Progressive overload works best when you can add a little weight often. Most adjustable dumbbells jump in 2.3 to 2.5 kg steps across 15 to 16 settings; the BrainGain SmartBells Pro jump 1.5 kg across 26 settings. Smaller jumps give you more usable progressions before you stall, which matters most on pressing lifts where a big increase costs reps. For committed lifters training several times a week, increment granularity is a serious-lifter feature, not a budget one.
Choosing an adjustable dumbbell, most people look at the top weight first. That is the wrong number to lead with. What shapes your progress over months is not the ceiling, it is the size of the step between settings and how many of those steps sit in your working range. Here is why the small jumps matter more than the big number.
Why Small Increments Matter
Strength goes up in small steps. When you add weight, your body needs a jump it can actually adapt to, not a leap that buries the set. On big lifts like a goblet press or floor press, the difference between a 1.5 kg and a 2.5 kg jump is often the difference between hitting your target reps and missing two of them. Miss enough sessions and progress stalls, even though your strength was ready for a smaller step.
This is why the size of the jump matters as much as the top weight. A dumbbell that only moves in 2.5 kg blocks forces every increase to be large, whether your lift is ready or not. A set that moves in 1.5 kg steps lets you nudge the load up at the pace your body actually adapts.
1.5 kg vs 2.5 kg: The Maths of a Stall
Take a working dumbbell overhead press at 20 kg per hand. Here is how the next four increases look on each step size.
| Increase | 1.5 kg steps (SmartBells Pro) | 2.5 kg steps (typical) |
|---|---|---|
| Start | 20.0 kg | 20.0 kg |
| Step 1 | 21.5 kg | 22.5 kg |
| Step 2 | 23.0 kg | 25.0 kg |
| Step 3 | 24.5 kg | 27.5 kg |
| Step 4 | 26.0 kg | 30.0 kg |
| First jump | ✓ about +7.5% | about +12.5% |
| Worked example. A 1.5 kg step is roughly a 7% jump at 20 kg; a 2.5 kg step is roughly 12%. The smaller jump is far easier to absorb week to week. | ||
The lifter on 1.5 kg steps gets two extra usable loads inside the same range, and each jump asks less of the body. On the 2.5 kg path, the same lifter is pushed to 30 kg in four moves and is more likely to stall before getting there.
Why 26 Settings Beats 15 or 16
More settings is not about the top number. It is about how many usable rungs sit between your warm-up and your heaviest working weight. The SmartBells Pro 41.5 kg give 26 rungs to the top. A 15- or 16-setting dumbbell covers a similar span with fewer stops, so each step is bigger and you have fewer places to land when a lift is progressing slowly.
For a lifter running different rep ranges, warm-up sets, top sets, and back-off sets, those extra rungs mean you can match the load to the set instead of rounding to the nearest big block. We put the full reliability case for the SmartBells through four stress tests in our 90-day teardown against the NÜOBELL and Bowflex 552.
Granularity Is a Serious-Lifter Feature
Fine increments often get filed under "beginner" or "budget." That has it backwards. The lifter who benefits most from a 1.5 kg jump is the one who has trained long enough that 2.5 kg leaps now cost them reps. Beginners can add weight fast because they are far from their ceiling. Committed lifters live near theirs, and that is exactly where small steps keep progress moving.
Who This Is For
Strength training is still a minority habit: only about a third of adults do any muscle-strengthening work twice a week or more, according to U.S. national health survey data. The people who do, and who keep at it, are the ones step size affects most. In BrainGain's own survey of EU buyers, the feature owners named most often as the deciding factor was exactly this: the small 1.5 kg steps that let them keep adding weight without stalling, all the way to 41.5 kg per hand.
The SmartBells were also checked by the independent institute SaferBuy, which scored the set 95/100 and verified its trust badge, including a 100/100 for matching its listed weight and increments. You can read the full SaferBuy report here.
BrainGain’s kit has also drawn outside recognition: Men’s Fitness named the SmartBells 24 kg its Best-Value adjustable dumbbell, calling the adjusting mechanism “faultless.”
See the Increments in Action
If you want to see how quickly the weight changes between sets, this hands-on review from the HomeGymPhysique channel runs through the mechanism.
If progression is your priority, you want:
- The smallest usable jump you can get, around 1.5 kg.
- The most settings inside your working range, not just a high ceiling.
- Headroom to keep climbing, up to 41.5 kg per hand on the SmartBells Pro.
Frequently Asked Questions
How many weight settings do you actually need on adjustable dumbbells?
What weight increments are best for progressive overload?
Are more weight settings worth it?
Do the SmartBells Pro go heavy enough for serious lifters?
Adjustable dumbbells or a full set for progressive overload?
- Men’s Fitness, BrainGain 24 kg named Best-Value adjustable dumbbell. mensfitness.co.uk
- U.S. Centers for Disease Control and Prevention, National Center for Health Statistics, Exercise or Physical Activity. cdc.gov
- SaferBuy independent test report, BrainGain adjustable dumbbells, 95/100 (October 2025). saferbuy.fr
- BrainGain EU buyer survey 2026.
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