blog articles. First up is calcium.
Like muscle, bones are constantly being broken down and rebuilt. The main component of bone is calcium, for this reason dietary calcium is important for bone health. We reach peak bone density in our mid 20’s. Getting enough calcium in your diet prior to this is important for your bones to reach peak bone mineral density, and after it is important to maintain it.
After the mid 20’s bone density gradually decreases, with females experiencing more loss due to pregnancy, breastfeeding and menopause.
The recommended dietary intake of calcium for adolescents between the ages 12-18 is about 1300mg. And both men and women up to the age of 50 need about 1000mg. So what foods do we need to include to get enough? Our first go to is dairy foods.
Studies have shown that with each additional cup of skim milk consumed per day stress fracture risk is decreased by 62%, and a diet high in dairy and low in fat is associated with 68% reduction in risk (Nieves, 2010).
A diet that contains 1300mg of calcium might look like this: –
Breakfast : High fibre cereal (E.g.: Sustain, Fibre Plus or Just right) or Weetbix with 1 cup low fat milk and ½ to 1 cup fresh, tinned or frozen fruit
Morning tea: Skim flat white and a banana
Lunch: 1 sandwich (whole meal/grainy bread) with 20-30g chicken, slice of cheese and salad
Afternoon tea: Tub of low fat yoghurt and a handful of almonds
Dinner: 100g Serve of fish, 1 potato and 2 cups of steamed vegetables
Supper: 1 cup of diced fruit with a big scoop of natural yoghurt
Other nutrients important for bone health include: –
- Vitamin D is important for the absorption of calcium and phosphorus from the gut. Our main source of vitamin D is exposure to the sun. Athletes who train inside, or who cover up a lot when outside may be at risk of deficiency.
- Phosphorus is important for mineralising bone. It is found in most foods that contain high quality protein (meat, chicken, fish, dairy, nuts, eggs) and deficiency is rare.
Are you getting enough?
So, what if you don’t drink cow’s milk?
Soy milk, if calcium fortified, is a suitable alternative. Other “milks” such as rice or almond milk need to check for adequate fortification with calcium as they can be quite low, even when calcium fortified. Other foods that contain calcium can be used to boost your intake (fish with bones, some nuts and seeds, beans and some vegetables, tofu etc.).
Pop in and see us if you need help looking after your bones!
Nieves, J. W., Melsop, K., Curtis, M et al. (2010) Nutritional factors that influence change in bone density and stress fracture risk among young female cross-country runners. PM & R. Vol 2(8):740-50.