In 1988, bicycle enthusiast Michael Eidson took part in a 100km bike race in the scorching summer heat of Texas. Water was essential to survive the race and there were too few places to refill a water bottle. Eidson, an emergency medical technician, decided to fill an IV bag with water and stash it in a white tube sock. Then he stuffed his invention into the back of his bike jersey, threw the thin hose over his shoulder and secured it in places with a clothes pin. This DIY contraption allowed him to hydrate hands-free whilst he pedalled. And while it may have got a few odd looks from his fellow racers back then, today it's hard to imagine sports nutrition without the hydration backpack. Despite its many imitators, the original still impresses today.