The optimism that consumers felt heading into this year was short-lived, and has been overcome by nagging concerns over their debt loads.

The economy is recovering its footing, thanks to consumers who provided it with a shoulder to lean on by taking advantage of exceptionally low interest rates to buy homes and other big-ticket items.

But the tables are set to turn. Policy makers are hoping that new strength in the economy will give consumers the support they need to straighten out their finances, even as interest rates inevitably begin to rise.

It's an untested hypothesis. This is the first recession in which real credit, the amount of debt that people are taking on adjusted for inflation, has risen.

And growing anxiety about paying down debt suggests that the central bank's ability to fuel the economy with ultra-low rates could lose steam if consumers retract from their borrowing binge.

New figures that were released by the Bank of Canada on Friday show that the amount of consumer credit held by the country's chartered banks rose to $335.6-billion in December, up from $333.6-billion in November and from $291.7-billion in December of 2008.

The turn of a new year, coupled with a greater belief that interest rates will rise in the next six months, appears to have prompted more contemplation about debt levels.

And, as they evaluate their household finances, the majority of Canadians are worried.

Fifty-eight per cent of consumers are concerned about their debt loads, according to the January RBC Canadian consumer outlook index, which comes out today. It's the first time that that question has been added to the survey, but it's a fairly safe assumption that concern has risen.

“Canadians are clearly worried about their current level of debt,” said David McKay, the head of Canadian banking at Royal Bank of Canada.

“We know that the anxiety about a couple of other things has gone up,” added Marcia Moffat, who runs Royal Bank's mortgage business. “We saw people delaying major purchases, so they did some belt tightening. They're a little less positive about the Canadian economic outlook, and they're more concerned about jobs.”

Sixty-eight per cent of Canadians expect interest rates to rise in the next six months, up from 57 per cent in the prior month.

Higher rates will mean higher monthly payments on many debts, an inevitability that is spurring concern.

“We've been squeezing the consumer pretty hard as a means of offsetting the decline in external demand,” said Stewart Hall, an economist at HSBC Securities. While U.S. consumers are de-leveraging, Canadians continue to rack up debt. “We've ridden through this recession largely on the back of domestic consumer demand,” Mr. Hall noted.

To transition on to a sustainable economic growth path, demand from the private sector must bounce back, along with exports. “We need to see the consumer hand off some of the responsibility for growth,” Mr. Hall said.

With a little luck, the recovery will help boost disposable incomes, allowing debt-to-income levels, which are currently at an all-time high, to recover.

But some consumers are tapped out and won't be able to cope with rising rates. “Consumer bankruptcies have risen significantly over the past year, and they will continue to rise,” said Canadian Imperial Bank of Commerce chief economist Benjamin Tal. “Clearly, some people are in over their heads, and more will get into trouble when interest rates rise.”

The problem does not threaten to derail the recovery, but it will pose challenges, he suggested.

“We are stealing or borrowing activity from the future,” Mr. Tal said, especially in the housing market where many consumers have felt that if they didn't act now they'd miss the boat. “It means that borrowing and real estate activity will not be as strong in 2011, and that's the price we pay for today's activity.”

In evaluating the extent of the problem, Mr. Tal believes there has been too much focus on ballooning debt-to-income ratios, and too little focus on debt-to-asset ratios, which have remained relatively steady.

In fact, assets have been rising faster than liabilities since the second quarter of 2009, meaning that the net worth of individuals' is on the upswing. However, that's largely a result of surprising increases in stock markets and home prices, which gave consumer balance sheets a lift.