Mike Stroud, polar explorer, practising hospital physician and until recently adviser to the Ministry of Defence on matters of survival, sets out in this fascinating book the genetics, diet and exercise that are employed to enable human beings to perform at their peak. Based soundly in medical science, the book takes an anecdotal form, describing individual feats of survival and athletic prowess that illustrate the way the body functions at its best. In a highly entertaining and humourous way, Dr Stroud dissects his own experiences crossing Antarctia (the subject of his bestselling book Shadows on the Wasteland), running marathons in the Sahara and participating in gruelling cross-country endurance races in the United States. He charts the astonishing bursts of speed produced on the running track by Linford Christie, the stamina and concentration of tennis star Martina Navratilova, and some remarkable mountaineering fears and military escapes. He ends with some hints for those of us who do nothing more strenuous than walking the dog on how we too may remain 'fit for life'.