It's silly to argue over whether humans were "designed" to run that far. There are some things we definitely can't do, like jump fifty feet in the air or outrun

It's silly to argue over whether humans were "designed" to run that far. There are some things we definitely can't do, like jump fifty feet in the air or outrun a cheetah or stay underwater for two hours. But running a marathon is nowhere near the limits of human capability -- pretty much any able-bodied human being under the age of fifty can get there with sufficient training. I've never run a marathon but I've done a half and I'm planning a full one in the next few years. Of course the mental component is a lot easier for the happy-just-to-finish crowd like me than it is for anyone hoping to actually finish at the front.