# Exercise as it relates to Disease/Exercise and preventing osteoporosis
## Osteoporosis

Osteoporosis is a disease of the bone which predominantly affects the aged population, more often females become osteoporotic than males during their lifetime. Osteoporosis comes about through the gradual deterioration of Bone Mineral Density (BMD), thus meaning that the bone structure becomes far weaker, even brittle to a certain extent and is therefore a lot more susceptible to fractures and breaks

#### Prevalence

Osteoporosis is the most common bone disease as an estimated 200 million people worldwide are dealing with some severity of osteoporosis. The main reason osteoporosis is more common in women than men is due to women going through menopause which results in their oestrogen levels dropping significantly. As oestrogen levels drop the breakdown of bone becomes far greater due to the increased activity of osteoclasts which are enzymes that breakdown bone tissue this greatly lowers their BMD

#### Why It's An Issue

Due to the majority of people suffering from osteoporosis being of an older age mobility and everyday living can become a very large issue. The quality of living being effected from osteoporosis can have a large impact on everyday activities such as; grocery shopping, house cleaning and some forms of exercise dependent on the severity of their osteoporosis.

## Causes of Osteoporosis

There are a lot of things that can effect the development of osteoporosis which include:
* Deterioration of bone tissue
* Decreased bone mineral density
* Loss of collagen fibres
* Decreased hormone levels (oestrogen, testosterone)
* Minimal or No exercise
* Low calcium intake and poor diet
* Large amounts of sedentary behaviour
Some factors that effect the chances of being diagnosed with osteoporosis can be preventable while others can't be changed as shown in the table below:
| Preventable Factors | Non-Preventable Factors |
| Smoking | Gender |
| Amount of Exercise | Age |
| Low calcium intake | Genetics |
| Sedentary behaviour | Menopause |
| Peak bone density | Previous fractures |

## Exercise Prevention

With the main problem of osteoporosis being the loss of bone mineral density and bone structure, the idea behind exercise prevention is to maintain or even increase that BMD thus decreasing the chance of falls, fractures or breaks and the onset of osteoporosis Exercise prevention can start as early as childhood because it is very important to have a high peak bone density or bone mass before it starts to deteriorate with age. Peak bone mass occurs around 25–30 years of age, the higher someones peak means they have more bone mass to lose before it becomes a serious issue thus decreasing the risk of osteoporosis What studies show is that exercise type is very important, resistance training and weight-bearing or high impact exercise including; weightlifting, running and jumping exercises has a far greater effect on increasing and maintaining BMD while non-weight-bearing exercise such as swimming has little to no effect and at best will only help maintain BMD levels

## Exercise Recommendations

Each type of exercise requires different time and frequency to have an effect in preventing the onset of osteoporosis and some is more effective than others This is shown in the table below:
| Exercise type | Time (min) | Frequency | Effectiveness |
| Weight-bearing (high impact) | 30-50 | 3–5 days/wk | Very effective |
| Weight-bearing (low impact) | 30-45 | 3–5 days/wk | Effective |
| Resistance Training | 30-50 | 3–5 days/wk | Very effective |
| Non-weight-bearing | 45-60 | 3–5 days/wk | Not very effective |
As shown above some exercise types are more effective at increasing BMD than others. The exercise types that are recommended for developing bone strength and preventing osteoporosis are high impact weight bearing exercises or resistance training exercise. To get the best results it must be regular exercise upwards of 3 times a week and preferably of a minimum of 30 minutes per session. Although if the person was of an older age they may be unable to perform these high-impact exercises so they would be recommended to do low-impact weight bearing or low loads with resistance training, they may even do water based weight-bearing exercises if they are of a very elderly age because they may be at risk of a fall or injury with out of water exercise

## Further reading

* Osteoporosis Australia and International Osteoporosis Federation Exercise Recommendations
* Medical Journal of Australia

## References

* 1 2 3 Pei-Yang, L. et al. (2011) 'Aerobic Exercise and Whole-Body Vibration in Offsetting Bone Loss in Older Adults'. Journal of Aging Research. Vol. 2011, Article ID 379674, pp 1-9
* 1 2 3 R.C. Offer (2001) 'Osteoporosis and menopause: Taking charge of bone health'. BCMJ, Vol. 43, No. 8, October 2001, page(s) 458-462
* ↑ Jean-Yves Reginster, (2005) 'Osteoporosis: A still increasing prevalence'. World Health Organization Collaborating Center for Public Health Aspects of Rheumatic Diseases, University of Liège, Liège, Belgium.
* 1 2 KaiMingChan, (2003) 'Exercise interventions: defusing the world’s osteoporosis time bomb'. Bulletin of the World Health Organization.
* ↑ Martin Nilsson, (2012) 'Increased physical Activity is Associated With Enhanced Development of Peak Bone Mass in Men: A Five-year Longitudinal study'. Journal of Bone and Mineral Research 2012 May; 27(5): 1206–1214.
* ↑ , J A Todd, R J Robinson (2003) 'Osteoporosis and exercise'. Postgraduate Medical Journal 2003;79:320-323
* ↑ , Peter R Ebeling (2011) 'Building healthy bones throughout life: an evidence-informed strategy to prevent osteoporosis in Australia'. Medical Journal of Australia 20 October 2011
* ↑ , Ed McNeely (2010) 'Training to Improve Bone Density in Adults: A Review and Recommendations'. United states sports academy, the sports journal 2010