Simon Donato

After five days and almost 250 kilometres of running through the shifting sands and hair-dryer heat of the Sahara Desert, Simon Donato had reached the limits of his physical endurance. The 37-year-old from Canmore, Alta., who travels the world competing in the most gruelling ultra-endurance races as co-host of the TV adventure series Boundless, knew he had to cover another 30 km to reach the finish line, but he could barely put one foot in front of the other.

Calgary-based adventurer and ultra-marathoner Simon Donato has just returned from a series of eight endurance races around the world - he joins us to talk ...

For Boundless, Simon Donato and Paul "Turbo" Trebilcock are doing the unthinkable: tackling eight of the world's toughest endurance races in a row. So what ...