Firms in the United States are targeting 4.9 percent growth in 2011, and a new study from Hay Group finds they're going to demand an increase in work force productivity to meet that goal.

The study, released Tuesday, reports global growth goals in most cases, outstrip International Monetary Fund (IMF) local economic forecasts for GDP growth. The U.S. growth target is well above the U.S. economic growth forecast of 2.8 percent reported in the latest figures released by the IMF.

“U.S. business leaders face a significant challenge as they work to achieve aggressive growth targets with a workforce that is already stretched thin,” said Katie Lemaire, vice president at Hay Group. “To fully harness the power of their employees, executives need to take a fresh look at how performance is really managed to ensure people are enabled to drive organizational performance.”