Kate Hudson Works Out In Greece with an Aqua Bag

Get the scoop from her trainer on why it's such a killer move for challenging your core strength and stability.

While scrolling Instagram lately, you've likely come across plenty of travel porn — and that includes posts from Kate Hudson, who's on a dreamy Mediterranean work-cation with her family in Greece, where she's filming Knives Out 2 (coming in 2022). In between snapshots of her strolling the beach and lounging by the pool, Hudson's been posting some seriously advanced workout videos, including one of her practicing her push-up form and another of her crushing some TRX core exercises.

In her latest video, Hudson is working out — in Hoka One One Clifton 7 Sneakers (Buy It, $105, zappos.com) and a matching Fabletics bike shorts set (Buy It, $90 or $50 for members, fabletics.com) — with certified trainer and strength coach Brian Nguyen. (Also peep her partner Danny Fujikawa, who's doing some solid hip thrusts in the back of the video.)

But even more impressive than her dedication to training on vacation is the actual workout she's doing — and there's a good chance it's something you've never seen before.

In the video, Hudson is swinging a Bulgarian bag-shaped JoyPlus Aqua Bag (Buy It, $40, amazon.com) — sort of like a sandbag that's instead filled with water — around her body without skipping a beat. "This gives 'staying centered' a whole new meaning for me 😜 First time taking this for a ride, definitely not the last 🌪," she wrote in the caption.

Nguyen says he snagged one of the bags off Amazon when he was trying to figure out how to weight train with Hudson while traveling with her to Greece. Because you can empty it and roll it up, it's the perfect piece of equipment to travel with; it can even fit right into a backpack, he tells Shape. Then you can pump it full of air and water, varying the amount of weight inside depending on how much water you add. His particular bag — which he mentioned may be based on the Onnit HydroCore Bag (Buy It, $110, onnit.com) — can hold up to 30 pounds of water.

Nguyen reposted Hudson's video, shedding a little more light on why he has her training with the aqua bag — which weighed a hefty 20 pounds when she was slinging it around.

"I believe it's crucial to incorporate rotational exercises to all athletic training programs. In other words, work in the transverse plane is a must," he wrote. FYI, moving forward and backward happens in the sagittal plane; moving side to side happens in the frontal plane; and moving in rotation happens in the transverse plane, according to the American Council on Exercise. It's important to train your body in all planes of motion so that it's ready and able to handle all those different types of movements in everyday life. (See: Why You Should Add Lateral Moves to Your Workout)

Beyond that, working on rotational exercises "totally improves the neuromuscular connection between the core and the rest of the body," wrote Nguyen. "I mean, check out Kate's movement in this tornado drill while she digs for speed: her core is fighting for more integrity (stability) while her mobile joints (hips and shoulders) seem to unlock more with every turn!"

While many core exercises involve moving your body to engage your abs (think: crunches), this drill is all about keeping your core solid — which is, actually, the true goal of core work, says Nguyen. "Real core training is about preventing the gross movements," he says. (

"Moreover, working with rotational movement not only prepares us for the forces of real life but also increases our capacity for greater power and more explosiveness throughout one's range of motion: true athleticism, that is," he wrote in the caption.

That's exactly why you probably shouldn't go try this at home — Nguyen says he's been working with Hudson for six weeks on building core stability, starting with anti-rotation moves (such as planks and Pallof presses, which you can do with a resistance band or a cable machine) to work her way up to this sort of dynamic power move. "We're taking all this anti-rotation and creating movement and power upon that rotation control and integrity," he continued. "Because without it — if you haven't practiced the feeling of rotational integrity and you go right to the sandbag — that's how you hurt yourself."

You can do a lot of other things with the aqua bag that are a bit more beginner-friendly. (In addition to this Bulgarian-bag shape, you can also buy round aqua bags that are similar to medicine balls or cylinder-shaped bags akin to traditional sandbags.) You can load it onto your back for back squats or lunges, use it for bicep curls or overhead presses, or do deadlifts or bent-over rows. You can also perform other dynamic movements with it like kettlebell swings.

Because the water inside can slosh around, it adds a challenging balance element to any move. Nguyen says he loves having Hudson do walking lunges with the bag along her shoulders, adding a bit of a sideways lean toward the side with the rear foot — "the water spills to that side and, oh my god, it lights up your core because, without the front leg, your body totally wants to fall over," he says.

For Hudson, the goal of all this core work is, sure, to look 🔥🔥🔥 in her new movie — especially after giving birth to three kids, her most recent in October 2018 — but "her biggest motivation is to find her strength as the strongest version of herself that she can be," says Nguyen. "She's always been very strong... and she's done all sorts of things for workouts, but in terms of formal strength training, this is kind of a new thing for her. Now, she's lifting a little more weight than she's ever done and she's doing a lot more motor control work. Motherhood takes its toll on the body — carrying babies and carrying the pains of motherhood on top of that — so as such a beautiful mover in her pre-baby times, she was really not feeling like herself. For her, it's really about finding this strongest version of herself again so she can be there for her kids."