Dumbbell vs Barbell Bench Press: What the Research Shows

The dumbbell bench press and the barbell bench press look like near-identical lifts, and the research treats them that way. In the studies below, the chest and front shoulder muscles worked to a similar degree on both, and rep counts at matched loads were close. The differences that did show up were small, short-term, and in supporting muscles.

No study we found tracked muscle growth or strength over months with one version against the other. So this article sticks to what was measured, flags where we are making a suggestion rather than reporting a finding, and shows how to keep a clean record if you use both.

Is the dumbbell or barbell bench press better?

Neither came out ahead in the research we reviewed. Muscle activity in the main pressing muscles was similar, and reps at equal loads were close. The rest comes down to practical factors such as loading, equipment, and which version you can progress steadily.

That is a narrower claim than it sounds. The studies are small and acute, which means they measured what happened in one or a few sessions. They tell you how hard muscles worked or how many reps people completed. They cannot tell you which lift produces more muscle or strength over a year. If you have read barbell vs dumbbell training in general terms, the bench press is a good example of how little separates them when you look at the data.

What do EMG studies show about the two lifts?

Surface electromyography (EMG) records electrical activity from the muscle, and the two studies here point the same way for the chest and front shoulder but differ on supporting muscles. EMG is a measure of activation, not of growth, so it is best treated as a clue.

Welsch, Bird and Mayhew (2005) had 12 college-age men and women with varied lifting experience perform three reps at their 6RM in a barbell bench press, a dumbbell bench press and a dumbbell fly. They recorded activity in the pectoralis major and anterior deltoid. Activation of both muscles was not significantly different across the three lifts. The dumbbell fly had a shorter relative time of activation than either press. The authors concluded that the dumbbell fly may suit an auxiliary role, while the barbell and dumbbell bench presses may be used interchangeably, and that alternating them may help lifters get past training plateaus.

Farias et al. (2017) studied 19 trained men. Each performed four sets at a 10RM load with a Smith machine, a barbell and dumbbells for the bench press, with two minutes of rest between sets. Each version was followed by a triceps extension. The main bench press findings were:

Two cautions apply. First, each load was a 10RM for that version, so the dumbbell and barbell loads were not matched; each person lifted whatever 10 reps to failure required in that version. Second, a higher EMG reading in one muscle does not show that the muscle will grow more. Farias et al. reported what happened across four sets in one session.

Taken together, the two studies suggest that the chest and front shoulder are working hard in both lifts, and that the arm muscles share the load a little differently. Whether those differences matter over months is unknown.

How do reps and load compare between dumbbells and a barbell?

At the same total weight, the two versions produce similar rep counts, with the barbell slightly ahead. That matters because many lifters assume dumbbells are far harder to press than a bar, and the data do not support a big gap for the athletes tested.

Heinecke et al. (2021) tested 40 college football players. They first found each player's one-rep max on the barbell bench press. On separate days the players then performed as many reps as they could with a 90.9 kg barbell and with dumbbells of the same combined weight. The results were:

• Barbell reps to fatigue averaged 13.8 (standard deviation 9.2), against 12.5 (9.5) for the dumbbells. The barbell was significantly higher, but the effect size was small at 0.14.
• The two rep counts were highly correlated (r = 0.96). A player who did well on one tended to do well on the other.
• Predicting barbell 1RM from reps to fatigue worked similarly well with each version: r = 0.90 with the barbell and r = 0.87 with dumbbells, with total errors of 7.3% and 8.2%.

The authors concluded that barbell and dumbbell repetitions at equivalent weights place a similar demand on the upper body for training and testing in football athletes. This was a group of 40 college football players doing sets to fatigue, so the results may not transfer neatly to a beginner or to low-rep sets. The lesson we draw, and it is our reading, is that if you have a known barbell number, you can estimate a sensible starting load for dumbbells by thinking in terms of total weight, then adjust by feel and effort.

Note how this sits beside Farias et al. In that study, dumbbells produced more total reps (31.2 against 27.8) at a 10RM load, while in Heinecke et al. the barbell produced slightly more reps at matched weight. The designs differ, so the studies do not contradict each other. They do show that "which version lets you do more reps" depends on how the comparison is set up.

Does it matter which one you train for strength?

Possibly, and the evidence for it comes from a related comparison rather than this exact one. A 2023 meta-analysis found that strength gains tend to be specific to the equipment you train on, and we found no direct long-term trial of dumbbell vs barbell bench press.

Haugen et al. (2023) pooled 13 studies and 1,016 participants comparing free weights with machines, not dumbbells with barbells. They found no difference between the two for hypertrophy (SMD -0.055) or for dynamic strength. They also found that strength increased more in the type of test that matched the training, and concluded that strength changes are specific to the training modality and that the choice comes down to individual preferences and goals.

Applying that to our question is an inference. It suggests, but does not show, that if your goal is a bigger barbell bench, you should expect barbell practice to carry over best, and that a dumbbell block may not transfer fully. If you compete in a barbell sport, that is a reason to keep the barbell as your main lift. Our paused vs touch-and-go bench press guide covers a related specificity question for powerlifters.

How should you choose between them?

Choose by the goal of the block, the equipment you have, and which lift you can progress steadily. The table below is our practical judgement built on the studies above, not a finding from them.

If you want a barbell number to start from, the bench press calculator estimates your max bench, and the plate calculator shows which plates go on each side of the bar.

How do you log dumbbell and barbell bench press in IronLedger?

Log them as two separate exercises and decide on one convention for dumbbell weight, per hand or combined. That keeps each lift's history comparable over time. IronLedger records weight, reps and RPE or RIR for every set, plus a note.

A practical set-up:

• Separate exercises: keep "Bench press" and "Dumbbell bench press" as different entries so a switch does not look like a drop or jump in strength.
• One weight convention: choose per hand or combined and write it in a note on the first set, for example "weight is per hand". We have not found an IronLedger setting that handles per-hand weight automatically, so the convention is yours to keep.
• Effort ratings: log RPE or RIR so a set of 8 reps at one weight can be compared to a set of 8 at another. Our RPE vs RIR guide explains how to rate sets.
• Trends: the progress view shows estimated 1RM and best set per lift across all logged sessions. Read estimated one-rep max before comparing a dumbbell estimate to a barbell one. Heinecke et al. found dumbbell reps predicted barbell 1RM with a slightly larger error (8.2% against 7.3%).

IronLedger does not tell you which version to use. It gives you a record to judge the swap against.

What mistakes should you avoid when comparing the two?

• Comparing per-hand weight with bar weight. A 40 kg dumbbell in each hand is 80 kg in total. Heinecke et al. matched total weight, so match it in your own comparisons, or compare by RPE or RIR instead.
• Reading EMG as a growth result. Higher activation in a muscle during one session does not show more growth in that muscle.
• Judging the swap in one session. A new lift feels different at first. Run a block of a few weeks before deciding.
• Treating a drop on the other lift as lost strength. The 2023 review found strength gains were specific to the equipment trained. A lower number after a switch fits that, though we cannot say how large the effect is for a given lifter.
• Using the fly as a main press. In Welsch et al., the dumbbell fly had a shorter relative time of activation than either press, and the authors suggested it as an auxiliary lift.
• Skipping depth or control to chase a heavier dumbbell. A heavier number with a shorter range is not progress. See full range of motion vs partial reps.

Keep learning

Related articles

Comparison

Paused vs Touch-and-Go Bench Press: Which Should You Train?

13 min read

Comparison

Incline vs Flat Bench Press: What the Research Says

13 min read

Comparison

Close-Grip vs Wide-Grip Bench Press: What the Research Says

13 min read