How Do Adjustable Dumbbells Work? Which System is Best?

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Written by Brian Sweet

Adjustable dumbbells work by releasing or “grabbing” the necessary weight held within the structure of the dumbbell with a simple action.

Adjustable dumbbells generally look like one large traditional, fixed dumbbell. The significant difference is that you can make adjustable dumbbells lighter or heavier in stepped increments with the touch of a button, dial or pin mechanism.  

Your average gym rat spends anywhere from an hour to three hours in the gym every single day – and they love it.

But how much better would it be if your gym was in your home? 

Home gyms are very popular, but they can be massively expensive to put together. The expense is all too real when you add up all the separate weights you’re going to need.

That’s why many people are investing in a good set of adjustable dumbbells to compliment the area of strength training in their fitness regime.

A range of seperate weights take up more space than a single (or 2) adjustable dumbbells and will be more expensive.

These babies get the job done in one easy solution. 

What is an Adjustable Dumbbell?

An adjustable dumbbell set includes two dumbbells with adjustable weights. Sounds pretty simple and straightforward, right? 

That’s because it is!

For quick and easy understanding, we can categorize adjustable dumbbells into two different types: plate-loaded adjustable dumbbells and selectorized adjustable dumbbells

We’ll take a look at how each of these dumbbells works, respectively. But if you’ve seen enough you may want to…

Plate-Loaded Adjustable Dumbbells: How They Work 

These adjustable plate-loaded dumbbells are self-explanatory. With these dumbbells, you can adjust the resistance by adding or subtracting weight plates. 

These types of dumbbells usually have one of two locking mechanisms: 

  • Spin locks
  • Quick locks

Spin-lock adjustable dumbbells feature a nut-and-bolt type situation. You slide your plates onto one side and lock them into place using a spinning lock that you screw into place like a very large nut. 

Some people like this system because it’s affordable and easy to use, but your lock is less secure than most adjustable dumbbells. 

On the flip side, you have quick-lock adjustable dumbbells. This adjustable dumbbell also has weight plates, but the locking mechanism is different.

Rather than a lock that screws into place, these dumbbells have partially threaded pins that you insert and turn just a half rotation. 

This system locks into place, so you don’t have to deal with your plates coming loose and making a ton of noise and movement. However, quick-lock systems tend to be more expensive than spin-lock weights. 

In both of these cases, you will still need a number of loose weight plates.

Not perfect, but still a more convenient method than the traditional dumbbells.

Selectorized Adjustable Dumbbells: How They Work

Many people who regularly train with weights believe that the best adjustable dumbbells are selectorized.

These dumbbells take all the grunt work out by removing the need for loading and unloading plates.

You can adjust the weight of these dumbbells simply by turning a knob, or dial, or by moving a selector pin into the desired position.

Each of these mechanisms lets you quickly switch from plate to plate or several plates already included in the frame of the dumbbell set. The change is automatic, so there is no physical loading or unloading of the weight plates.

No time is wasted between sets while you find the right plate, load and fasten the lock. It’s fast and easy, which is what you want in an efficient and effective workout.

What Are the Benefits of an Adjustable Dumbbell?

It’s the way adjustable dumbbells work that many people from serious bodybuilders to the everyday person wanting to maintain their strength choose them.

Although initially, more expensive the benefits below outweigh this outlay and many people prefer these more modern adjustable dumbbells for their home gyms over traditional, fixed-weight dumbbells. 

They Save Space 

One of the most significant benefits of using adjustable dumbbells over traditional sets is that they take up a lot less space. Usually, if you want a full range of weights to select from, you have to keep buying different-sized fixed dumbbells.

But adjustable dumbbells include a wide range of weights in one small package, which saves you a ton of space. That’s why they’re ideal for home gyms where you might not have room for a big weight rack. 

They’re More Affordable 

In many cases, adjustable dumbbell systems save you money. 

Anyone who has built a home gym knows how expensive weights can be. If you can buy weight for a dollar per pound, you’re lucky.

