"Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance" by Alex Hutchinson 4/5
Alex Hutchinson is an athlete and recognised author. His scientific approach makes the content serious and precise but at the same time enjoyable to read, thanks to having individual stories and being backed by tons of research. Each chapter corresponds to a limiting factor of our physical capabilities. They’re intertwined with a record-breaking event of running a marathon under 2 hours.
It does not contain breaking revelations but summarises what we know about endurance and points out what is still unknown. It's interesting to acknowledge all the factors, so I recommend it to anyone interested in any aspect of the physical and mental capabilities we all have, not necessarily just athletes looking for a winning edge.