If you want coaching from a running book, look for one that provides reasonable, effective, and—above all—sustainable training methods. Make sure the training is evidence-based and that the author is a professional with credentials to back up their advice. Author credentials to look for include personal training certifications from the National Academy of Sports Medicine (NASM) or the American Council on Exercise (ACE) and a running certification from the Road Runners Club of America (RRCA).