A study has offered new evidence of the association between cardiorespiratory fitness and brain health – particularly in the regions of the brain involved with cognitive decline and ageing.

A study from the German Center for Neurodegenerative Diseases (GCND) – published in the Mayo Clinic Proceedings – has shown that cardio exercises has a positive effect on gray matter and total brain volume.

Brain tissue is made up of grey matter, or cell bodies, and filaments, called white matter, that extend from the cells.

The volume of grey matter appears to correlate with various skills and cognitive abilities. The researchers found that increases in peak oxygen uptake (VO2 max) were strongly associated with increased grey matter volume.

The GCND study involved 2,013 adults from two independent cohorts in northeastern Germany.

Participants were examined in phases from 1997 through 2012. Cardiorespiratory fitness was measured using VO2 max and other standards while participants used an exercise bike. MRI brain data also were analysed.

The results suggest cardiorespiratory exercise may contribute to improved brain health and decelerate a decline in grey matter.

According to Ronald Petersen, a Mayo Clinic neurologist, the results are "encouraging, intriguing and contribute to the growing literature relating to exercise and brain health".

"This provides indirect evidence that aerobic exercise can have a positive impact on cognitive function in addition to physical conditioning," Petersen said.

"Another important feature of the study is that these results may apply to older adults, as well. There is good evidence for the value of exercise in midlife, but it is encouraging that there can be positive effects on the brain in later life as well."

The study's finding of higher grey matter volume associated with cardiorespiratory exercise is in brain regions clinically relevant for cognitive changes in ageing, including some involved in Alzheimer's disease.

Petersen called those associations interesting – but cautions against concluding that cardiorespiratory fitness correlations would affect Alzheimer's disease.

• To read the full study, click here for the Mayo Clinic Proceedings – has shown that cardio exercises has a positive effect on gray matter and total brain volume.