A new European study has found that exercise during middle age is linked with better cognition later in life.

The research, carried out by a team from the universities of Helsinki, Jyväskylä and Turku, was a long-term follow-up of 3050 twins from the Finnish Twin Cohort which looked at an association between midlife moderately vigorous physical activity -- described as activity more strenuous than walking -- and cognitive function.

The team of researchers used questionnaires to assess the levels of physical activity, including the volume and intensity of activity, first in 1975 and also in 1981, when mean age of the participants was 45.

Cognition was then assessed between 1999 and 2015 by telephone interviews, when the mean age of participants was 74.2.

The data showed that participation in vigorous physical activity was associated with a lower risk of cognitive impairment later in life when compared to non-participation.

The association was also found even after the researchers had taken into account health factors such as high blood pressure, smoking, obesity, and binge drinking, and social factors such as education level.

However increasing physical activity did not increase memory-protecting benefits, with the team finding that a moderate amount of physical activity was sufficient.

The findings also support earlier studies carried out in animal models, which showed that physical activity could improve synaptic plasticity, which is the ability of synapses to change and strengthen and is thought to contribute to learning and memory.

With rates of dementia on the increase in aging populations globally, and no cure for the condition, the new research also provides more information on dementia prevention and the protective effects of physical exercise, however the team also noted that the amount of exercise needed remains unclear.

The study can be found published online in the Journal of Alzheimer's Disease.