Tim Bach
Like most Australians over the age of 70, my GP referred me for a bone scan as a routine check on my bone health. I was surprised to learn that I had low bone density (osteopenia) despite what I consider to be my relatively healthy, active lifestyle.
As we age, preserving bone strength becomes a crucial part of healthy ageing. A decline in bone mineral density leads to conditions such as osteopenia and osteoporosis, increasing the risk of fractures. While much of the research has focused on post-menopausal women, the problem also affects older men.
According to the Australian Institute of Health and Welfare, about 853,600 Australians were living with osteoporosis or osteopenia in 2022, roughly 3.4 per cent of the population. The prevalence rises sharply with age: among those aged 75 and over, about 17 per cent are affected.
Bones are living tissues that are constantly remodelled according to the forces (stresses) placed on it. Old bone is resorbed by specialised cells called osteoclasts and new bone is built by bone-forming cells called osteoblasts that deposit calcium and phosphate into the bone matrix. When mechanical load is applied through weight bearing, impact, or muscle contraction, the stresses cause microscopic compression or stretch of the bone proportional to the stress. These small length changes are the signal for more bone deposition. Where there is little load, bone formation slows and resorption by osteoclasts dominates.
In Australia, Medicare covers a bone density test for everyone aged 70 and over, or younger people with risk factors such as prior fractures, low body weight, or long-term steroid use.
Calcium and vitamin D play key roles in maintaining healthy bones. The recommended daily intake of calcium for adults is about 1,000 milligrams, higher for post-menopausal women and men over 70. Vitamin D helps the body absorb calcium from food. Without enough vitamin D, even a calcium-rich diet cannot effectively support bone formation. Vitamin D is produced in the skin with sun exposure but can also be obtained from food sources such as dairy products, fortified plant milks, leafy greens and fish with edible bones. If sun exposure is limited or vitamin D deficiency is indicated in a blood test, supplements may be appropriate, but this should be discussed with a doctor.
Adequate calcium and vitamin D are necessary for bone building, but without physical stress the process is less effective. The most efficient way to maintain bone strength is to combine mechanical loading with good nutrition.
Exercise is the most effective lifestyle strategy for maintaining bone density. Weight-bearing activities such as brisk walking, running, stair climbing and dancing stimulate the skeleton to maintain its strength. Resistance training, using weights, bands, or body weight, strengthens muscles and places mechanical stress on bones, which in turn stimulates bone formation.
In my own case my favourite sport was, and still is, swimming. But swimming is a body-weight-supported exercise and does not stress bones as much as land-based activities. Perhaps my lifelong passion for swimming has contributed to my low bone density and swimming is certainly not the solution. Swimming will maintain and improve my cardiovascular health but it will not improve my bone health. I need to do resistance training and incorporate more walking, running and dancing!
Many empirical studies have shown that programs combining resistance and impact exercises improve bone density in older adults. People with low bone density or osteoporosis should undertake supervised exercise programs combining impact, resistance, and balance training to strengthen bones and reduce falls.
For most older adults, three or more sessions per week of bone-loading activity are recommended. This should include brisk or uphill walking, light jogging, or stair climbing. A program of resistance exercises for major muscle groups at home or in a gym should be done two or three times per week. Activities should be progressive and challenging but always safe. Those diagnosed with osteoporosis should consult a physiotherapist or exercise physiologist for an individually tailored program. People with heart conditions, arthritis, or other chronic diseases should check with their doctor before starting new exercise routines.
Anyone who receives a bone density scan showing osteopenia or osteoporosis should discuss the results with their GP. Low bone density may have many causes, including hormone changes, medications, nutritional deficiencies, or underlying disease. A GP can interpret the scan, assess fracture and falls risk, and recommend lifestyle changes, medications, or referrals to specialists. Early assessment and management can prevent fractures and preserve independence.
To maintain bone health, older adults should eat a balanced diet rich in calcium, ensure adequate vitamin D through safe sun exposure or supplements if required, and keep active with both weight-bearing and resistance exercises. Avoid smoking and excessive alcohol, which both accelerate bone loss. Maintaining a healthy body weight also supports bone strength, as being underweight increases the risk of bone loss. Some medications, such as long-term corticosteroids, can weaken bones, so it is important to review prescriptions with a GP.
Several authoritative websites provide reliable guidance on bone health and exercise. Healthy Bones Australia offers practical information on exercise programs and dietary advice. Better Health Channel (Victoria) provides information about prevention, bone density testing, and treatment options. HealthDirect Australia also offers plain-language guidance about bone scans and fracture risk.
The team at Springs Medical, Daylesford, is well placed to advise on bone health. After my diagnosis of osteopenia, my GP referred me to one of the Springs exercise physiologists who developed a tailored gym program to address my specific needs. Two years on, a follow-up scan has indicated significant improvements in my bone density and motivated me to continue the gym program as part of my weekly physical activities.
Tim Bach is a retired Associate Professor with an academic background in Biomechanics, Exercise Physiology and Rehabilitation. He is also the Editor of The Wombat Post.
