A selectorized dumbbell, which comprises: (a) a plurality of nested exercise weights in which each weight comprises a left weight plate (6 l) and a right weight plate (6 r) which are spaced apart from one another but which are joined to one another to form a single weight by at least one interconnecting member extending between and being attached to the weight plates (6 l, 6 r), the weight plates (6 l, 6 r)and the at least one interconnecting member of each weight being separate and distinct from the weight plates (6 l, 6 r) and the at least one interconnecting member of the other weights; (b) a handle; (c) a selector that is selectively adjustable on the handle to couple different numbers of exercise weights to the handle to vary the exercise mass provided by the dumbbell; and (d) wherein each weight has a releasable connection between each of the left and right weight plates (6 l, 6 r) and opposite ends of the at least one interconnecting member for attaching the left and right weight plates (6 l, 6 r) to the at least one interconnecting member, wherein each connection comprises: (i) an opening formed in the each of the left and right weight plates (6 l, 6 r), the opening comprising at least first and second contiguous and interconnected portions (46, 48); and (ii) characterized in that each end of the at least one interconnecting member is shaped to be capable of being freely inserted into the first portion of the opening in a first insertion direction and to be then subsequently moved within the second portion of the opening in a second securement direction that is different than the first direction to secure the at least one interconnecting member and the left and right weight plates (6 l, 6 r) together. (a) a plurality of nested exercise weights in which each weight comprises a left weight plate (6 l) and a right weight plate (6 r) which are spaced apart from one another but which are joined to one another to form a single weight by at least one interconnecting member extending between and being attached to the weight plates (6 l, 6 r), the weight plates (6 l, 6 r)and the at least one interconnecting member of each weight being separate and distinct from the weight plates (6 l, 6 r) and the at least one interconnecting member of the other weights; (b) a handle; (c) a selector that is selectively adjustable on the handle to couple different numbers of exercise weights to the handle to vary the exercise mass provided by the dumbbell; and (d) wherein each weight has a releasable connection between each of the left and right weight plates (6 l, 6 r) and opposite ends of the at least one interconnecting member for attaching the left and right weight plates (6 l, 6 r) to the at least one interconnecting member, wherein each connection comprises: (i) an opening formed in the each of the left and right weight plates (6 l, 6 r), the opening comprising at least first and second contiguous and interconnected portions (46, 48); and (ii) characterized in that each end of the at least one interconnecting member is shaped to be capable of being freely inserted into the first portion of the opening in a first insertion direction and to be then subsequently moved within the second portion of the opening in a second securement direction that is different than the first direction to secure the at least one interconnecting member and the left and right weight plates (6 l, 6 r) together. (i) an opening formed in the each of the left and right weight plates (6 l, 6 r), the opening comprising at least first and second contiguous and interconnected portions (46, 48); and (ii) characterized in that each end of the at least one interconnecting member is shaped to be capable of being freely inserted into the first portion of the opening in a first insertion direction and to be then subsequently moved within the second portion of the opening in a second securement direction that is different than the first direction to secure the at least one interconnecting member and the left and right weight plates (6 l, 6 r) together.