RIPPING AT THE SEAMS By Melissa Frankel, Jayplay writer After an intense practice, 10-year-old Matt Reaves can't imagine moving his legs, let alone lift them. He and his teammates are sprawled out on the ground, willing their tired muscles to budge. That's when Reaves notices his dad, who coaches his fourth grade football team in Derby. Bob Reaves is known as "the big guy." With one glance at his bulging muscles, you know why. Coach Reaves calls the team over to him. He lies on the ground, lifts up one leg and tells the team to walk across his stomach, cleats and all. At that moment Matt Reaves decides that when he grows up he wants to be big and strong like his dad. Reaves is now a sophomore at the University of Kansas. When you see his 6-foot-1-inch, 250-pound physique, it's clear he is striving to achieve his childhood goal. With his 18 and a half inch-wide arms he can bench 450 pounds. Reaves says he always knew he wanted to look like his dad, but when he picked up the magazine Muscle and Fitness five years ago, he became hooked on bodybuilding. He carried the magazine with him everywhere and decided to start lifting weights regularly. Reaves says bodybuilders are trying to build the perfect person. That requires a huge commitment; self discipline, hours spent following a strict workout routine and, ideally, devotion to a healthy diet. Bodybuilders inspire awe and sometimes revulsion, but people might be surprised to know what bodybuilders think when they look in the mirror. Even well-formed muscles can seem small to a bodybuilder's critical eye. Bodybuilding increases muscle volume. Lifting weights puts stress on muscles by forcing them to move more weight than they are used to. As muscles heal from the strain, their muscle fiber size increases. Bodybuilding also improves a person's metabolism and ability to maintain physical strength. Scott Richmond, a St. Louis, Mo., graduate student who conducts research in