Mighty movement

We tend to think of our skeleton as hard and lifeless. However, just like your skin, the tissue in your bones is constantly being broken down and renewed. 

That’s why it’s important to pay attention to bone health, no matter your age. The bones you build as a teenager can have an impact on the health of your bones in your 60s, 70s and beyond!

In the first few years after menopause, due to declining levels of the hormone oestrogen, most women go through rapid bone loss (where bone tissue breaks down faster than it is replaced). 

This process usually slows, but continues throughout the postmenopausal years, and can commonly lead to the condition known as osteoporosis (fragile bones that are prone to breaking).

But we’re not just at the mercy of our hormones! Building a strong skeleton in your younger years and reducing this bone loss during midlife and beyond, are key.

While swimming and cycling have many benefits for your general health (such as reducing your risk of heart disease), building a stronger skeleton is not one of them. 

In order to build and maintain strong bones, physical activity must be a 'weight-bearing exercise'. That is, exercise that is done on your feet, so you bear your own weight. 

Brisk walking, jogging, dancing, tennis and basketball are all examples of weight-bearing exercises, which all help to stimulate new bone growth and bone renewal.

Bones grow and rebuild themselves more effectively if the weight-bearing exercise involves a certain amount of impact and physical stress. For example, higher-impact activities that encourage higher levels of bone building include netball/basketball, skipping, tennis, boxing, football and dancing. 

Activities with moderate levels of bone building include running/jogging, brisk walking, hill/stair climbing and resistance training. Gentler activities such as leisure walking, lawn bowls and tai chi provide lower levels of bone building. 

Remember, doing some physical activity is better than doing none, so start small and build up gradually.

This amazing fact all comes down to gravity. 

The weaker forces of gravity in space allow the backbones (vertebrae) to stretch out. As a result the spine becomes longer and the body grows taller, usually by about 5cm. Some astronauts have grown over 7cm in height! However, they return to their original height once back on Earth.

To a lesser degree, the same thing happens to us on Earth when we go to sleep each night. As we’re lying down, our spine stretches out and, typically, we wake 1cm taller – but shrink back down during the course of the day. 

This is a bit of trick question! 

Calcium is the crucial nutrient for bone health, giving bones their strength and structure. But without enough vitamin D, your ability to absorb calcium is limited. So, they are equally important.

When we think about the importance of calcium for bones, we need to think about vitamin D too, because their relationship is so intertwined.

Almost 40% of women in Australia may be deficient in vitamin D, and this jumps to 58% during winter and spring.

For most women, the best natural source of vitamin D is the sun.

Your skin produces vitamin D when it is exposed to UV radiation via sunlight, however it’s very important do this safely, so you don’t increase your risk of skin cancer. 

Some of our vitamin D (usually 5-10%) can be obtained through foods such as salmon, tuna, mackerel, cheese and egg yolk, but it is difficult to obtain enough vitamin D from diet alone.

You can find out more about vitamin D in today's article ‘The forgotten nutrient for bone health’.

Women and girls aged 14-18 years need 1300mg of calcium per day for their rapidly growing skeletons.

From 18-50 years, the daily required amount decreases slightly to 1000mg (also applies to pregnant and breastfeeding women).

From 51+ years onwards, it jumps back up to 1300mg/day. This is because with age, our digestive system absorbs less calcium. 

So, what does 1000 or 1300mg of calcium look like? Go to today’s recipe to read more.