# Exercise as it relates to Disease/Aerobic vs anaerobic exercise for patients suffering from Alzheimer's Disease
## What is Alzheimer's?

Alzheimer's disease (AD) is the most common form of dementia accounting for 50-70% of dementia cases. Over time, this degenerative disease damages the brain caused by oxidation causing beta amyloid plaques. The risk of Alzheimer's disease increases with age and effects mainly those over the age of 60.
Symptoms of AD include:
* Memory loss
* Personality changes (mood swings)
* Cognitive decline
* Inability to cope with everyday activities
* Loss of coordination.

## Prevalence

Alzheimer's currently affects around 34 million individuals over the age of 60 across the world . There are 4.6 million cases of AD diagnosed each year, this figure is expected to triple by 2050.

## Risk Factors

Below is a table of both modifiable and non-modifiable risk factors that can contribute to the onset of Alzheimer's disease.
| Modifiable Risks | Non-Modifiable Risks |
| Being sedentary Cognitive ability Blood Pressure Cholesterol levels Smoking status Diet Drug use | Age Family history Gene type |

## Prevention for Alzheimer's Disease

Diet and physical activity
Participating in regular physical activity as well as managing a healthy diet throughout the mid-life has been shown to decrease some AD risks by up to 60%. Exercise not only decreases the severity of vascular risks of AD, it can also improve cognition, balance, co-ordination and general strength. These benefits can also decrease risk of falls and fractures as well as improve quality of life.

## Benefits of exercise

Aerobic exercise
Aerobic exercise has been shown to be an effective mechanism when it comes to slowing the process of Alzheimer's. Participating in approximately 30 minutes a day of low to moderate intensity exercise has been linked with a increase in cerebral blood flow. This increase in cerebral flow improves brain vascularity and helps maintain neural synapses.
Anaerobic exercise
Short, high intensity bouts of exercise using the anaerobic energy system has not been consistent with the improvements in cerebral blood flow and improvement in cognitive function as has been shown with aerobic exercise. This is because anaerobic exercise does not utilize oxygen as a primary energy source, therefore oxygen does not travel to the brain as efficiently as it would in aerobic exercise. Although anaerobic exercise does not carry the same oxygen delivery capacity as aerobic exercise, it can still be useful to patients suffering from AD. Incorporating skills requiring coordination has also been proven to increase neural synapses and maintain overall brain volume. Engaging in leisurely anaerobic sports like golf and tennis contributes to improved cognition and coordination among AD patients.

## Recommendations

* Those with AD should be encouraged to engage in regular physical activity and follow physical activity guidelines in order to maintain cerebral blood flow as well as maintain coordination, proprioception and reaction time.
* Resistance training should be incorporated into exercise regime for general strength purposes.
* Leisurely activities such as walking, swimming and aerobics have been proven to be effective for those with restricted mobility.

## Further reading

For further information on Alzheimer's disease please refer to the following links
Alzheimer's Australia - http://www.fightdementia.org.au/
Cure Alzheimer's Fund - http://curealz.org/roadmap
Alzheimer’s Australia - www.yourbrainmatters.org.au
Alzheimer’s Association (US) – www.alz.org
National Dementia Helpline - 1800 100 500

## References

* 1 2 3 Katzman, R. (1993). Education and the prevalence of dementia and Alzheimer's disease. Neurology.
* 1 2 3 Radak, Z et al. (2010) Exercise Plays a Preventative Role Against Alzheimer's Disease. Journal of Alzheimer's Disease; 20: 777-783.
* 1 2 Schu, M. C., Sherva, R., Farrer, L. A., & Green, R. C. (2012). The Genetics of Alzheimer’s Disease.
* ↑ Rolland, Y et al. (2008). Physical activity and Alzheimer’s disease: From prevention to therapeutic perspectives. Journal of American Medical Directors Association, 9, 390-405
* 1 2 3 Yu, F., Nelson, N. W., Savik, K., Wyman, J. F., Dysken, M., & Bronas, U. G. (2013). Affecting cognition and quality of life via aerobic exercise in Alzheimer’s disease. Western Journal of Nursing Research, 35(1), 24-38.
* 1 2 Kivipelto, M. and Solomon, A. (2007) Alzheimer's Disease - The Ways of Prevention. The Journal of Nutrition, Health and Aging; 12: 89S-94S.
* 1 2 Intlekofer, K. A., & Cotman, C. W. (2012). Exercise counteracts declining hippocampal function in aging and Alzheimer's disease. Neurobiology of disease.
* 1 2 Young, J., Watt, P., Tabet, N., & Rusted, J. (2013). Are there cognitive benefits from long-term high-intensity exercise in older adults?. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 9(4), P879-P880.
* ↑ Robert S. Wilson, PhD; Carlos F. Mendes de Leon, PhD; Lisa L. Barnes, PhD; Julie A. Schneider, MD; Julia L. Bienias, ScD; Denis A. Evans, MD; David A. Bennett, MD JAMA. 2002;287(6):742-748. doi:10.1001/jama.287.6.742.