Sure, shooting hoops in the backyard or a quick nine holes of golf is a nice bit of exercise on the weekend.

But some people require a little bit more of a challenge. Like climbing a skyscraper.

Or running a triathlon ... or three or four.

Maybe a car race that lasts an entire day ... or a month?

Whatever kind of insane physical and mental challenge you're looking for, one of these endurance challenges should fit the bill.

The Double Deca-Ironman Triathlon

Image: Wikimedia Commons

You've heard of an Ironman right? A 2.4-mile swim, followed by a 112-mile bike ride, followed by a full 26.2 mile marathon?

What if that wasn't enough? What if the only way to push yourself was to do it at twice the distance? Or three times? Or four? Or ten?

Or let's say you're completely insane. Then you should put your name in the hat for the Double Deca Ironman. A full Ironman Triathlon, every day, for 20 days in a row.

Then you die as the winner.

The Tour de France

Image: Wikimedia Commons

The supreme test of any cyclist, the epic, month-long race forces riders to scale some of the highest peaks in France, while dodging spectators, animals, cobblestones, and the occasional car.

The 2011 Tour had 21 stages and covered 2,132 miles and more than few ugly crashes.