What is an adjustable dumbbell?

By the early 17th century, the familiar shape of the dumbbell, with two equal weights attached to a handle, had appeared. There are currently three main types of dumbbell:


Adjustable dumbbells which consist of a metal bar whose centre portion is often engraved with a crosshatch pattern (knurling) to improve grip. Weight disks (plates) are slid onto the outer portions of the adjustable dumbbell and secured with clips or collars. Alternatively, an adjustable dumbbell may have smooth ends with plates being secured by a sprung collar.

Fixed-weight dumbbells are weights created in a dumbbell shape and unlike adjustable dumbbells you can't change weight. Expensive varieties consist of cast iron, sometimes coated with rubber for safety. Cheaper versions consist of a rigid plastic shell that is filled with concrete.

"Selectorized" dumbbells are adjustable dumbbells whose weight is changed mechanically — for example, by turning a dial or moving a selector pin — rather than manually adding or removing plates. This makes it very easy to change the weight of the adjustable dumbbell between exercises. Such adjustable dumbbells often include stands that double as storage for the additional weights not being used for a particular exercise.