Regular cardiovascular activity may help improve memory and thinking skills in middle age, a new study suggests. A total of 2,747 healthy young adults completed treadmill tests at the beginning of the study and did so again after 20 years. Participants completed cognitive tests 25 years after the study began to measure higher thinking, verbal memory and psychomotor speed. Results revealed a link between the length of time participants could run and performance on the psychomotor speed and memory tests. Details of the study appear in the journal Neurology.