How do Blake Lively and Ryan Reynolds enjoy the holiday season while maintaining their healthy habits? Now that's a secret we're more than happy to tell. 

When it comes to his clients, the beloved couple's longtime trainer Don Saladino is all about establishing a sustainable and enjoyable wellness routine. And clearly, he's very good at what he does as the fitness expert has helped Ryan stay in superhero shape for 15 years and has worked with Blake since she and the Deadpool 3 star began dating in 2011.

The parents-of-four have often publicly praised Don for the impact he's had on their respective mental and physical wellbeings, and the feeling is mutual. 

"They've been my favorite two people I've ever worked with my 25-year career," Don told E! News in an exclusive interview. "They've become family and they've single-handedly done more for me and my family than I can even explain."

And, as an early Christmas gift, the fitness expert is offering two programs—Deadpool 2 and Train Like Blake Lively 2.0—that feature the exact exercises Ryan and the Gossip Girl alum perform during their sessions. (And as an additional present: You can use the code E!20 for 20 percent off either program.)

But, even if you aren't planning to hit the gym this month, you can commit to other attainable wellness goals, as Don—who's also worked with Anne Hathaway, Sebastian Stan and Emily Blunt—is all about instilling healthy habits that will set a person up for consistency and success without sacrificing your favorite festive foods or setting an unrealistic resolution come New Year's Eve.

Here are six tips Don offered that will help set you up for success this holiday season, including eating before you go out and sleeping more. 

Listen, it's the holiday season and your time is limited due to all the festive parties, family time and, yes, food and wine. But that doesn't mean your wellness routine needs to suffer.

Blake Lively and Ryan Reynolds' trainer Don Saladino, who was worked with the couple for over a decade, shared tips on how to enjoy the holidays without depriving yourself. And while that may sound too good to be true, it's actually way easier and cheaper than you think, with Don stressing three absolute pillars of a wellness routine: Hydration, getting your steps in and quality of sleep. 

"I want them to be in a great shape and to feel good about themselves, but feel good to the point where they can go have it," Don said of his clients' approach to end-of-the-year fun. "I don't want anyone to worry during the holidays. Go have fun, but can you maintain those non-negotiables?"

So, Don advised to drink at least half your body weight in water every day, explaining, "Dehydration is one of the worst things for us." Then, focus on getting your steps in, with low intensity cardio proving to be beneficial for burning fat and your sleeping habits."

"And I haven't even put you in the gym yet," Don reminded.

But when it comes to that...

"Blake has never shied away from being strong," Don said, "and she lifts weights."

A fitness myth he was more than happy to debunk was the belief many women have that weight-lifting will cause them to bulk up like, well, Don himself. 

"I could put a woman on my exact same training program," he explained, "and we could be on it for the next five years and she'd probably have the body she's looking to have."

So that means women can definitely take part in Don's Deadpool 2 program, which utilizes movements Ryan performs in his workouts to get into superhero shape.

While cardio is important, Don said, "I actually urge women to start training more of how guys train," as strength training is beneficial for metabolism and muscle resilience.

"Give it a shot for the next nine weeks and see what happens," Don challenged. "Worst case scenario: You just might get a hell of a lot stronger, right?"

Don has one dare for you before you hit a holiday party: "I challenge you to eat more." Because, if your approach is to starve yourself all day, Don simplys asked, "Why the f--k would you do that?" 

The key, Don said, is increase your protein intake, over-eat vegetables and guzzle water leading up to an event.

"Let's say you've got a massive party next Saturday and you're like, 'I'm going all in,'" Don posed. "I would eat the good stuff all day long, because then you're gonna go into dinner, and that first bite is gonna hit your lips and not crush you because you haven't had anything in 10 hours. You're going to enjoy and you're not going to overeat and feel like s--t the next day."

So, rather than mind your calories, focus on shifting your mindset when it comes to indulging without overdoing it. Yes, you can have pie, but you don't need to have the whole pie every single day to enjoy yourself. 

"It's the mentality we fall into when we do that and then everyone just s--ts the bed," Don said. "It's like, 'Oh, well, I had this. I'm just going to give up and start in two weeks.' And then they end up putting on 10 pounds."

The idea of spending an hour doing the same workout every single day sound boring? It does to Don, too, which is why he often changes up modalities during sessions with his clients, based on their location, priorities or any injuries. And also because, he said, "It's gotta be fun." 

When training Blake and Ryan he efforts to expose them  "to different types of movements," he said. "I don't want to put either of them on the same program on day one and then on day 364, they're on the same program."

Plus, he continued, "Things are gonna change throughout the year. Unfortunately, injuries occur. Life occurs."

Like when Blake was pregnant, she added swimming to her workout routine because "TKTK." 

Spoiler alert: If you think your fitness and eating habits will magically transform when the clock strikes midnight on Jan. 1, 2024, you are setting yourself up for failure. 

"The reality is there's never been a human being ever that has been 100 percent consistent all the time," explained Don. Instead, focus on consistency, which means some sessions might be less intense than others, but you "are still working out," Don said, "and those are the people that have a high level of success."

Believing every workout needs to be a 10 on the intensity scale is "where most people screw up," Don said, "because they are used to watching movies like Rocky or these training montages where they're just watching someone get the s--t kicked out of them. So they're under this impression that they have to be the ones doing that also and if they don't do it, then there's suddenly a failure."

Practice doesn't make perfect, but it does make permanent, which is why Don prioritizes spending the first 10-15 minutes of a session "flossing" the body to assess how a client is feeling on that day and what they need to focus on during that workout.

"It's very individualistic, according to the person and the areas they're tight in," he explained. "That's what I do with everyone, from Blake to Ryan to whoever it is. We find out what areas probably aren't moving the way they need to be moving. And then we figure out ways to practice getting them better at those movements."

It may seem simple, but evaluate how you spend your time and how it makes you feel to figure out what works best for you.

 "We've all partied in our life, like we've had those Friday nights where you've gone out, you've hit it hard," Don said. "And you've had those Friday nights where you're doing a hot yoga class, you're going back to your apartment and ordering a healthy dinner and watching a movie in bed."After the latter, "you're waking up Saturday, like, 'Oh, God, this feels great,'” he continued. "You start looking at those habits and you're like, 'Well, where do I want to live?'"

That doesn't mean living a life without fun or French fries, especially if you are someone, Don hypothetically posed, who currently eats McDonald's every day.

"What we need to do is set a plan," Don said, advising to begin with just committing to cut back on indulging in whatever your vice is every four days. 

"I'm super happy about that level of improvement," he promised. "Stop trying to be perfect."

Deadpool 2 and Train Like Blake Lively 2.0 are available on Don Saladino's site and you can use promo code E!20 for 20 percent off.