Senior-level men also say they are 12 times more likely to be hesitant about one-on-one meetings with a junior woman than they are a junior man, nine times more likely to be hesitant to travel with a junior woman for work than a junior man, and six times more likely to be hesitant to have a work dinner with a junior woman than a junior man.

According to the survey, released by LeanIn.org and SurveyMonkey, that's a 33% increase from last year.

The #MeToo and Time's Up movements have brought huge attention to the challenges women face at work, but a new survey finds that 60% of male managers say they're uncomfortable participating in regular work activities with women, including mentoring, working one-on-one or socializing.

LeanIn.org founder and Facebook COO Sheryl Sandberg calls the results "totally unacceptable."

She tells Julia Boorstin on CNBC's "Squawk on the Street" that the problem with this dynamic is that "women already weren't getting the same mentorship men were, particularly women of color." And in her experience, she says, "no one has ever gotten a promotion without getting a one-on-one meeting."

Though some have argued that the #MeToo and Time's Up movements have had a negative impact on relationships between men and women at work, Sandberg disagrees. She says the movements have had an "overwhelmingly positive" impact on the workplace, especially in spotlighting the problem of sexual harassment against women.

"The thing is, it's not enough," she says. "It's really important to not harass anyone, but that's pretty basic. We also need to not be ignored."

Rachel Thomas, president of LeanIn.org, tells CNBC Make It that "sexual harassment is a lot of things, and it's a really complicated issue, but a big piece of it is power dynamics."

"We need more women in positions of leadership, more people of color and more LGBTQ people," she says. "We need to change what leadership looks like in our organizations because we know that will lead to more safer and stronger workplaces."

Both she and Sandberg point out that sexual harassment is twice as likely to occur in organizations where men dominate the C-suite. That's why, Thomas says, it's imperative that men speak up and take action. "My suspicion is that a lot of good guys don't realize that by not actively mentoring, sponsoring or creating full access, that they're inadvertently part of the problem," Thomas says.

As a solution, Thomas and Sandberg say any man who doesn't want to have work dinners with a woman should also not have work dinners with a man. Instead, they should have group dinners so that everyone is included.

"That's one way to create equal access," says Thomas. "I don't fully understand it, but for whatever reason if a man is also uncomfortable having a one-on-one meeting with a woman or working with a woman, then leave the door open."

Regardless of how a man may feel about working with a woman, Thomas says there is "no excuse for not being a good manager, not being a good leader and not offering equal access to the mentorship and sponsorship that we know all employees need to succeed."

Correction: This story was revised to correct a headline. The researchers found that 60% of male managers now say they're uncomfortable participating in work activities with women.

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