A study of healthy, older adults has shown that even a single session of exercise can increase activity in the brain circuits associated with memory.

Research by the University of Maryland – published in the Journal of the International Neuropsychological Society showed that exercise increased activation in the hippocampus, which shrinks with age and is the brain region attacked first in Alzheimer's disease.

"While it has been shown that regular exercise can increase the volume of the hippocampus, our study provides new information that acute exercise has the ability to impact this important brain region," said Dr. J. Carson Smith, the study's lead author and associate professor of kinesiology at the University of Maryland School of Public Health.

The research team measured brain activity using fMRI of people aged between 55 and 85 years.

Participants were asked to perform memory tasks which activated a neural network related to semantic memory – which is known to deteriorate over time with memory loss.

The test was conducted 30 minutes after a session of moderate exercise (70 per cent of max effort) on an exercise bike – and on a separate day after a period of rest.

Participants' brain activation was significantly greater after exercise compared to after rest. The increased activation of the hippocampus was also seen on both sides of the brain.

"Just like a muscle adapts to repeated use, single sessions of exercise may flex cognitive neural networks in ways that promote adaptations over time and lend to increased network integrity and function and allow more efficient access to memories," Dr. Smith added.

To read the full studyin the Journal of the International Neuropsychological Society, click here.