A training device properly develops a sports equipment swing, particularly for golf equipment, to counter an overpowered back-swing that results in an uncontrolled out-of-plane downswing. The device may comprise a strap having one end secured to a latch plate, and the other end securable to a latch that releasably receives a portion of the latch plate. At least one bungee cord may have one end attached to the strap at a position relative to the latch, being approximately 4-12 inches displaced therefrom. The other bungee cord end may have a cinching device located thereon to adjustably secure the bungee cord therein to engage a golf club shaft or shaft of a sports racquet, bat or stick. The bungee cord may comprise first and second cord portions being joined together, where the first cord portion has a low elastic modulus, and the second cord portion a high elastic modulus.