Regular exercise is good for our mental, as well as our physical, health, writes DR GILES WARRINGTON
IT IS now universally accepted that regular exercise has a number of positive outcomes. To date, however, less is known about the effect of physical activity on cognitive function and mental capacity. Cognitive functioning simply relates to all brain-mediated processes and functions which allow an individual to evaluate, manipulate, store and use information from internal and external sources.
Research has shown that people may be able to improve their cognitive function and brain efficiency by making simple lifestyle changes including partaking in regular exercise; performing simple memory exercises such as crosswords and brain training exercises; engaging in healthy eating, in particular consuming a balanced diet high in omega-3 fatty acids, as well as reducing the stress levels in daily living. One study engaging such practices found improvements in brain efficiency after a programme lasting just 14 days.
In one large-scale longitudinal study in Finland, individuals who participated in leisure time physical activity at least twice a week during the mid-life cycle significantly reduced the risk of dementia and Alzheimer's in later life, compared to those who exercised infrequently.
Moreover the results remained significant even when adjustments were made for a range of influencing factors such as age, gender, education, vascular disease, smoking and alcohol consumption levels. With ageing, tissues shrink in critical areas of the brain responsible for mental processing, and these reductions are closely associated with declines in cognitive functioning.
Imaging studies have indicated that there may be anatomical differences in the brains of physically fit, as opposed to less fit, older adults. Specifically, longer duration and suitably intensive exercise has been shown to be most beneficial.
One way exercise may improve cognitive function in the elderly is by increasing their confidence in their own ability, which may result from improved mobility and reduced dependency. Greater self-confidence and independence might be one factor why older adults stay physically, socially and mentally active which have been shown to be key prerequisites of optimal cognitive functioning.
Evidence has suggested that brisk walking has been shown to improve performance in a range of mental tasks for older adults with memory impairment. The precise mechanisms remain unclear, but may in part be related to enhanced blood flow and oxygen transport to the brain during exercise.
More interestingly, aerobic exercise, as well as improving cognitive ability, may be just as effective as medication in treating depression in the middle-aged and elderly. After all, physical activity and physical fitness have long been shown to be positively linked with mental health and wellbeing, and exercise has been associated with a decreased level of mild to moderate depression.
Several studies have shown a positive relationship between academic achievement and both physical activity participation and sports performance. In an attempt to explain this, it has been suggested that increased physical activity during the school day may lead to enhanced arousal and reduced boredom and increased attention span and concentration. Furthermore, increased activity levels may improve self-esteem, resulting in improved class discipline and ultimately academic performance.
It is worth noting, however, that there appears to be an activity threshold necessary to produce these positive effects with vigorous rather than moderate intensity possibly being necessary to achieve the desired outcomes.
Based on these findings, aside from other health benefits associated with sport and exercise, it is ironic that such a low premium is placed on PE provision in the majority of Irish schools. Ireland is languishing at the bottom of the European league tables for classroom time devoted to PE, with many schools not even having a designated specialist PE teacher on their staff.
What is apparent is long-term exercise participation is important for maximising any potential benefits, with acute exercise bouts only having a minimal influence on cognitive function.
While a clear link appears to exist between physical activity and cognitive function and brain health, more research is required before specific recommendations can be made about the types of exercise which should be undertaken, and the dosage in terms of frequency and intensity required to maximise all possible benefits.
• Giles Warrington is a sport and exercise physiologist and lecturer in the School of Health and Human Performance at DCU