People work harder on their current task when they have a tougher task coming up.

Consumers will work harder on a task if they're expecting to have to do something difficult at a later time, according to a new study in the Journal of Consumer Research.

In today's fast-paced world, consumers frequently undertake unrelated tasks in a sequence. An individual might make a grocery list, decide whether to take out a home improvement loan, search the Internet for a vacation spot, and choose a dinner location—all before preparing lunch. "It seems reasonable to expect that when consumers know that they will have to work hard on a future task, they will devote less effort to the current task, in order to save energy for the upcoming demanding task. This is not what we found," write authors Anick Bosmans, Rik Pieters (both Tilburg University, The Netherlands), and Hans Baumgartner (Pennsylvania State University).

In a series of five studies, the authors observed that the more difficult a future task was expected to be, the harder consumers worked on a current task. "For example, consumers consulted more information on a web page when they were asked to evaluate a new soft drink when they expected that they would later on have to work on a difficult and demanding task," write the authors. Other participants were better able to come up with weight loss ideas when they believed they would have to work hard on a future job.

I've noticed this in my own performance. Faced with a difficult task I'm more efficient at getting through easier tasks even when I do not need to complete the easier tasks before doing the difficult one.

If you want to raise your overall performance then consider giving yourself more challenging tasks to do.