Knowing that you have a deadline can make it easier to get things done. It doesn’t have to be necessarily professional— trying to get in shape by a vacation at the seaside, for example, can be a lot more motivating than a more vague and nebulous desire to get fit.

More scientifically, Maayan Katzir and colleagues at Tel Aviv University have investigated the phenomenon and they suggest it may be down to how we conserve and use effort. Our desire to engage in more interesting activities may have something to do with it. If we know that a tedious task is nearly finished, we also know that leisure activities are within our reach: remaining engaged in our task and taking fewer breaks means that those more appealing opportunities are closer to hand.

It may also be to do with how much effort we allocate to particular activities, the team suggests. If we have no idea how much longer we’re going to be engaging in a particular task, we’re unlikely to put all of our energy into it; if we know the end is near, we feel more able to try our hardest without fear of running out of energy.

The study was recently published in Cognition.