Dementia is an acquired progressive impairment of intellectual function and cognitive skills with associated changes in behaviour, costing the UK economy £23 billion each year.1 In the Western world around 60% of cases are due to Alzheimer’s disease, with vascular or multi-infarct dementia accounting for 15–20% of cases. Patients with dementia experience problems with mobility, activities of daily living (ADLs), depression and insomnia. 

The benefits of exercise in the prevention and treatment of many diseases is well known. Animal studies have found that exercised mice, rats and monkeys have significantly better memory and object recognition scores than immobilised animals and decreased anxiety and startle response.3,4 There is evidence that more active individuals, especially those who undertake exercise at least three times a week, are at a significantly lower risk of dementia.5

  Treatment of dementia involves offering support to the patient and family and the prescription of medications for some patients. Current NICE guidelines recommend the use of acetylcholinesterase inhibitors for those with moderate severity Alzheimer’s dementia.6 There is increasing evidence that patients with mild to moderate dementia can experience multiple benefits from an exercise programme; including improved strength, cognition, physical fitness, behaviour and a slower rate of functional decline.7,8 However those with cognitive impairment are often seen as too frail or cognitively impaired to benefit from exercise programmes and are often excluded.9

A meta-analysis published in 20089 compared the effects of exercise rehabilitation programmes on cognitively impaired (mild-moderate impairment) and cognitively intact older patients. Overall a positive effect was reported for both groups. “No statistically significant difference in effect sizes were found between the cognitively impaired and cognitively intact studies on strength, endurance and combined strength and endurance effects.”9 Findings suggest that cognitively impaired individuals should not be excluded from exercise programmes and can gain as much as cognitively intact individuals.

The best evidence supports aerobic exercise, with limited evidence for the benefits of resistance exercise. Studies have found that exercise programmes can be successfully initiated for both home and care home or hospital-based patients with dementia.10

Home/out-patient based dementia care
Looking after a patient with dementia can be a burden to family, carers and society. Due to weakness and deterioration in function, cognition and behaviour patients are at increased risk of falls and fractures. Eventually functional decline leads to institutionalisation of around three-quarters of patients with dementia.11 Exercise can be an effective intervention to delay or prevent this.

Studies have assessed the impact of home-based exercise on those with dementia with regards to: function, strength, walking speed, depression/mood, quality of life (QOL), mortality and Mini-Mental State Examination (MMSE) score.

Studies have shown that community-based exercise is feasible for patients with dementia.10,12 Carers can be taught how to supervise a home-based programme. In one study carers were trained in behavioural management and the delivery and supervision of an exercise programme. One hundred and fifty three home-based patients with dementia found that a three-month carer-delivered intervention including aerobic, strength, balance and flexibility activities resulted in significantly improved physical function and mood state with less restricted activity days reported in the intervention group.12 Improvements in physical function remained at a 24-months
follow-up.12 

A review in 2011 reported that physically active patients with Alzheimer’s dementia had a significantly reduced mortality and women with dementia undertaking a one year regular exercise programme were found to have significantly improved MMSE scores compared with sedentary controls.In a study involving 27 home-based patients with a diagnosis of likely Alzheimer’s dementia, significant improvements were found in hand function, with a trend towards improvements in lower extremity strength.10 Patients undertook a 12-week daily exercise programme involving a brisk walk, strength, balance and flexibility training.10 There was no difference in the eight foot timed walk speed and a slight worsening of depression and QOL scores.10

Most studies only include patients with mild-moderate cognitive impairment and do not note an association between MMSE score and outcome. A double blind randomised trial in an out-patient setting using a strength and endurance exercise intervention in patients with an MMSE 17–26 found significant improvements in strength and functional performance.13
Improvements were not related to MMSE score but those with the worst motor performance prior to the programme were found to gain the most.13 One study, with 29 subjects, included 11 with severe dementia (MMSE less than or equal to 12).14 More than 50% of participants completed the majority of the movements in the sessions.14 A low level of activity was not associated with any improvements but a higher rate was associated with improvements in the timed get up and go test.14 Low MMSE was associated with low performance.14 

Care home based dementia care
It is thought that up to half of care home residents may suffer some degree of cognitive impairment.9 This population could be an ideal group of patients in whom to initiate an exercise intervention. Not only can patients benefit from exercise but also from the interaction and feeling of community that can be created with group sessions.

