Just forty years ago, Jim Hines ran the 100 metres in under 10 seconds. Now Usain Bolt is inching close to the 9.50 second mark, begging the question: exactly how fast can a human go? Utilizing cutting edge science to examine incredible physical feats in the most elite sports, John Brenkus uncovers what it takes to reach the 'perfection point' of the marathon - that measurement of speed that supreme athletes can inch closer to but never exceed. Shining a light on the crucial balance between physical stamina and emotional drive, this is the ultimate guide to the further limits of human performance. 'Lively and engaging...this stuff is catnip to sports fans' Wall Street Journal