Physical activity and cognition across the life span

Abstract

Animal studies showed positive impact of physical activity on cognitive abilities. In animal models, exercizing increases the plasticity of the nervous system, enhancing synaptic function, especially for learning. One of the main mechanisms is the increase of attentional capacities enabling faster information processing. Human trials confirmed these results in all ages. Aerobic training of pregnant women has favorable effects on brain development and cognition of their offspring. During the school period children who exercise more vigorously learn better and have better attention. In the adult period physical activity improves cognition and enhances neurogenesis in critical structures such as hippocampus and dorsal striatum. Midlife physical activity prevents cognitive loss in old age. Even if started late in life, aerobic training reduces brain tissue loss and has preventive effects on dementia of all types. There are indications that exercise also exerts influence on the human genome promoting epigenetic modifications. The pivotal factor in aforementioned processes is brain derived neurotrophic factor (BDNF) the molecule that influences energy homeostasis through control of feeding and physical activity. BDNF stimulates glucose transport, mitochondrial biogenesis, increases insulin sensitivity and parasympathetic tone, with positive effects on cognition, emotion, cardiovascular function, and peripheral metabolism. Lack of physical activity impairs BDNF. Exercise upregulates the expression of genes mediating synaptic modulation and signal transduction, increases the volume of gray matter in critical structures of frontal and temporal lobe as shown in neuroimaging studies. Exercise also has the effect of preventing cognitive decline and dementia in old age. Exercise has beneficial effects on cognition in many neuropsychiatric conditions such as stroke, multiple sclerosis, Parkinson’s disease, various dementias, schizophrenia, affective diseases, and also in vascular diseases and diabetes mellitus. Across the lifespan physical activity improves attentional and executive processes, cognitive control, memory and learning, visuospatial abilities, thus improving activities of daily living and quality of life. The recommended types of physical activity are walking, hiking, jogging/running, bicycling, and dance, use of exercise machines, yoga, stretching, tennis, squash and lap-swimming.