Dumbbells

by Mark Rippetoe | April 09, 2024

I have a large collection of dumbbells in the gym. From 7 pounds to 128 pounds in relatively even jumps of about 5 pounds (the dumbbells are marked with their actual scale-measured weight, not the manufacturer's best intentions), the whole rack of 27 pairs represents a helluva lot of money spent a long time ago, back when I thought they were useful. They really aren't that useful.

Dumbbells are not stable in the hands in the same way a barbell is, since they are not connected by a solid bar if both hands are involved. They can move independently in all three axes, and stabilizing them is a supposed feature of their use. It's also a limiting factor in how much weight you can use in each hand, if you're pressing them either on a bench or overhead. In other words, you can't dumbbell bench or press with half in each hand of what you can bench or press with a bar.

But pressing movements are not the only exercises you can use dumbbells for. Dumbbell curls, dumbbell rows, dumbbell triceps kickbacks, dumbbell flyes, dumbbell snatches, and probably several other movements that do not constitute Strength Training can be performed by sufficiently clever trainees trying to avoid having to put 5 more pounds on their squat.

It's important to understand that the popular Alternate Dumbbell Presses do not make your press stronger, and dumbbell flyes don't make your bench go up. In the case of dumbbell presses, human force production against an external resistance is always at its maximum when exerted bi-laterally – both sides working at the same time in the same direction, like a deadlift. Unilateral force production is inherently inefficient since the entire body is not applying force against the resistance, and therefore not as much force can be applied.

And since the load is asymmetric, some of the muscle mass must be used to restore the symmetry and balance across the body as the load is moved. If you're pressing a dumbbell with your left hand, your right hand isn't loaded and your right-side leg and torso muscle is stabilizing your left side – with muscle mass that could be used to move the load if it was in both hands.

In the case of dumbbell flyes – no matter how they are performed – the pressing function is omitted and the shoulder joint musculature is all that is used. It is an intentionally inefficient exercise for your favorite muscle group, your pecs. Muscle not loaded is muscle not trained. More importantly, dumbbells are free to move in any direction, and the only thing that controls them is you. If the load is tied between your hands with a rigid bar, extraneous movement is minimized and more of the force can be used to drive the bar up. If the dumbbells can drift in any direction, some force that could be used to drive them up must instead be used to keep them from drifting, or hitting you in the head.

Strength is the ability to produce force against an external resistance. Both dumbbells and barbells are an external resistance. But since force is measured by the weight you lift, barbells have the potential to make you stronger, since you can lift heavier barbells than you can dumbbells over the same range of motion. As a general rule, if for some reason you want a heavier dumbbell bench press, get your barbell bench press up and the heavier dumbbells will follow. It doesn't work the other way around.

So much time and money have been wasted on dumbbell assistance exercises over the decades that it makes my heart break to think that I might have contributed to it. No novice lifter has any business doing anything with a dumbbell, or any isolation exercise machine. If you're an intermediate or advanced lifter and you want to do some “triceps” work – forgetting that your triceps get all the work they can actually perform from the pressing movements – go ahead, but don't get too carried away. I know you like doing them, and the muscle magazines have done their job so well that you cannot completely de-program.

But really, it's very simple: nobody ever put 100 pounds on their bench press with dumbbells, just like nobody ever put 100 pounds on their squat with knee extensions. Just ask them. If they're being honest, they'll tell you that no, my bench didn't go up because I did dumbbell benches – it went up because I put more weight on the bar and benched it.

However, I'm not getting rid of my dumbbell rack. It looks cool, and the north wall would be empty without it.