Written & Medically reviewed by
Dr.Sanjana.V.B. Bhms. Dbrm.Cdn

Physical activity to prevent osteoporosis & bone fracture

    Bone health deteriorates with ageing under the influence of various factors such as declining hormones, low vitamin D formation, calcium depletion etc. Osteoporotic fractures are common particularly in post-menopausal women.

   Bone mineral density decreases in old population. Diet has crucial role in maintaining vitamin D ,calcium, magnesium and phosphorus levels in the body protecting the bones against fractures from low bone mass. In addition to diet, physical activity also has vital role in improving bone health.

    Bone health is intricately connected to physical activity and exercise. Weight-bearing or strength training exercises have important role in maintaining bone strength and preventing osteoporosis particularly in old people.

 Maintaining muscle mass also preserves and strengthens surrounding bone and helps prevent falls.  Brisk walking, dancing, climbing stairs, jogging etc. can stimulate your body's bone-forming cells and helps bones become stronger.

    Bone health is depended on various other factors such as age, smoking, a history of falls, diabetes, inflammatory and autoimmune diseases, certain medications that cause bone loss, and reduction in bone mineral density [ BMD]

.A bone mineral density (BMD) test is the way to measure your bone health. It compares your bone density, or mass, to that of a healthy person who is the same age and sex as you are. It can determine if you have osteoporosis or  your osteoporosis treatment is working in the right direction.

   Genetic factors or your hereditary predisposition also plays a key role in bone health. A few women have genetically determined increased bone turnover after menopause or with aging. That means some women in post-menopausal age group have inherited risk of bone fractures. Bone mineral density can be tested in risk groups in order to avoid fracture. 

    According to NIH[ National institute of health, U.S.A] , more than 75 million people in the United States, Europe, and Japan are diagnosed with osteoporosis, and over 4.5 million fractures occur annually in the United States and Europe.

   Physical activity is a viable strategy for the prevention and treatment of low bone mass. Low bone mass may increase bone fragility and thus enhanced risk for osteoporotic fracture.

Hip fracture is the most common fracture associated with osteoporosis, and it is the leading cause of disability in the elderly.

How does physical activity &exercise help bone strength?

  Physical activity allows for targeted strengthening of the hip and spine, as sufficient skeletal loading associated with physical activity stimulates net bone formation at the stressed skeletal sites.

 Mechanical loading is an effective way to increase bone mass, decrease bone loss, and improve bone strength. Mechanical loading is a potent stimulus for bone cells, which improves bone strength and inhibits bone loss with age. Bones may accumulate damage from loading, but it is capable of self-repair also.

The replacement of old bone tissue by new bone tissue is called  bone remodeling. Bone formation, repair and remodeling is controlled and produced by four types of cell, namely osteoblasts, osteoclasts, osteocytes and bone lining cells. Bone remodeling is regulated by signals to these cells generated by mechanical loading.

 Simply standing upright, resisting the force of gravity puts a load on bone, however human body is well adapted to this load on bones. In order to build stronger bones by remodeling process a much higher load is required. The load put on bone can be measured in terms of multiples of body weight. Higher loads can stimulate better bone growth and build up strength. For strong stimulation, the load needs to reach around 4 times body weight.

Effective bone strength building physical activities in the order of their potential to stimulate include:

Brisk walking : 1–2

Running/jogging:  3–4

Power jumping: 4+

Resistance, strength training:  4 to 10

Facts to know about building bone strength

  Studies have shown that the benefits of physical activity on bones achieved during adolescence persist into young adulthood, while activity-associated bone loading during young adulthood increases BMD in middle-age and older adulthood. Therefore it is advisable to promote physical activity right from childhood. It should be continued in all age groups, including old people.

In addition to increasing BMD,  mechanical loading during adulthood increases bone size, its cortical area and strength. It may reduce hip fracture risk later in life.

Resistance training is recommended by the National Strength and Conditioning Association to increase BMD or to prevent age-associated reductions in BMD.

Preventive formula against bone loss, osteoporosis &falls

 Bone health demands practice of certain habits and avoidance of some risk factors. They include:

 Remain physically active every day as it can boost bone health. 

·       Strength-building and weight-bearing activities help build strong bones and muscles.

·       Old people are advised to do only moderate activities in order to avoid age related fractures.

·       Children should exercise at least one hour each day and adults should get 30 minutes of daily activity.

·       Maintain a healthy weight. Elderly who are overweight have a higher risk for falling as well as chances of developing arthritic changes on weight bearing joints. While, underweight also raises some health risks such as bone loss and fractures.

·       Ensure adequate intake of calcium and Vitamin D.  The health of our bones depend on constant supply of nutrients in the recommended allowances, most importantly calcium and Vitamin D. Sun exposure or vitamin D supplements are very essential for health of bones.

·       Avoid smoking.  Smoking can reduce bone mass and increase your risk for a broken bone. Nicotine inhibits bone-forming cells.

·       Restrict alcohol use.  Heavy alcohol consumption may reduce bone mass, weakens bones and increases your risk for falls and broken bones.

·       Reduce the risk of falling particularly in old age.  Exercise can help reduce your risk of falling by strengthening bones and muscles.

References

1.    1. DHHS, U. Bone Health and Osteoporosis: A Report of the Surgeon General. Rockville, MD: 2004. [Google Scholar] [Ref list]

2.    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6179512/

3.    https://pubmed.ncbi.nlm.nih.gov/16834564/

4.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743123/#:~:text=Mechanical%20loading%20stimulates%20bone%20formation,engineers%20to%20achieve%20optimum%20structure.

5.https://www.physio-pedia.com/Mechanical_Loading_of_Bone