A study done at the Montreal Heart Institute in October of 2012 showed that high intensity interval training made overweight and inactive people aged 49 years old healthier and also smarter! Scientists set up a program lasting 4 months where people exercised twice weekly with interval training and twice weekly with resistance training. They measured cognitive function, VO2max, and brain oxygenation and discovered that participatnscognitive functions had greatly improved along with decreased waist circumference, increased insulin sensitivity, and quicker thinking with better recall.
In a second study published in Stroke in October of 2012 people in the 60-80 year old age group who exercised for 30 minutes 3 times a week benefited from a 40% reduction in vascular dementia, and all cause cognitive impairment of 60%. Exercise pays off!