Bad news if you think collaboration is the secret to boosting creativity and productivity at your company: The surge in collaboration is not only eating up your employees' time, but up to 35 percent of the work done within collaborative teams comes from only 3 percent to 5 percent of the employees on the teams. And, boy, are they are getting grumpy and tired.

According to an article in the Harvard Business Review by three business school professors, this not only means your people are spending entirely too much time in "collaborative" meetings, but the top workers are burning out, slowing things down, and eventually checking out.  

"Performance suffers as [your employees] are buried under an avalanche of requests for input or advice, access to resources, or attendance at a meeting," says the report, written by Adam Grant, professor of management and psychology at Wharton, Rob Cross, professor of management at the University of Virginia's McIntire School of Commerce, and Reb Rebele, a Wharton researcher at the University of Pennsylvania. "They take assignments home, and soon, according to a large body of evidence on stress, burnout and turnover become real risks."

The authors found that over the past 20 years, the time your employees and managers spend working on "collaborative activities" has increased by 50 percent or more. The trio found that with the increase in collaboration, the time your employees spend in meetings, on the phone, and on email has shot up 80 percent, which doesn't leave much time for them to do the actual work.

Unfortunately, your most competent employees will do their best and managers from throughout your company will start to rely on their expanding roles and talents, the authors find. It's a combination of their "giving mindset and desire to help others" that leads to their reputation as "extra-milers."

But eventually, as the work piles on from different projects and different managers, these employees start to slow things down.

"We find that what starts as a virtuous cycle soon turns vicious. Soon helpful employees become institutional bottlenecks: Work doesn't progress until they've weighed in," they write. Worse, the study finds that these employees become so overtaxed that they're no longer personally effective. And more often than not, the volume and diversity of work they do to benefit others goes unnoticed, because the requests are coming from other units, varied offices, or even multiple companies.

The inevitable end game is that, on average, your most collaborative employees, who are seen as the "best sources of information," have the lowest engagement and career satisfaction numbers. The highest collaborators are more likely to leave the organization, or stay and spread a "growing apathy" to the other employees.

Grant, Cross, and Rebele say that while collaboration is needed to tackle the rush of work coming into your company, more collaboration doesn't translate into a better outcome.

"Leaders must learn to recognize, promote, and efficiently distribute the right kinds of collaborative work, or their teams and top talent will bear the costs of too much demand for too little supply," they write.