Exercising prevents the brain from shrinking according to researchers at the Boston University School of Medicine. The researchers note that the brain shrinkage is small but enough to increase the risk of memory loss and dementia.

Senior author Sudha Seshadri explains that shrinkage correlates with fewer brain cells and synaptic connections. The study, published in the journal Neurology on Feb. 10, involved recruiting 1,583 middle-aged participants, on the average of 40 years, who did not have dementia or heart disease. The researchers performed a treadmill test and MRI scan on them.

The participants were reassessed 20 years later through the same process. On the average, the participants have an exercise capacity of 39 mL/kg/min (millilitres of oxygen per kilogram body weight per minute). This is also known as peak VO2, the highest amount of oxygen the body can use in a minute.



The team found out that those who performed poorly as 40-year-olds were more likely to experience brain shrinkage 20 years later. For each 8 mL/kg/min lower estimated VO2 max, 17 beats per minute higher heart rate or 14 mm Hg higher diastolic blood pressure during exercise, the participants’ brains aged one year. According to study author Nicole Spartano, from the Boston University School of Medicine, the effect was not big but was still observed even after other factors, including high blood pressure, smoking and diabetes, have been adjusted.

The researcher says that the study is observational and this only shows the link, not the proof that poor physical fitness will automatically cause brain shrinkage. Nevertheless, this highlights the importance of exercising in midlife to help against age-related diseases as well as brain atrophy.

Another study, conducted by researchers in Suomen Akatemia in Finland, has shown the benefits of aerobic exercise on brain structure and function. The study, published online in the Journal of Physiology on Feb. 4, states that sustained aerobic exercise such as running can encourage neuron growth, also known as neurogenesis.