A size-adjustable, foldable hamstring stretching apparatus of unitary construction provides for easily, effectively, and efficiently exercising (stretching) the hamstrings. The apparatus consists of a unitary frame and is used in a prone position, thus, avoiding back strain. The apparatus provides means for supporting the user's foot and means for assuring that the user's leg is maintained in a straight position. Means for holding allows for ease in grasping the apparatus allowing the user to pull or push the apparatus as desired. The means for supporting a foot, maintaining the leg in a straight position, and for holding may all be padded or made of a soft material for increased ease of use and comfort. The frame is made of any strong, lightweight material, such as plastic or aluminum and it is contemplated that the apparatus be made using a molding process to reduce the cost of manufacturing.