I recently got my hands on the reax superfly 2, and honestly, it's not your average piece of gym equipment. If you're used to static weights, this thing is going to throw you for a loop—literally. I've spent the last few weeks messing around with it, trying to figure out if the hype around "reactive training" is actually worth the investment or if it's just another fitness fad. After a few sessions of nearly tipping over because of the unpredictable weight shifts, I think I've got a pretty good handle on what makes it tick.
Most of us are used to the gym being a very controlled environment. You pick up a dumbbell, it weighs 20 pounds, and it stays 20 pounds throughout the entire movement. But the reax superfly 2 doesn't play by those rules. It uses what they call "Sudden Dynamic Impulse" technology, which is a fancy way of saying there's stuff moving around inside that tries to knock you off balance. It's basically a fight against physics every time you pick it up.
What Exactly is This Thing?
If you haven't seen one in person, the reax superfly 2 looks a bit like a futuristic, soft-sided weight. But the magic is on the inside. It's filled with a mix of liquid and metal spheres that slosh and slide around as you move. This means the center of gravity is constantly changing.
Think about it like this: have you ever tried to carry a half-full gallon of milk while running? The sloshing makes it way harder to stay steady than if it were a solid block of wood. That's the core principle here. It forces your muscles—especially those tiny stabilizer muscles we all ignore—to wake up and do some work.
Why Your Traditional Workout Might Be Missing Something
Don't get me wrong, I love a good heavy squat rack session. But there's a massive difference between being "gym strong" and being "life strong." In the real world, things aren't balanced. You trip over a curb, you catch a falling kid, or you lunge to grab a grocery bag that's ripping. These are all reactive movements.
That's where the reax superfly 2 shines. It mimics that unpredictability. Because the weight is shifting mid-air, your brain and nervous system have to communicate faster with your muscles to keep you from falling over. It's a total neuromuscular workout. After twenty minutes with this thing, I felt a kind of fatigue in my core that I just don't get from standard crunches or planks.
The Science of "Sudden Dynamic Impulse"
I know, it sounds like something out of a sci-fi movie. But the idea behind SDI is pretty straightforward. Most injuries happen when we aren't prepared for a sudden change in force. By training with the reax superfly 2, you're essentially "pre-habilitating" your body. You're teaching your joints and ligaments how to handle sudden shifts in load.
It's not just about getting bigger biceps; it's about making your body more resilient. The fluid inside the Superfly 2 doesn't move in a predictable pattern. It's chaotic. And because it's chaotic, your body can't just go on autopilot. You have to stay focused on every single rep.
Putting the Superfly 2 to the Test
I decided to swap out some of my regular movements with the reax superfly 2 to see how it felt. First up were basic lunges. Normally, lunges are a breeze for me. But holding the Superfly 2 at chest height changed everything. As I stepped forward, the liquid inside shifted, pulling me slightly to the left. My right glute and my entire core had to fire instantly to keep me upright.
Then I tried some overhead presses. This was probably the most humbling part. Usually, I can press a decent amount of weight without thinking about it. With the reax superfly 2, the weight would shift just as I reached the top of the movement. I could feel my shoulders working overtime just to keep the weight from drifting behind my head. It turns a boring shoulder press into a full-body stabilization exercise.
Is It Better Than a Kettlebell?
A lot of people ask if this is just a glorified kettlebell. I get the comparison, especially since kettlebells have an off-center mass. But a kettlebell is still a solid object. Once you learn the swing, you know exactly where the weight is going to be.
The reax superfly 2 is different because the weight moves inside the device. You can do the exact same movement twice, and the fluid might move differently each time. It's that lack of repetition that makes it so effective for athletes or anyone who wants to improve their coordination.
Who Is This For, Anyway?
To be honest, if you're just looking to get as "swole" as possible and you only care about bicep peaks, this might not be your primary tool. But for everyone else? It's a game-changer.
- Athletes: If you play sports like soccer, basketball, or MMA, your world is full of sudden movements. The reax superfly 2 is probably the closest you can get to sport-specific chaos in a gym setting.
- Physical Therapy: It's great for rehab because it forces stabilization without needing massive amounts of heavy weight. It's more about control and reaction than raw power.
- The Bored Gym-Goer: Let's face it, doing the same three sets of ten every week gets old. This thing makes working out feel like a challenge again. You can't zone out while using it.
Build Quality and Durability
One thing I was worried about was whether this thing would leak or burst if I dropped it. I mean, it's filled with liquid and metal balls, right? But the construction of the reax superfly 2 is surprisingly beefy. The outer shell is a high-grade, flexible material that feels like it can take a beating.
I've dropped it (mostly by accident) and even done some light slams with it, and it hasn't shown any signs of wear. The handles are integrated well, and the grip is comfortable even when your hands get sweaty. It feels like a premium piece of kit, which is good because it isn't exactly cheap.
Portability and Storage
Another plus is that it's relatively soft. Unlike a 20-pound iron plate that will crack your floor tiles if you're not careful, the reax superfly 2 is a bit more forgiving. It's also easier to toss in the back of a car if you want to take your workout to the park. It doesn't roll away as easily as a medicine ball, either, thanks to its slightly flattened shape.
The Learning Curve
I should probably mention that there is a bit of a learning curve. The first time you use the reax superfly 2, you're going to feel a bit clumsy. That's okay. That clumsiness is actually your brain trying to figure out how to compensate for the shifting weight.
Don't start with the heaviest one available. Start lighter than you think you need to. Once you get the "rhythm" of the sloshing, you can start increasing the intensity. It's less about how much you can lift and more about how well you can control the movement.
Final Thoughts on the Experience
After spending a good chunk of time with the reax superfly 2, I'm a fan. It's rare to find a piece of equipment that actually feels like it's doing something new. Most "innovative" gym gear is just a different handle on a cable machine, but this is a different philosophy of movement.
It makes me feel more "connected" to my body. You can't just go through the motions. You have to be present, you have to react, and you have to be ready for the weight to move when you don't expect it. It's frustrating at times, but in a way that makes you want to get better.
So, if you're looking to shake up your routine—quite literally—the reax superfly 2 is worth a look. It's tough, it's effective, and most importantly, it's actually kind of fun to use. Just don't be surprised if it makes you feel like a beginner all over again for the first ten minutes. That's just the "fly" part doing its job.