'GMA' Workout Wednesday: Celebrity Trainer Harley Pasternak Leads 'Legsanity' Routine

— -- Celebrity trainer Harley Pasternak is bringing his exclusive "Legsanity" workout to a special "GMA" live stream.

"This workout is all about toning, tightening, sculpting an incredible lower body," he told "GMA." "The lower body is the foundation of the whole body. Without strong legs, there is no strong body."

Pasternak, a best-selling author and Fitbit Ambassador, is leading a workout live-streamed on ABCNews.com/live and on the GMA Facebook page today. Fitbit is a sponsor of "Good Morning America."

Watch the video to join the live-stream workout.

Read below for all you need to know about the routine and more tips from Pasternak.

It's important to mix up your routine to see results, Pasternak says.

"Doing the same workout every time can be repetitive -- and boring. It also might cause you to plateau, or worse, cause injury. So try to keep things fresh by mixing cardio with weight training," he told "GMA."

What You Need

'Legsanity' Live Stream Overview

Start with cardio warm up, alternating between these five movements for 1 minute each:

Then, it's onto "Legsanity." Do 1 minute of each move with a 1-minute cardio burst in between.

Pasternak's Tips for the Workout