Kate Upton in Two-Piece Workout Gear Shares Weight Lifting Workout

Kate Upton is 31 and in the best shape of her life, thanks to the hard work she puts in with long-time trainer Ben Bruno. Bruno posted a video of Upton wearing a purple and pink exercise outfit, doing strength-training exercises using a 40-pound dumbbell. Bruno explains she actually invented the move herself. "Here's @kateupton casually pressing a 40-pound dumbbell using the '2 up/1 down' technique. We actually call this the 'Kate Press' because 1) she's really good at it and 2) she unknowingly 'invented' it like eight years ago. We were doing regular 1-arm overhead press but overshot the weight a little bit, and she reflexively used two hands to press the weight up," he captioned the post. Bruno has spoken in detail about how Upton transformed her physique—here's how she did it.

Upton does a circuit-based strength training workout with Bruno five times a week. "We generally start off the workout with a series of strength exercises done in circuit fashion, followed by work with the sled," Bruno tells PEOPLE. "Structuring the workout in this fashion provides a cardio effect even though we aren't doing traditional 'gerbil' cardio, like using a bike or treadmill." Here is an example of her exact routine, as told to the magazine:

"Warm-up:

Brief stretching and foam rolling

Lateral band walks

Workout:

A1. Landmine squats, 3 sets of 8

A2. Squat jumps, 3 sets of 8

A3. Hip thrust countdown, 3 sets of "5 to 1" – Start with five reps followed by a five-second isometric hold at the top. Then do four reps followed by a four-second hold, then three, then two, then one, for a total of 15 reps.

A4. Inverted rows, 3 sets of 12

B1. Sled push/ Explosive sled rows, 3 sets – push the sled down, and row back

B2. Ab wheel rollouts, 3 sets of 12

B3. TRX triceps extensions, 3 sets of 12

Notes: A and B exercises are done as paired sets, so do all the A exercises before moving on to the B exercises.

Cool down:

Stretching and foam rolling"

Upton's diet is crucial to reaching her fitness goals. "It's lean protein at every meal, and really limiting sugar and processed foods," Bruno tells PEOPLE. "She does eat treats every once in a while, like everybody does. That's totally fine. You just pick up where you left off, and keep on healthy eating. Her favorite treat is doughnuts. It's not all the time, but life's too short to not have some fun stuff every once in a while!"

Upton partnered with wellness brand Found Active to launch a line of clean skincare and wellness products for women. "I always believe in enhancing who you are and looking and feeling your best," she tells Shape. "I hope that these products fit into your daily routine instead of you changing your life for them. I want women to be who they are, enjoy their lives, and have the energy to be themselves."

Upton believes makeup should enhance natural beauty and inspire confidence. "I feel like makeup is so nice if you use it in a way that makes you feel better about yourself. But there are also so many times when you're putting on makeup to cover up or change different ways of your face," she tells PEOPLE. "I see it more and more with social media. It creates a negative mental relationship with yourself that you feel you should change. So I think being makeup-free stands for loving myself how I am. Although I do love makeup, I appreciate what being makeup-free means." 

Upton says for her, feeling beautiful is not a constant. "It's always a journey because we're human," she tells PEOPLE. "You feel stressed some days and you feel overwhelmed or tired. I think just going back to appreciate the connections we have — the family, the friends and putting how I feel beautiful on my relationships and on my relationship with myself. [That] is how I feel most beautiful."