The prospect of a recession has more middle-aged Americans worried about their retirement savings, though few are taking steps to change their financial plans, a recent survey found.

In a Harris Interactive poll sponsored by Longevity Alliance, a Washington, D.C.-based financial planning firm, more than half of 831 respondents said they have grown more worried about their retirement savings since the end of last year.

Despite growing concerns, only 39 percent said the risk of a recession had prompted them to change their retirement savings plans. Of those that had made changes, only 43 percent said they planned to seek a financial advisor.

"Baby boomers know the train is coming, but they're frozen on the tracks," Longevity Alliance President Steve Zaleznick said in a statement. "Unfortunately, too many are unsure of the best steps to take to guarantee that their money lasts through retirement."