It might be easy from the start to purchase one or two weight sizes that you need, but as you get used to the world of strength training you’ll want more variety and so more weights. 

Those costs add up quickly. 

Some exercises require heavier weights, while others use lighter weights. You might need a heavier dumbbell for leg exercises but a lighter weight for curls. 

Instead of buying a few different sets, you can use one system and save money. 

Easy to Transport 

Whether you feel like exercising outdoors or want to work out at a friend’s house, you can take your adjustable dumbbells with you. 

Imagine how much of a hassle it would be to transport several different fixed dumbbells. With an adjustable set, you can grab the whole thing and move it wherever you need it to go. 

Smaller Adjustments

Unless you’re working out at a large gym that has all the dumbbells you could ever want or need, you likely don’t have access to weights with small increments.

Typically, you can expect a small dumbbell set to adjust by 5, 10, or even 15 pounds. More weight can be added easily in small amounts.

True athletes understand how critical that small half-pound or single-pound increment can be for training, and a lot of adjustable dumbbell sets let you do that with in-between weights. 

Some Downsides To Adjustable Dumbbells

You may have guessed, I’m a big fan of an adjustable dumbbell but there are some considerations that are worth mentioning.

Weight Range

If you want to use a wide range of weights it may not be accessible with an adjustable weight system. The way adjustable dumbbells work means that there is a minimum weight which is the cradle to support the weight plates.

The upper weight is more likely heavier enough although there are different models for differing upper and lower weights.

For example, Bowflex has 3 models.
552 – range, 4.5 to 43 lbs
560 – range, 5 to 60 lbs
1090i – range, 10 to 90 lbs

Handling Adjustable Weights

There is another issue that we found significant. The way adjustable dumbbells work means there is always a frame for the plates whether loaded or not.

This means that at even a light weight the length and overall dimensions of the frame are the same. The length of the weight may be most important depending on the type of exercises employed.

Which Adjustable Dumbbell System is the Best?

There are tons of adjustable dumbbell systems on the market today, and you want to know you’re getting the best for your money. We’ve picked our top three favorites for you listed below with a little bit of info to get you started. 

PowerBlock Elite Dumbbells

The PowerBlock Elite Dumbbells is a system like none other. It’s definitely our favorite and is the preferred choice of the Fitness Blender team.

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The weight ranges from 5 to 50 pounds per dumbbell using a secure magnetic pin. Choosing your weight is super easy, and the weight increments are enough to replace as many as 16 pairs of dumbbells.

We also love their square shape, which makes them perfect for a wide range of workouts and placements. And they won’t roll away. 

The Powerblock and Bowflex systems are two of the most popular adjustable dumbbells available and we have written a comparison guide here.

Bowflex SelectTec 552 Adjustable Dumbbells

Bowflex dumbbells have been a market leader for many years and their adjustable weights like the Bowflex SelectTech 552 adjustable dumbbells make for an excellent equipment choice.

Each dumbbell in this two-piece set adjusts up to 52.5 pounds. The first 25 pounds adjust in 2.5-pound increments for easy fine-tuning. 

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The dial system lets you choose your weight quickly and easily, letting you focus on your workout. 

NordicTrack Speed Weights

The NordicTrack Speed Weights are sleek and stylish dumbbells that come out to perform. These dumbbells range from 10 to 55 pounds and feature varying increments, including 2.5 pounds from 10 to 15 and then 5 pounds from there on up. 

Pair of NordicTrack speed adjustable dumbbells

The locking pin makes it easy to select your ideal weight and keep your workout moving. 

Final Thoughts

Having a home gym is definitely convenient, and makes working out more accessible and quick. But your home gym is only as good as the equipment you purchase.

Adjustable dumbbells make an excellent addition to any workout space. They’re easy to use, take up little space, and are cost-effective. You can’t go wrong with any of our choices, either.

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Mad keen runner of old. Now just mostly mad. But mad keen on researching the best and latest fitness-related information and products for a healthier and fitter midlife. Over 50 - most definitely. Qualified in Australia as a PT in Sports & Recreation.

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