Try this for a day: don't answer every phone call. Stop checking your email every two minutes. And leave work early. You'll be astounded at how much more you'll get done.

According to a study published in the Psychological Review conducted by Dr. K. Anders Ericcson, the key to great success is working harder in short bursts of time. Then give yourself a break before getting back to work.

The trick is staying focused. Ericsson and his team evaluated a group of musicians to find out what the "excellent" players were doing differently. They found that violinists who practiced more deliberately, say for 4 hours, accomplished more than others who slaved away for 7 hours. The best performers set goals for their practice sessions and required themselves to take breaks.

Looking at the chart, you can see that the best violin students practiced with greater intensity just before the lunch hour and then took a break before starting up again at 4 p.m. -- whereas the other students practiced more steadily throughout the entire day.

The researchers found that successful people in other professions had similar habits:

"While completing a novel, famous authors tend to write only for 4 hours during the morning, leaving the rest of the day for rest and recuperation. Hence successful authors, who can control their work habits and are motivated to optimize their productivity, limit their most important intellectual activity to a fixed daily amount when working on projects requiring long periods of time to complete."

Timothy Ferriss gives similar advice in his New York Times bestseller, The 4-Hour Workweek. He stresses the Pareto principle, or the 80/20 law, which is that 80 percent of outputs come from 20 percent of inputs. So stay focused, and you'll do more in less time.

For more productivity tips check out 9 Ways to Work Less and Do More >