A latest study has linked poor fitness during middle age to smaller brains nearly 20 years later. The study findings suggested that health and lifestyle choices can have a huge impact many years later by essentially shrinking the brains of ‘couch potatoes’.

Published online in the journal Neurology, the study included 1,094 participants. The average age of the participants was around 40, and at the start of the study, they were not suffering from heart disease, strokes, or dementia. They weren’t even consuming meds, known as beta blockers for lowering their blood pressure.

The participants took an exercise treadmill test between 1979 and 1983, so that the researchers might judge their estimated fitness level. They exercised with increasing speed and a steeper incline until they got quite exhausted to continue, or in the case of reaching 85% of their estimated maximum heart rate. The researchers measured the test’s effects on the blood pressure of the participants.

Nearly 20 years later, the participants performed a shorter version of the treadmill test alongside brain function testing and an MRI scan for brain volume measurement.

Researcher Nicole Spartano, PhD, from the Boston University School of Medicine said that people with higher heart rates or higher diastolic blood pressure at the time of the treadmill test had tinnier brains later in life.

Besides the link, the researchers discovered that a smaller group of the participants who suffered from heart disease or started consuming beta-blocker meds post the first treadmill test displayed more signs of brain aging later when it was measured.

Spartano said, “Our results suggest that fitness may be especially important for people with pre-hypertension or hypertension [high blood pressure], in order to slow the brain aging process in later life”. She mentioned that further research is required to know whether exercise makes a difference or not.