While investment professionals view market risk as their big enemy, U.S. workers have a more fundamental fear: going broke in retirement.

Those were among the findings in a survey by American Century Investments that revealed that, in some key areas, there is a divergence in views between defined-contribution plan sponsors and workers.

"We found that plan sponsors and participants are on the same page regarding debt being the primary barrier to saving," Diane Gallagher, a company vice president for client marketing, said in a prepared statement. "However, their views on risk, preferred levels of involvement by employers and the importance of environmental, social and governance (ESG) offerings clearly varied."

Risk perception was a big area where the two groups differed, with 40% of retirement plan sponsors saying market risk is the most important factor in target-date investments and 41% of workers citing the danger of running out of money in retirement.

The report included survey responses from 500 defined contribution plan decision makers and 1,500 full-time workers between the ages of 25 and 65, according to American Century.

Another area where views differed was in the level of retirement help that employers should provide their employers. The survey found that while 80% of workers wanted at least a "slight nudge" in the right direction from their employers, plans sponsors think about 28% of workers just want to be "left alone."

"Employers underestimate the level of help employees want," Gallagher said. "We tend to listen to the 'squeaky wheel,' the person who says, 'I've got this,' but most workers want help; they want guardrails."

In the area of ESG investments, 90% of sponsors offering or considering offering such investments said they believe their employees are interested in them, but only 37% of employees surveyed expressed such interest.

"It will be interesting to track employee sentiment in the future and compare their interest in ESG choices down the road as individuals become more familiar with the term," she added.

Sponsors and workers, however, were in agreement that debt is the primary barrier to saving for retirement. It's the first time in the seven years of doing the survey that debt was the most-cited barrier, over factors such as not earning enough, unexpected expenses and enjoying today rather than saving, according to American Century

"We've heard plan participants say that they were always trying to get out of debt, so they didn't start saving early enough," Gallagher said. "The most important thing workers can do is take advantage of their retirement savings plan at work."