I find that my short term goals or benchmarks keep me accoutable by always having something that I am working towards. If I was just running or lifting and not trying to achieve a new
PR or faster race time my training would be less focused. The same with my diet. I know that my diet is directly connected to my achievement of my fitness and performance goals. If I wander off on an unplanned lost weekend of beers and pizza it is going to adversly affect my training and therefore keep me from attaining my goals.