Account balances in 401(k) plans handled by the Principal Financial Group have gone up 93 percent, nearly doubling since the economic downturn in 2008, according to a survey by the Principal Financial Group.

Much of the increase reflects a rebounding market, but the study also found a significant increase in participation and savings rates since the market collapse, with account balances rising 17 percent in 2013 to an average of $54,000. Average account balances were at $27,400 in 2009 and $46,300 in 2012.

"The economic downturn may finally be in the rearview mirror, but the lessons learned from the crisis are hopefully influencing our savings habits as a nation moving forward," says Jerry Patterson, senior vice president of Retirement and Investor Services for Principal. "While we still have a lot of work to do to help Americans save at more adequate levels for retirement, these numbers are a positive sign that retirement savings are moving in the right direction."

In 2009, 14 percent of participants increased their contribution rate to their 401(k) plan. That number increased to more than 24 percent in 2013, the survey says. The average amount contributed also increased from 6.4 percent in 2009 to 7.3 percent last year.

The Principal Group recommends retirement plan sponsors have an automatic enrollment program with at least a 6 percent elective deferral rate and an automatic escalation of 1 percent a year up to 10 percent. The study included 1.8 million 401(k) participants.