I originally bought this book and read it 30 years ago in college - over and over again. I was never a jock and although active in a number of sports I did not have high regard for my abilities (even though I was quite good at some sports, like fencing). I did distance running for health but flat feet prevented me from being fast. I considered myself a second-string bench warmer until I read this book. It completely changed my vision of what being an athlete was about and it spurred me on to continually strive to push myself outside my envelope and constantly demand excellence from myself - not measured against the impossible yardstick of others but rather against the measure of three feet past the wall of my own self-limitations.
While in no way a religious book, an undercurrent which flowed throughout the entire book dealt with the spirituality of physical endeavor. While the book is about physical activity it's principles apply not just to running or high-jumping or team sports but to playing Frisbee and fasting and studying and working and raising children and doing ANYTHING that requires endurance and dedication and grit and pain-tolerance and pushing beyond my own self-imposed limitations to reach a higher goal than mere mediocrity.
I again purchased this book not just for myself but for my children as well, that they might strive for excellence and become the Ultimate Athlete they have the potential to be.