It takes a lot of work to maintain six-pack abs and a bangin' booty.

From weight-training to surfing, celebrities have their own fitness regimens to keep them in shape and camera ready. For Blake Lively, she works out with A-list trainer and owner of New York City's Drive 495, Don Saladino. 

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The former Gossip Girl star posted a picture of herself, playfully picking Saladino's nose after an intense work out. "This fit dude @donsaladino NOSE how to kick my butt," jokes Lively. "See what I did there?"

Saladino, who we have dubbed the "Cellulite Doctor," talked to ET about how fit the 28-year-old actress is. "Blake Lively does not have cellulite. I can say that!" he gushes. "Blake loves to train the legs and the abs. She wants strong arms and strong shoulders, so that's something that we incorporate into a full-body workout."

In addition to Lively, Saladino kept it in the family by training her husband, Ryan Reynolds, to get him ripped and toned for his upcoming movie, Deadpool. 

In addition to Lively and Reynolds, Saladino’s past clients have included Liev Schreiber, Scarlett Johansson, and Hugh Jackman.

But when it comes to fitness tips, Saladino has one workout secret that may surprise you: sleep. He told ET, "I had a guy recently add 90 minutes of sleep a night and he lost nine pounds in two weeks."

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Celebrity trainer Jason Walsh of Rise Nation has another workout secret called the Versaclimber that has become the latest fitness craze among his clients. It’s a climbing machine that mimics the movements of scaling a steep mountain. Walsh has trained Hilary Duff, who he has rumored to be dating, as well as husband and wife John Krasinski and Emily Blunt.

"Jason is truly the best trainer," Blunt told ET. "He has trained us both for various action films. He trained me for Edge of Tomorrow and [John] for 13 Hours. You become this kick-ass person you never thought you'd be. It's so cool.”

Walsh has also trained Matt Damon for Elysium, Behind the Candelabra, and the Bourne movies. "Working out with him is hard," admits the 44-year-old actor. "He pushes me as hard as he can go basically."

Saladino and Walsh certainly have great workout secrets and pointers -- and it shows with their body of work. If you need more fitness and dieting tips, watch the video below with celebrity trainer Jillian Michaels.