GALVESTON, Tex., April 21 — On the edge of the Texas Gulf is a 370-pound football player who can execute a perfect forward flip.

When he lands, the ground trembles.

Big Walt, as he is known, is a 6-foot-5 defensive tackle who wears a size XXXXXXL jersey. He bench presses 475 pounds and squats 800 pounds. Weight lifters at the Galveston Health and Racquet Club stop their workouts to watch him.