Not to be mistaken for a football epic, this comeback story about world-class distance runner Steve Heidenreich has its puzzling and frustrating side. ""Heidi"" (referred to throughout in the third person) was only months away from the 1976 Olympic trials when a hit-and-run driver left him so brain-damaged that his surgeon predicted for him the life (if he lived) of a vegetable. Heidi emerged from the coma barely able to walk, verbally crippled by aphasia, and with the emotional stability of a two-year-old. Now comes the frustrating part: Heidi's passionate, singleminded dedication to ""running back""--returning against all odds to Olympic-level competition--is portrayed more as a loner's obsession than as a champion's courage. Careful cataloging of even relatively minor meets throughout his career contributes to the impression of compulsive behavior. Then, too, the narrative is disjointed--people are displayed as conglomerations of qualities, and there are digressions to such topics as the lack of Olympic training facilities: in short, the seams show. The ending is yet to be written; Heidi is hoping to make the 1980 Olympics (he's now 26), and, if that fails, there's always 1984. For sheer effort and persistence, one hopes he'll make it; but if he doesn't, this book will do little to immortalize him.