> Now, if they're is a ball to chase and a game to win, I can run until I fall over... Well, there's the solution :) Make a game out of it. Some find it helpfu

> Now, if they're is a ball to chase and a game to win, I can run until I fall over... Well, there's the solution :) Make a game out of it. Some find it helpful to reward themselves if they can reach some sort of goal (under X minutes per km) and not otherwise, then you have something of a game. Otherwise, if you're a bit competitive, find another competitive friend and compete who can run for longest without giving up. Loser buys the other one beers for evening.