Across the world seemingly ordinary people are undertaking extraordinary challenges that will push their limits to achieve the improbable - by sea, bike, foot or sled. From the Badwater Ultramarathon in the unforgiving heat of Death Valley in California to the freezing wilderness of Alaska, these once-in-a-lifetime experiences are increasingly popular, and strangely addictive. For a certain breed of competitor, there is an unbreakable drive to see exactly how much the body and will can endure. Ultra-endurance events in the hottest, coldest, highest, most remote locations - these are no Sunday morning excursions but gruelling fights for survival and victory. This book looks at 50 of the most extreme marathons, triathlons, bike rides and other iconic endurance events from around the globe. The World"s Toughest Endurance Challenges is a truly inspiring and beautiful collection of what we can achieve when racing to the limits. With full-colour stunning photography, coverage of every detail of these cruel challenges and including accounts of competitors who have lived to tell the tale, this book is a wonderful testament to those who face Mother Nature and survive.