Kristin Cavallari Reveals the Summer Workout Routine That Transformed Her Body

When Kristin Cavallari says she’s never looked or felt better, you pay attention. The secret behind her transformation? Nashville-based trainer Kevin Klug, who’s revolutionizing fitness with his elite mobile personal training business that delivers a full-size, personal gym right to their client’s door.

The founder of Klug Fitness has a no-nonsense approach to building sustainable strength. Before training with him, Cavallari explains, “I did not understand how important heavy weight is. Since we’ve been working out together, I’ve increased my weight, eating more protein, and eating carbs again.” 

On Let’s Be Honest, Klug shares what actually transforms bodies, what twitch movements are, and the muscle groups he focuses on and the ones he doesn’t—you might be surprised! He also explains why you don’t need to workout every day to get that summer body. Who else is over crash diets and punishing cardio sessions?

Designing a fitness program around your goals (And yes, a summer body can be your goal!)

Before launching Klug Fitness in 2016, Klug earned his stripes on the road with country music royalty. After years touring with Lady A, Sam Hunt, and Luke Combs, he spotted a gap in the market: high-end fitness that comes to you. He bought a van, loaded it up with 700 pounds of equipment, and started his mobile gym concept. He has since expanded to six vans and seven trainers who deliver personalized workouts without clients ever setting foot in a traditional gym.

Klug explains that his approach attracts celebrities because of the ruthless focus on fundamentals paired with personalization. He says that the basics look similar for everyone, but he designs programs around what clients actually enjoy since sustainability comes from finding what you’ll stick with.  

Klug is a big believer in sprinting to work the twitch muscles, which creates lean muscle: “Look at a track athlete. They look lean and thin. Most people want that look. We are going to implement plyometrics, jumping, and sprinting as well.”

Protein + weight lifting = the workout formula transforming bodies

If you want that summer body, it’s important to prioritize nutrition. Nutrition matters when it comes to both building and maintaining muscle. But your nutrient intake for the two goals will look different. Klug advocates for creatine, which helps support lean muscle mass development, cognitive function, and recovery.  

Most women don’t eat enough protein, which is crucial to build muscle. Building muscle also requires more calories than people realize. So if you’re not seeing results, you might need to adjust your protein intake. 

Since working with Klug, Cavallari has embraced heavier lifting and twitch movements. When she worked with other trainers, time at the gym was “a gab session.” Cavallari says, “Before it was like, ‘Let’s just shoot the sh*t and hang out.’ Also, I used to lift 10 to 15 pounds. The first time we worked out, you gave me 25 pounds. It is heavier than I have ever done before. It is pushing myself.”

But Klug is clear that lifting heavier is not the only sign of improvement. “Progress does not always mean heavier weights,” he says. Sometimes it’s decreased rest periods, additional reps, or improved form—all signals your body is adapting. 

Kristin Cavallari’s summer workout routine

Klug says it’s important to keep your program simple to master fundamental movements and build consistent strength. However, you still need effort and intensity during main lifts, regardless of individual goals.

Klug’s workout program for Cavallari follows a strategic three-block structure:

Block one might begin with a 10-minute dynamic workout featuring medicine ball tosses or sprints to activate the twitch muscles. This leads into the session’s main movement, which will be the hardest thing she’ll do the entire workout. Examples include a leg movement, a jumping movement, and a back movement. 

The second block of the program shifts to less demanding but targeted exercises, typically featuring lighter single-leg movements to isolates specific muscle groups. Klug often incorporates a core work and upper body exercises into this block, so there are three movements.

Block three becomes completely personalized based on individual needs. “We will work on what we need to work on—mobility, shoulders, or back. It really depends on the client,” Klug explains.

The sustainability secret

As summer approaches, remember that the body you want comes from strategic intensity, adequate recovery, and a sustainable approach—not punishment or restriction. For healthy fitness all year round, learning the fundamentals of simple exercise circuits is critical. Klug’s goal when training clients is to teach them simple movements that they can implement when they’re on the go. “With any client, they all travel,” Klug says. “If they go to a gym on their own, I want them to look forward to seeing a gym. We keep it simple enough that they know what to do when they get there. Simplicity also allows them to get good at it.”

Some basic movements that everyone should do: squats, hinges, single-leg movements, a press movement (like pushups or a bench press), and a pull movement (like a row or a pull-up).

Healthy habits and consistency are the foundation for better health. Klug, who works out two to four times a week, says it boils down to simplicity: “The biggest thing is what are you doing outside of those hours. I go on walks every night with my wife and kids. How active you are outside of working out matters just as much as what you do during an hour at the gym.”