If you really love someone, and they love running, and you want to get them a really really good Christmas present, then probably go for one of those fancy new colour screen satellite watches that tell you when your bowels are full.
However if your budget is a bit more modest, or perhaps you don't love them that much or are not bothered by the present being brilliant then you could get them a book about running.
It's basically a tale about a normal bloke who does a few ultras and ends up running across the USA.
Hopefully the reviews on Amazon give you an idea of what the book is like.
I am also including two gift cards that I designed for runners. These retail at £2 each so £10 for the book and two cards is a bargain! Including postage too! Though only to the UK. I think EU is £5 and Rest of World is £8, but with the exchange rate that is cheap as frittes/fries.
Note this has nothing to do with having a garage full of books that my wife is getting annoyed about. Nothing whatsoever.
If you'd prefer the book on kindle then go ahead to amazon, it's only a fiver there.