Eh, so what? Running a marathon in 3 hours is hardly the sort of heroics that D&D characters have problems with. Weak D&D characters can jump off 3 storey houses and be just fine after a 5 minute breather.This makes about as much sense as extrapolating a lightly loaded character's combat running speed (8 squares per move action) to miles per hour (about 9.1) and concluding that pretty much any D&D character can run a marathon in under three hours.
Which is to say, it doesn't make sense. In real life, running a 3-hour marathon requires significant training. It might be perfectly reasonable to represent this in D&D as training in Endurance.
Once again for those who don't want to shell out for DDI?Similarly, the ability to use Mage Hand to dig out tons of earth over the course of an hour shouldn't be a given; it might be represented by some kind of special study or training... perhaps some sort of arcane incantation that the character could learn...![]()
Once again for those who don't want to shell out for DDI?
The same thing that someone already stated above; the Excavation ritual.
That said: I've yet to be in a game where the number of tonnes of dirt my party can move per hour has proven to be in any way interesting.
That said: I've yet to be in a game where the number of tonnes of dirt my party can move per hour has proven to be in any way interesting.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.