ATI Strength Shoes utilize plyometric construction to target calf muscle training: building mass and definition, while increasing quantity of fast twitch muscle fibers. Results include increase in vertical jump, reactive leg strength jumping skill, body coordination and range of motion. If you are a serious athlete or a parent of an athlete, the Katapult training shoe and scientific methodology when followed correctly, will give you or your child the tools to prepare for the next level of competition. The Katapult Training System and its scientific methodology is by far the most advanced plyometric workout available for the serious athlete. Athletic Training Innovations (ATI) working in conjunction with Karl Frank has created and patented its 52 week in-season off-season workout that will increase an athlete's vertical jump, speed, lower leg strength and flexibility while decreasing the risk of injury.