The one thing celeb trainer Harley Pasternak tells all of his famous clients to do for best results

Staying in shape can definitely be an investment. But before you dip into to your vacation fund to join a luxe gym, you may want to listen to this free advice from fitness trainer Harley Pasternak, who’s worked with Mandy Moore, Miley Cyrus, and Maria Menounos (just to name a few of his famous clients).

“Walk. I tell my clients you’re wasting your time and my time coming to work out if you’re sedentary the rest of the time,” Pasternak said at a recent Reebok Speed TR launch event in New York City. “We’re the most sedentary civilization in the history of humanity. As a result, we’re more unhealthy than we’ve ever been. It’s primarily tied to a lack of movement. And as we become more technologically savvy with every innovation, we move less and less,” he says.

“We’re the most sedentary civilization in the history of humanity.”—Harley Pasternak

So, how much do you really need to walk each day? “Twelve thousand steps is the minimum for the average person, if you want to be in good shape and 14,000 if you want to get ripped,” Pasternak advises. (Twelve thousand steps is the equivalent of about 5.6 miles and 14,000 steps clocks in around 6.6 miles, FYI.)

If you’re feeling inspired to get out and move more, maybe pick up a fitness tracker or download an app to help you stay accountable. And, now that you’ve saved some cash, a super-comfy pair of new sneakers will be extra-motivational, right?

This celeb trainer’s surprising take on the ketogenic diet is a must-read. And see how this one’s helping Hollywood A-listers get in the best shape of their lives.