I am sure many of you know the feeling of pressure when thinking about all the money you pay for the gym that you last visited over one month ago. Why didn’t you go there yesterday or the day before or the day before that? In this article, I will give you sufficient reasons from a neuroscientific perspective for why you should exercise regularly!
Why is physical exercise important?
I do not need to tell you about the obvious reasons like physical shape, strength, flexibility, and exercise induced endorphins that you gain when you are physically active. However, exercise also appears to have enormous upsides for our brains, meaning physical activity is good for your cognitive health. Recent studies hint at an improvement of cognition as well as a reduction of the risk of cognitive decline at an advanced age.
Due to the plasticity of the brain, physical activity evokes structural as well as functional changes in the brain. This affects among other things, grey and white matter volume, blood vessel number as well as neurogenesis in the hippocampus. Furthermore, communication between brain regions is altered such that network connections are deepened when exercising regularly. These changes lead to substantial benefits for the brain that can be measured with the help of neuroimaging techniques and behaviourally in participants’ cognitive performance.
Effects on the brain – structural and functional changes
Due to physical exercise, changes in blood flow and vascularization take place. This has the positive effect of an overall better oxygen and nutrition supply in the brain which shows itself by a higher number of small cerebral blood vessels in physical active people.
Structural changes measured by neuroimaging techniques after physical exercise show an increase in grey matter volume in frontal brain regions and an increase of hippocampus volume. Greater task-related activity in prefrontal and parietal areas was found in an aerobic training group compared to a control group. Those changes in brain structure in combination with better behavioural performance can be taken as correlational evidence for an increased neuronal efficiency during task execution.
Changes in the brain are not restricted to certain regions and their structure, but are also visible through stronger connectivity between brain areas. Especially within the default mode network and the frontal executive network, physical exercise facilitates stronger connectivity. Presumably, experience-related structural changes have a direct effect on the functional magnetic resonance imaging signal. However, the relation between structural and functional changes is still not fully understood.
The above mentioned changes in the brain are often directly linked to cognitive functions. That is, behavioural performance of physically active and non-active people differs in cognitive tasks.
Effects on cognition
There are several intervention studies that investigated the relation between physical exercise and cognitive functioning. In general, performance in cognitive tasks increases after a training phase accompanied by larger increases in executive functions, memory, attention, and speed of processing. In children, aerobic fitness was indicative of recognition memory performance. Likewise in younger adults a significant increase in visuo-spatial short-term memory was observed after 6 weeks of aerobic exercise training compared to a waiting group. In middle-aged adults significant improvements in memory were found after a cycling training compared to a sedentary control group.
However, the question about a general transfer effect on cognition versus specific performance increase restricted to a subset of cognitive tasks is not completely resolved yet. Another question is if long-term effects of physical training can be observed or if performance declines after the physical training is abandoned. Moreover, it seems that certain subgroups of the population are better suited for gaining positive cognitive effects from physical exercise than others. Particularly in later life, exercising can have many of benefits for overall health and cognitive function of elderly adults.
Physical exercise has a protective effect against cognitive decline in ageing. The effect is twofold; midlife physical exercise affects brain health in later life. Additionally, exercising in later age also slows the trajectory of normal ageing.
When physically exercising at the age of 36, a slower rate of memory decline between the age of 43 and 53 was observed. Furthermore, stopping exercise after the age of 36 resulted in a lower protection of memory functions compared to adults who started exercising after 36 years of age. The lowest decay in memory at the age of 53 years was observed in adults who exercised at the age of 36 as well as at the age of 43 years. These results suggest that continuous exercising helps maintaining cognitive capacities across the lifespan.
Becoming physically active even at a later age can also help to protect cognitive functioning. A 6-month training intervention with sedentary adults aged 64 to 78 found that aerobic exercisers compared to controls show better performance of episodic memory, processing speed, updating, and executive function tasks. These results lead to the assumption that exercise has a broad influence on cognitive functioning rather than specific improvements in cognition.
This influence on cognitive functioning is not restricted only to the physically active person. Improved health of body and brain can also affect other people, especially the coming generation.
Epigenetics – prosperity of your offspring
Physically exercising not only has a positive effect on your own overall health of body and brain, but the impact of exercising can be seen as an environmental influence that can be saved in the genome via epigenetic mechanisms. One of the multiple mechanisms epigenetics relies on is chromatin modification. This means that changes in gene expression are made through the modification of chromatin. However, these changes do not alter the DNA sequence itself.
Through physical exercise gene regulatory mechanisms can be influenced. Physical activity is able to affect transcription of genes that are necessary for maintenance of cognitive function. The results suggest that physical exercise triggers epigenetic mechanisms that affect future generations. Thus, the beneficial effects of exercise can be epigenetically inherited. For example, exercise can elicit epigenetic modifications that increase resistance to diseases, and these modifications can be transferred to the progeny.
Just do it! I hope you are motivated to train your body and brain right now. Just do it!