Adjustable dumbbell

An adjustable dumbbell, comprising a dumbbell bar, linear adjusting mechanisms and counterweight mechanisms, wherein the linear adjusting mechanisms and the counterweight mechanisms are disposed at both ends of the dumbbell bar, said dumbbell bar includes a sleeve and two telescopic mandrels disposed in the sleeve and in sliding fit with each other;

• said counterweight mechanisms are coaxially disposed at the both ends of the dumbbell bar, and configured to provide an overall weight of the adjustable dumbbell;
• and
• each of said linear adjusting mechanisms comprises a limiting assembly and a gear adjusting assembly, wherein
• the gear adjusting assembly is configured to allow the two telescopic mandrels to be close to or away from each other, so as to control an overall combination length of the two telescopic mandrels;
• and the limiting assembly is configured to limit the gear adjusting assembly.