PositiveThe Boston GlobeBy examining how far scientists have come in understanding the impact of genes on athletic performance and what remains undiscovered, Epstein adds another layer to the ongoing debate ... But beyond that, Epstein’s first book offers a different prism for viewing athletic performances or, at least, a welcome departure from now-popular number crunching. In a sports world increasingly worshipful of analytics, The Sports Gene provides a refreshing reminder of the many variables that impact and predict success. By discussing the way athletic physiques have become more specialized, the way genes affect muscle development, and the way some ultrarunners crave activity, Epstein may change how fans view their favorite players and challenge assumptions about athleticism ... even though some sections are filled with technical talk, he makes the science behind the studies easy to digest and accessible to both avid and casual sports fans ... The Sports Gene is most engaging when sections combine science with real-life examples and when anecdotes and athletes move away from popular American professional sports.