Cardiorespiratory exercise - walking briskly, running, biking and just about any other exercise that gets your heart pumping - is good for your body, but can it also slow cognitive changes in your brain?
New evidence of an association between cardiorespiratory fitness and brain health, particularly in gray matter and total brain volume is shown in a study from the German Center for Neurodegenerative Diseases.
Brain tissue is made up of gray matter, or cell bodies, and filaments, called white matter, that extend from the cells. The volume of gray matter appears to correlate with various skills and cognitive abilities.
The researchers found that increases in peak oxygen uptake were strongly associated with increased gray matter volume.
The 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 peak oxygen uptake and other standards while participants used an exercise bike. MRI brain data also were analyzed.
The results suggest cardiorespiratory exercise may contribute to improved brain health and decelerate a decline in gray matter. An editorial by three Mayo Clinic experts that accompanies the Mayo Clinic Proceedings study says the results are encouraging, intriguing and contribute to the growing literature relating to exercise and brain health.
The most striking feature of the study is the measured effect of exercise on brain structures involved in cognition, rather than motor function.
“This provides indirect evidence that aerobic exercise can have a positive impact on cognitive function in addition to physical conditioning. 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,"
says Ronald Petersen, M.D., Ph.D., a Mayo Clinic neurologist and first author of the editorial.
Brain Volume Effects
The study’s finding of higher gray matter volume associated with cardiorespiratory exercise are in brain regions clinically relevant for cognitive changes in aging, including some involved in Alzheimer’s disease. The editorial calls those associations interesting but cautions against concluding that cardiorespiratory fitness correlations would affect Alzheimer’s disease.
“This is another piece of the puzzle showing physical activity and physical fitness is protective against aging-related cognitive decline. There’s already good epidemiological evidence for this, as well as emerging data showing that physical activity and fitness are associated with improved brain blood vessel function. This paper is important because of the volumetric data showing an effect on brain structure,"
says Michael Joyner, M.D., a Mayo Clinic anesthesiologist and physiologist, and editorial co-author. Long-term studies on the relationship between exercise and brain health are needed, which will be costly and logistically challenging to produce.
According to Mayo Clinic experts, moderate and regular exercise - about 150 minutes per week - is recommended. Good cardiorespiratory fitness also involves:
Following healthy eating habits
Losing weight or maintaining a healthy weight level
Managing blood pressure and avoiding hypertension
Controlling cholesterol levels
Reducing blood sugar, which over time can damage your heart and other organs
The study was funded by grants from the German Federal Ministry of Education and Research and supported by the EUJPND Funding for BRIDGET.
 Wittfeld, Katharina et al. Cardiorespiratory Fitness and Gray Matter Volume in the Temporal, Frontal, and Cerebellar Regions in the General Population. Mayo Clinic Proceedings, Volume 95, Issue 1, 44 - 56
 Petersen, Ronald C.Joyner, Michael J.Jack, Clifford R. et al. Cardiorespiratory Fitness and Brain Volumes. Mayo Clinic Proceedings, Volume 95, Issue 1, 6 - 8