If you’ve trained in a proper gym, or done your time in the military, you know the rule: kit has to earn its place. You don’t keep it because it looks cool. You keep it because it delivers.
That’s why we always raise an eyebrow when people ask, “Should I get a kettlebell or a sandbag?” Like it’s a binary choice. The truth? Most people swap one for the other without ever understanding the why behind either tool. And that’s where they go wrong.
Yeah, some of the exercises look the same. But dig a little deeper into the way they load, how they challenge your body, and what kind of strength they actually build, and you’ll see they’re very different beasts. And if you know how to use them right, both can be absolute game-changers.
Coming from a military background, you learn quickly that your gear has to be tough, adaptable, and ready to move when you need to. That’s why The55 was born. We took everything we learned in the field and built the ultimate training tool for the real world— chaotic, portable, full-body strength.
So let’s break down how to use these tools to get stronger and fitter.
The Origins of Sandbags and Kettlebells
Before we start slinging weight, let’s get into the backstory. Because these tools didn’t just show up yesterday!
Kettlebells: Forged for the Strongman
The kettlebell’s history runs deep, straight out of 18th-century Russia. What started as a counterweight for measuring grain quickly evolved into a tool for building powerful, workhorse strength. Farmers, soldiers, and strongmen all saw the potential in its off-centre design. It was (and still is) one of the simplest, most effective ways to train the entire body in one go.
Today, you’ll find kettlebells in every decent strength programme, from sports performance to special forces prep. They’ve earned their place, no question.
Sandbags: Built on the Battlefield
Sandbag training has been around for decades too. Originally used in military drills, construction sites, and even strongman events, sandbags have always tested more than just strength. They test grit, balance, coordination, and real-world control. No clean lines or ergonomic handles, just awkward weight and shifting resistance that forces your body to work with the chaos, not against it.
But not all sandbags are created equal.
The55: Born on the Battlefield, Built for Real Life
The55 Multi-Weight Sandbag was developed out of necessity, in a military deployment zone (Afghanistan), not a gym. Chris, our founder and Royal Army Physical Training Corps instructor, needed gear that could keep soldiers mission-ready with zero kit. One pillowcase. A couple of ratchet straps. And the first prototype of The55 was born.
What followed was years of refinement, testing, and evolution. The result? A multi-weighted, military-grade (used by UK armed forces) sandbag built for modern functional fitness. Packs small, hits hard, and adapts fast.
Why the Same Weight Feels Heavier: Understanding Centre of Mass
You ever pick up a kettlebell and think, “this feels heavier than a dumbbell”? You’re not imagining it. That’s the centre of mass doing its thing.
Most traditional weights (like dumbbells and barbells) have you gripping right at the centre of the load. Balanced, predictable, efficient. Not bad, just… straightforward.
Kettlebells flip that. The mass is offset (further from the handle), which forces your body to stabilise in new ways. It makes the weight feel heavier and moves differently through space. That’s why kettlebell swings, snatches, and get-ups hit so hard.
Sandbags Take It to the Next Level
Unlike a kettlebell, the handles of The55 sandbag have no weight in them at all. The load is entirely offset, sitting away from your grip. The result? Every rep is a fight for control. The weight pulls, shifts, drags and tries to throw you off balance. And depending on the size and how you fill it, the centre of mass can shift even further from your hands.
That unpredictability isn’t a flaw, it’s the feature. It builds raw, functional strength by forcing your body to stabilise under stress. Real strength, not just mirror muscles.
With The55, you’re not just lifting, you’re managing movement. Holding it in different ways (over the shoulder, bear hug, single handle, press-outs) completely changes the stimulus. That means you’re training not just different muscles, but different types of strength: crushing, pinching, supporting, and stabilising.
And yeah, your grip will feel it.
Kettlebell vs Sandbag Grip Training
You want stronger lifts, better control, and fewer injuries? Start with your grip. It’s the foundation of functional strength, and both kettlebells and sandbags force it to level up. But they do it in very different ways.
Kettlebells: Classic Grip Strength Builder
Kettlebells are no joke when it comes to grip. The offset load, thick handle, and explosive movements (like swings and cleans) demand serious forearm and hand engagement. And when you’re repping out snatches or holding on during a heavy clean and press set—your grip has no choice but to keep up.
That’s one reason kettlebells are a go-to for building crushing grip power.
How Sandbags Train Every Type of Grip
Now enter sandbags, and The55 in particular. You don’t just grip it. You wrestle it.
Because the handles are unweighted, and the load shifts with every move, you’re constantly readjusting your grip to stay in control. The further the mass sits from your hands, the harder you’ve got to work to hold on. Even basic movements like cleans, curls, or squats fire up your forearms in ways kettlebells can’t touch.
