Take one look at Christmas Abbott’s chiseled body—arms that could put The Rock in a sleeper hold, bona-fide six-pack abs—and you’d have every right to believe she’s a comic book superhero incarnate. If you know a bit about the five-foot-three phenom, it’s probably that she’s NASCAR’s first female pit crew member. Or you’ve seen her as a CrossFit frontwoman, gym owner, and nationally ranked Olympic lifter capable of executing lifts only pros should try.

Now she’s got a book. The Badass Body Diet, out from HarperCollins, is surprisingly filled with basic exercises like squats, jumping jacks, and lunges, rather than the more advanced moves she’s clearly mastered—a choice, she says, that has to do with the ghost of Christmas’ past.

“When I was 22, I took a job as a civilian contractor in Iraq,” Abbott says. “I was embedded with the military. I was actually smoking and drinking and not living a healthy lifestyle, and some incoming rockets into my camp one morning made me reconsider my life choices.” First she quit smoking, then she started working out.

“I started off with the basics. I started off doing pushups and squats and lunges,” she says. “You can’t jump into something and not expect to go through the fundamentals first.” That’s the philosophy on which she built The Badass Body Diet. “I wanted potent fundamentals you can always go back to. These movements are easy to execute and fun to do,” she says.

The moves alone might not get you Christmas-level cut, but you have to start somewhere. So start here. Below, Abbott shares three of her favorite strengthening moves straight from her book. “Use good technique,” she says, “and intensity. You want to get the heart working hard.”

Bench Dips

Where It Burns: This move primarily works your triceps but also engages your forearms, shoulders, chest, abs, and lower back.

How To: You’ll need a stool, bench, chair, or box. Just make sure it’s stable. Sit down on the stool. Place your hands on either side of your body, grasping the bench, palms down. Push your hips off the stool, positioning your butt as close to the stool as possible.

Keeping your legs at a 90-degree angle to the floor, lower your body to the floor. Then press up, locking your elbows to put tension on your triceps at the back of your arms.

Blunders to Avoid: Make sure you dip down as far as you can lower yourself. In fact, the lower you go, the better you target the working muscles that are involved in this exercise. Keep your back as close to the object as possible. Don’t let your hips pull you away.

Tip: To increase the difficulty, walk your feet out farther to perform the exercise, or elevate one leg as you execute the move.

Jumping Jacks

Where It Burns: In your thighs, stomach, and calves.

How To: Begin in standing position, with your feet about a foot apart and your arms at your sides.

Simultaneously raise your arms overhead and spread your legs out to the sides. Land on the balls of your feet with your legs apart and with a slight bend in your knees to absorb the shock.

Clap your hands over your head. Immediately jump again and return your arms and legs to the starting position to finish one full jumping jack. Repeat continuously for the suggested number of repetitions without pausing between jumps. And don't forget to breathe!

Blunders to Avoid: Do not bend your elbows; keep your arms straight throughout the move.

Tip: Use jumping jacks as a cool way to squeeze some heart-pumping cardio into your day without having to go to the gym or spend hours exercising. Jumping jacks can be performed during breaks, while watching TV, or virtually anywhere.

Single Leg Squat

Where It Burns: Glutes, hips, and thighs.

How To: Use a sturdy chair or bench and place it behind you. Take a step away from the bench. Place your back leg on the bench, toe down. Stand straight up, with erect posture.

Flex your hip and squat down toward the floor. Hips should go back and down. Try to get your hip crease to come below the top of your knee. Keep your stomach tight. Continue squatting for the suggested number of repetitions.

Blunders to Avoid: Your knee should not drift over or past the toe. Also, try not to round your back during this exercise. When your lower back is rounded, you’re more susceptible to injuries such as a bulging (herniated) disk.

Tip: If you slow down during the descent, you’ll stimulate greater muscle toning and development, particularly in your booty and thighs.