Abstract: A leg exercise device for permitting isolated exercises of selected muscle groups of the lower extremity comprising a generally tubular ankle collar or boot having an inner surface conformingly fitted to a user's ankle region. The outer forward facing surface of the ankle boot includes an upturned J-shaped hook member adapted to receive a weight clip member. The weight clip member includes means for retainingly engaging a rod or bar portion of a conventional weight, such as a dumbbell, and is lockable to the hook member of the boot. The boot includes front and back half portions which are hinged together along a first common side and which have an adjustable buckle member for closing the two halves together along their second common side. The front half portion of the boot includes a anti-torsion strap member which is looped under the ball of the user's foot to prevent up and down and side-to-side or torsional movement during use.