But it goes deeper than just one type of grip.
With The55, you’re not locked into a single grip style. You can train:
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Crushing grip (classic handles and heavy carries)
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Supportive grip (hug holds, over-shoulder carries)
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Pinch grip (off-set curls, arc presses)
- Wrist control (rotational movements, sandbag cleans)
Kettlebell vs Sandbag: Strength & Power
When it comes to getting strong, both tools hit hard, but they do it in their own way. It’s the difference between mastering form and mastering the unpredictable.
Kettlebells: Technical Strength, One Side at a Time
When it comes to controlled, structured strength, kettlebells shine. Their balanced but offset design makes them ideal for developing power through precision, especially in unilateral (one-sided) training.
You can isolate one side of the body, correct imbalances, and push serious weight without losing control of the movement. It’s calculated. It’s efficient. And it works.
And yes, lifting two 20kg bells is nothing to scoff at. That kind of load will build serious pressing, squatting, and pulling strength when done right.
Sandbags: The Power of Unpredictability
You’re not just lifting, you’re managing shifting, awkward, unpredictable weight. The load doesn’t just resist movement, it fights back. And that forces your muscles to engage through ranges and angles that traditional tools can’t touch.
It’s 3D strength. Functional power. The kind of resilience that pays off in real life, not just under gym lighting.
You’ll learn how to move with weight that doesn’t play nice, and that’s what makes you truly strong. Try pressing a 30kg sandbag overhead and tell us it’s not a different beast to a barbell.
Kettlebell vs Sandbag: Cost, Space & Efficiency
You don’t need a garage full of equipment to train hard. You need kit that earns its space, and kettlebells and sandbags both punch way above their weight here.
Kettlebells: Simple, But Add Up Fast
Kettlebells are compact, clean, and effective. But there’s a catch: one weight = one bell. Want to train across different loads? You’re buying a full set. That means more gear, more space, more spend. And suddenly your “minimalist” setup turns into a storage problem.
Sure, they last forever. But getting a full range isn’t cheap or particularly mobile.
The55: One Bag. Four Weights.
This is where The55 changes the game.
One bag. Four adjustable weight inserts. Unlimited ways to train. Whether you’re going light for speed or heavy for strength, you adjust mid-workout in seconds. No extra kit, no clutter, no faff.
And when it’s empty? Roll it up, chuck it in a suitcase, and you’ve got a portable gym that’s ready to go wherever you do.
- Takes up less space than your yoga mat.
- Costs less than a set of dumbbells.
- Delivers more variety than half the kit at your local gym.
Kettlebell + Sandbag = Power Combo (If You’ve Got the Room)
Look, if you’ve got space, budget, and the know-how, both tools together can be a killer combo. But if you want maximum function with minimal kit? The55 has you covered straight out the box.
Stronger Starts With Smarter
If there’s one thing to take from all this, it’s that real strength isn’t just about what you lift, it’s how, why, and with what.
Both kettlebells and sandbags are top-tier tools. But only if you understand what makes them tick. One is clean, sharp, and technical. The other is gritty, unpredictable, and unapologetically real.
At The55, we didn’t build just another sandbag. We built a tool forged from military necessity, designed to adapt with you, and tough enough to go anywhere.
So, if you’re ready to ditch the overhyped gear and start training with purpose, here’s what to do next:
Shop The55 Multi-Weight Sandbag – prefilled & Ready to go
Explore our 4 week functional training plan for beginners
Train harder. Train smarter. And don’t let your gear hold you back
FAQ: Sandbag vs Kettlebell Training
What is the difference between sandbag and kettlebell training?
Kettlebell training focuses on controlled, flowing movements with an offset load that’s consistent rep to rep. Sandbag training introduces shifting, unstable weight that challenges balance, grip, and core stability, making every rep unpredictable and harder to control.
Is sandbag training better than kettlebells?
It depends on your goal. Sandbags are better for building real-world functional strength, balance, and endurance under chaotic conditions. Kettlebells are ideal for technical lifts, cardio efficiency, and clean movement patterns. One isn’t better, they’re just built for different outcomes.
Are sandbags good for building strength?
Yes. Sandbags, especially multi-weight options like The55 — are excellent for building full-body strength. Their instability forces more muscle activation than stable weights, helping you build real-world power, control, and resilience.
Can sandbags replace kettlebells?
Sandbags can replicate many kettlebell-style movements (cleans, presses, carries) while adding more variability and instability. While they don’t fully replace the clean technique work of kettlebells, they offer a more versatile, travel-friendly, and functional alternative.
Do sandbags help with cardio training?
Yes, sandbag workouts are brutally effective for cardio. The shifting weight keeps your heart rate high and your body constantly adjusting, making it harder to “groove” the movement. It’s cardio with muscle behind it.