Opinions expressed by Entrepreneur contributors are their own. Tim S. Grover, known for his work with elite champions, wrote a book aptly titled Relentless, chronicling his training career and how he ...

Grover ( Jump Attack) spends half of his second book making a sales pitch for his sports-performance training services (at Attack Athletics in Chicago), and the other half lamenting the fact that most ...

This year, the inspiration is drawn from Tim Grover’s book “Relentless: From Good to Great to Unstoppable.” “Coach Nix and I will always read the book we use,” Jake Warwick, the assistant coach and ...