Childhood and adolescence

In childhood and adolescence, being active helps to increase the peak bone mass that is eventually achieved.^15,16 Physical activity is extremely important in maintaining healthy bones.

In childhood and adolescence, exercise contributes to bone modelling (size and shape of bone) and bone mass, and therefore to overall bone strength. In fact, exercise during puberty enhances the natural growth and development of bone during this critical period. Physical activity is extremely important for maintaining healthy bones.

Children should be encouraged to:

• Walk to school or the bus stop (where safe to do so), e.g. walking school bus programs: www.walkingschoolbus.org
• Participate in structured sports (sports involving jumping from different angles, running, skipping and lifting appear to have the greatest impact on bone)
• Play outdoors (where safe to do so)

Sedentary activities such as watching television, playing video games and using computers have increasingly replaced physical activity. Parents and carers can help promote participation by doing physical activities with their children.

Adults

In the adult years physical activity is also beneficial for bone health even though peak bone mass has already been achieved. Exercise results in mechanical signals to the skeleton enabling it to remodel bone in a purposeful manner to achieve maximal strength. Being active is beneficial in a number of other ways: It increases muscle strength^17,18,19  and assists with posture, balance and coordination, which all help to reduce the likelihood of falls²⁰.

Evidence supports the continued benefit of physical activity into old age and extreme old age (80s and 90s) in reducing the risk of falls. Further benefits of being active include improvements in cardiovascular health and self-confidence. All forms of physical activity are beneficial for general health and well-being. However, there are specific types of physical activities that can improve bone health.

Physical activities which are beneficial for bone health

Strength training

These activities are also known as resistance exercises. Strength training use weights of some kind (e.g. machines, dumbbells, ankle or wrist weights) to create resistance, which helps to build muscle mass through loading (force) on the involved limb bones. It also includes activities that use one’s own body weight as the load (e.g. push-ups, where the load is placed through the arms and shoulders).

Load placed on bone leads to increased bone formation at the site where the load is greatest.²¹ The benefit is site specific, so that if (for example) you are using weights on your legs, it only benefits your leg bones.²² Ideally strength-training programs should be performed regularly, 2-3 times per week. Strength training is most beneficial when a small number of repetitions (e.g. 8-12) are used, and the weight is progressively increased. As strength improves, it is best to increase the weight used in the exercise rather than the number of repetitions.

Weight-bearing and high impact activities

Weight bearing activity refers to exercises that are performed in the standing position. This  involves loads (forces) being placed through the feet and transmitted up the leg bones and spine. Examples of weight-bearing exercises include walking, running, tennis and dancing. Studies to evaluate the effects of activities such as walking have not shown as large an improvement in bone mass, except where such activities are performed at high intensity  (e.g. walking at a fast pace, jogging).²³

High impact exercise generally refers to weight bearing exercise that involves more loads being placed through the leg bones and spine, during landing after lifting one’s own body weight off the ground. Examples of this include running, skipping, jumping, high impact aerobics and team sports such as netball.

There is evidence to suggest that high impact loading and resistance type (strength training) activities probably provide the most benefit for improving bone mineral density.^21-27

Types of physical activities with minimal effects on bone health

Types of physical activities with minimal effects on bone health include bike riding and swimming, where there is minimal weight-bearing. However, these types of activities are beneficial in terms of improving cardiovascular health and muscle strength.²⁹

Further resources

Arthritis Victoria has a register of metropolitan and rural strength training programs conducted by health and fitness professionals who have completed professional development courses run by Arthritis Victoria. To locate your nearest class phone (03) 8531 8000 or 1800 011 041

Fact sheets

 Physical Activity 98.89 Kb

Websites

Active Australia

Arthritis Australia

Go For Your Life

National Council on the Ageing accredited strength training programs

Content updated July 27, 2011