Apparatus for performing an arm curl exercise by a user comprising: a frame, a seat mounted on the frame in a position relative to the ground such that a user can sit on the seat with the user's feet touching the ground, a back rest mounted to the frame relative to the seat such that the user can engage the user's back against the back rest when seated on the seat, a pair of elbow pads mounted to the frame laterally relative to the back rest in an arrangement and adapted such that a user seated on the seat can engage the posterior surface of the user's elbows (13e, 13e) against the elbow pads when seated, an input arm assembly comprising a pair of two-link arms (30r, 30f) having a fixed pivot point on the frame and a dual axis pivot (30fb, 30fa, 30rb, 30ra) at an elbow, the two-link arms being pivotable about a first linear axis at the fixed pivot point, the two-link arms comprising first and second arm portions (30r, 30f) joined at the elbow and the dual axis pivot comprising a second linear axis generally parallel to the first linear axis and a third linear axis generally perpendicular to the first linear axis, wherein the second arm portion is pivotable around both the second linear axis and third linear axis at the dual axis pivot (30fb, 30fa, 30rb, 30ra), the two-link arms being connected to a manually selectively adjustable weight resistance mechanism at a distal end of the two-link arms, and a pair of manually graspable grips or handles rotatably mounted at the distal end of the two-link arms, the two-link arms being mounted and adapted to dispose the grips or handles in a starting or rest position forwardly and below the point of engagement of the user's elbows with the elbow pads. a frame, a seat mounted on the frame in a position relative to the ground such that a user can sit on the seat with the user's feet touching the ground, a back rest mounted to the frame relative to the seat such that the user can engage the user's back against the back rest when seated on the seat, a pair of elbow pads mounted to the frame laterally relative to the back rest in an arrangement and adapted such that a user seated on the seat can engage the posterior surface of the user's elbows (13e, 13e) against the elbow pads when seated, an input arm assembly comprising a pair of two-link arms (30r, 30f) having a fixed pivot point on the frame and a dual axis pivot (30fb, 30fa, 30rb, 30ra) at an elbow, the two-link arms being pivotable about a first linear axis at the fixed pivot point, the two-link arms comprising first and second arm portions (30r, 30f) joined at the elbow and the dual axis pivot comprising a second linear axis generally parallel to the first linear axis and a third linear axis generally perpendicular to the first linear axis, wherein the second arm portion is pivotable around both the second linear axis and third linear axis at the dual axis pivot (30fb, 30fa, 30rb, 30ra), the two-link arms being connected to a manually selectively adjustable weight resistance mechanism at a distal end of the two-link arms, and a pair of manually graspable grips or handles rotatably mounted at the distal end of the two-link arms, the two-link arms being mounted and adapted to dispose the grips or handles in a starting or rest position forwardly and below the point of engagement of the user's elbows with the elbow pads.