One hundred and thirty four patients with mild to severe Alzheimer’s dementia took part in a bi-weekly group exercise programme that included aerobic exercise, strength, balance and flexibility training; this was compared with routine care.15 Patients were randomised into groups. After 12 months a slower rate of decline in ADLs was noted in the intervention group.15 A potential difficulty in patients with dementia, especially those with more severe cognitive decline, is increased frailty and comorbidities, which can result in poor compliance to an intervention. In this study the overall compliance to the programme was relatively low at 33.2% but those who attended more sessions showed a significantly slower decline in mean ADLs. This could be because those with a slower rate of decline were more able to participate in the exercise.15 There was no difference in depressive symptoms or behavioural disturbance.15

Additional benefits have been noted where exercise is combined with cognitive activity. Sixty-five nursing home residents with Alzheimer’s dementia were randomised to receive 30 minutes assisted walking, 30 minutes conversation or both interventions simultaneously, three times a week, for 16 weeks.11 Patients’ functional mobility deteriorated significantly less in the combined intervention group than in the assisted-walking or conversation groups.11 The degree of deterioration in functional mobility was related to compliance with the intervention; patients in the combined group received 75% of planned interventions while those in the assisted walking group received just 57%.11 Combining conversation with assisted walking resulted in greater compliance and improved outcomes.11

Multi-sensory exercise
Multi-sensory exercise, which includes exercise with imagery, cognitive activities and music, has been found to be an effective way of improving cognition and mood
in dementia. One study compared a music-based dance programme, focusing on improving strength, flexibility and balance, for 30 minutes per day for three months. The control group received a 30 minute daily conversation intervention.16 All were inpatients diagnosed with dementia (MMSE score < 24).16 After three months there was a significant improvement in MMSE scores of the exercise group but no significant effects on behaviour were reported.16 

A further study17 involving 13 nursing home residents found an improvement in overall mood in eight residents and a significant improvement in resting heart rate but no improvements in blood pressure or weight following a multi-sensory exercise programme undertaken three times a week for eight weeks. The exercise programme was designed to ensure participants remained stimulated and engaged throughout and included music, storytelling
and imagery.17

Other considerations
In addition to the effects of exercise on physical function, cognition and mood, exercise has the potential to positively impact other aspects of dementia care. Insomnia and depression are common, “insomnia affects up to 35% of community-dwelling adults with dementia.”18 30-minutes of daily walking outside has been shown to be effective in the management of insomnia in patients with Alzheimer’s dementia.19

Exercise has been shown to reduce depression and depressive symptoms in those with dementia.12,19 However, some authors found no effect or a worsening of
depression scores.10,15

Conclusion
Exercise can be an effective intervention in the management of dementia. Studies have shown wide-ranging benefits from a variety of exercise interventions; including aerobic exercise, strength, balance and flexibility training. Positive effects have been noted on mortality, physical function, strength, MMSE scores, mood state and resting heart rate. Following an exercise intervention adults with dementia have been found to have less restricted activity days and a slower rate of decline in ADLs. Moreover interventions have been found to be enjoyable and feasible in those with a wide range of cognitive impairment. 

No improvements have been noted in blood pressure, weight or behavioural disturbance and there are conflicting results on outcomes such as depression, walking speed and QOL.
While more research is needed, particularly in regards to exercise interventions in those with more severe dementia/cognitive decline, benefits have been shown and no negative outcomes have been reported. One study15 found no significant difference in falls or fractures between the intervention and control group and another20 reported that patients found the intervention enjoyable. Given these findings; exercise as a therapy for dementia requires more research but should be encouraged in those who are able. Many studies reported good to excellent compliance10,12,19 with a few noting poor compliance. In particular poor compliance has been reported in those with greater cognitive decline. None of the studies reviewed looked at a cost analysis and whether the intervention was cost effective. This is of importance if exercise interventions are to be recommended for elderly patients with dementia, especially with varying compliance.

Studies into exercise in patients with dementia can be difficult to carry out and interpret. The majority have small sample sizes and short follow-up, usually less than one year. Due to the progressive nature of the disease it can be difficult to determine the true effect of an intervention and the amount of decline that may have been prevented. In addition, studies use different levels of MMSE for mild, moderate and severe dementia/cognitive decline, making it difficult to generalise results. However it should be noted that, except in those with an MMSE of 12 or less, improvements were noted.

In summary exercise for those with dementia is feasible and good compliance can be achieved. With an ageing population further research is required to determine the cost-effectiveness of exercise programmes and to identify those who are most likely to benefit.


Conflict of interest: none declared.


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