British Medical Journal (BMJ) research has found that exercise programmes fail to slow brain decline in people living with mild to moderate dementia.
The analysis of NHS exercise programmes found no improvements in the thinking skills or behaviour of more than 300 people over 70 who took part in aerobic and strength exercises over four months, the BBC reported.
On the positive side, the research found the programme did improve the physical fitness of participants.
Prof Martin Rossor, professor of clinical neurology at University College London, said the evidence showed that exercise for people living with well-established dementia may be of limited value.
People in the programme took part in 60-90 minute gym sessions over a four month period.
The sessions included 20 minutes on a fixed cycle and lifting weights while getting out of a chair.
The group was then compared with people living with dementia who received their usual care.
Researchers found that cognitive impairment had declined in both groups, with the exercise group having deteriorated slightly more.
Prof Sallie Lamb, lead study author and professor of rehabilitation at Oxford University, said the results showed people who had been living with dementia with two or three years could take part in simple exercise to improve fitness and muscle strength but the programme had no benefit in terms of cognitive impairment, daily living activities, behaviour or health-related quality of life.