A hand-held gyroscope toy or gyroscopic muscle conditioning device with an outer shell containing a drive assembly with a spring-loaded drive button at one end that charges and discharges the gearing inside to provide an accelerated rate of rotation to a flywheel inside the outer shell. The resulting high-speed rotation causes a gyro effect that can be employed as either a fidget-type toy or a resistance device for fine motor or muscle development.

A posterior chain exercise apparatus, comprising: a frame; and a rotating weight assembly attached to the frame, comprising an adjustable back pad.