Kathy is downstairs, exercising while waiting for Miguel to return.

Miguel is with Judy Clarke, who discusses the design of athletic shoes. She leads Miguel to two other researchers, ready to do measurements on Miguel's feet. Miguel weighs 135 pounds, and the impact each foot endures while he runs is twice that weight. In between the experiments and observations, Judy tells Miguel what type of athletic shoe would be best for running.

Back at the basement, Kathy sprains her knee.

Robin sees Sammy Duvall, a world-champion water skier. He talks about the stress a water skier meets during a jump. They meet Dr. Michael Fulton, who shows Robin the forces a knee faces when walking, jogging, and jumping. Fulton explains what kind of injury Sammy had in 1979 and how the doctors countered the injury. Sammy gives Robin a water-skiing lesson.

Paco walks to the basement wearing street-hockey pads, all of which impress Kathy.

Robin is at a softball game, quickly learning that she must wear a