I've never been able to finish all ten events of a decathlon in track & field.
I don't even know what a decathlon is.
Well, you earn points based on how well you do in each event, and the events are things like shot put, pole vault, javelin throw, and various sprints.
Oh, so its similar to Olympic sports.
There is a decathlon at the Olympics, yes, but it can also be done at the collegiate level, non-professionally.
That's really cool. I didn't know people did it non-professionally.
All it takes is an enclosed grass field and an oval running track, really. Unless, of course, you can throw the javelin all the way out of the field...
I don't think I can, but I would love to see someone try.
You could always try the various foot racing events as well. You've got sprints, middle and long distance runs, and hurdling. 
Those sound like fun! Except for the hurdling. I'm not much on jumping.