A barbell includes a bar, a first sleeve assembly having a first sleeve with a first proximal bore portion, a first distal bore portion, and a first central bore portion extending therebetween. An inner proximal bushing is received in the first proximal bore portion, a proximal bearing received in the first proximal bore portion and having two sets of roller bodies positioned between inner and outer races. An outer proximal bushing is received in the first proximal bore portion. The outer proximal bushing engages the first sleeve and the outer race. The outer surface of the inner race has a first annular channel receiving the first set of roller bodies and a second annular channel receiving the second set of roller bodies, and the inner surface of the outer race has a concavely curved annular channel receiving both sets of roller bodies.

A dumbbell having a shaft, first and second dumbbell heads, respectively fixedly connected to first and second ends of the shaft, a tube-shaped hollow grip rotatably arranged around the shaft having first and second ends. An inner diameter of the grip is greater than an outer cross-sectional dimension of the shaft. The dumbbell further having a first ball bearing and a second ball bearing, wherein an outer ring of the first ball bearing is connected to the first dumbbell head, and an inner ring of the first ball bearing is fixedly arranged to the first end of the hollow grip, and an outer ring of the second ball bearing is connected to the second dumbbell head, and an inner ring of the second ball bearing is fixedly arranged to the second end of the hollow grip.

A weight training apparatus, includes a central body comprising a width and a depth, wherein the width of the central body is greater than the depth. The weight training apparatus further includes a first handle comprising an opening coupled to the central body at a first position and a second position on a top surface of the central body, wherein the first handle is positioned laterally relative to the width of the central body, a second handle coupled to the central body at a third position on a first side surface of the central body, and a third handle coupled to the central body at a fourth position on a second side surface of the central body, wherein the second side surface is adjacent to the first side surface.

A weight plate that is comprised of multiple parts that connect to each other around the handle of a progressive resistive device.

A dumbbell may include a handle, a first weighted portion and a second weighted portion, wherein the first weighted portion and the second weighted portion are located at two opposite ends of the handle. In one embodiment, the first weighted portion has a cover and a receiving space, and the receiving space has a center receiving hole and a plurality of surrounding receiving holes, each of which is configured to receive an elongated center weighted unit and one or more surrounding weighted units. Likewise, the second weighted portion has a cover and a receiving space having a center receiving hole and a plurality of surrounding receiving holes that can be used to receive each of the center and surrounding elongated weighted units. In one embodiment, the cover can be threadedly engaged with the outer peripheries of the first and second weighted portions.

An adjustable dumbbell device includes one or more weight members and one or more weight elements each having two side panels to form a chamber, and an opening formed in each of the panels, two housings detachably engaged in the weight member and the weight element, two catches slidably engaged in each of the housings and engageable with the openings of the panels for anchoring the housings to the weight member and the weight element selectively, two followers are rotatably engaged in each of the housings and each include a gear engaged with the catches for moving the catches to engage with the panels and to anchor the housings to the weight member and the weight element respectively.

An adjustable dumbbell system may include a handle assembly, at least one weight, at least one sensor, and a computing device. The at least one weight may be selectively fixedly connectable to the handle assembly. The least one sensor may be positioned on the handle assembly. The at least one sensor may be configured to detect a handle assembly attribute indicative of whether the at least one weight is fixedly connected to the handle assembly. The computing device may be in communication with the at least one sensor and may be configured to receive information regarding the handle assembly attribute from the at least one sensor.

An adjustable dumbbell includes a base, a grip, and a plurality of sets of dumbbell plate assemblies connected on both sides of the grip. The dumbbell plate assembly includes a rotating member, an adapter, a limiting member and a weight plate. The rotating member rotates with the grip. The limiting member is located between the rotating member and the adapter. The limiting member fits with and is connected to the adapter in a non-rotatable manner. When the rotating member rotates, the rotating member abuts against the abutting rib to drive the limiting member to translate, so that the protrusion is inserted into or separated from the insertion hole to connect or separate the limiting member and the adapter.

An adjustable weight training apparatus. The adjustable weight training apparatus has a vessel with a plurality of compartments, the plurality of compartments having a compartment size and a compartment shape. A plurality of weights has a weight shape the same as the compartment shape and a weight size slightly smaller than the compartment shape such that any individual weight of the plurality of weights fits within any individual compartments within the plurality of compartments. The adjustable weight training apparatus further has a retaining lid, wherein the retaining lid is manually attachable and removable from the vessel, the retaining lid securing any of the plurality of weights loaded within the vessel. Adjustment of an overall weight of the adjustable weight training apparatus requires manual loading and there are no adjustment mechanisms, no weight selectors, no weight switches, and no other means of automatically adjusting the overall weight of the adjustable weight training apparatus.

A weight attachment mechanism for a barbell; the attachment mechanism may include: a base including a receiving end and a mounting end; a fixed arm; an opening arm; and a sheath having an inner surface and an outer surface. The fixed arm and the opening arm may be configured to be mounted to the mounting end of the base. The opening arm may be movable relative to the fixed arm in order to receive a weight between the fixed arm and the opening arm. The inner surface of the sheath may be configured to fittingly engage at least a portion of the base. The receiving end of the base may be configured to attach to an end of the barbell.