Sorry, Netflix fans. All that binge-watching, it turns out, makes your brain grow old before its time. Researchers at the Northern California Institute for Research and Education in San Francisco looked at the television-viewing habits of more than 3,000 participants over a quarter-century — and the results don’t look good for folks who spend long hours in front of the screen.

People who spent three hours a day watching TV and did little exercise experienced worse midlife executive function. That means their mental skills — like managing time, paying attention and remembering details — were worse than their more active peers.

The study authors point out that it’s not the TV shows that are zapping your brain powers — it's the fact that you are feet-up on the couch while watching that really matters. Cardiovascular exercise, after all, has many well-documented brain (and overall) health benefits.

You’re also not putting your brain through its paces when you’re mindlessly following your favorite characters for hours at a time.

Your next move? Hit the power button on the remote control, and get off the couch. This study shows that cutting back on your TV time may help prevent cognitive aging before middle age.