While engagement certainly has its benefits, most of us will have noticed that, when we are highly engaged we can also experience something less than positive: high levels of stress. A recent survey conducted at Yale University examined the levels of engagement and burnout in over 1,000 U.S. employees. For some people, engagement is indeed a purely positive experience; 2 out of 5 employees reported high engagement and low burnout. However, the data also showed that one out of five employees reported both high engagement and high burnout. These engaged-exhausted workers were passionate about their work, but also had intensely mixed feelings about it – reporting high levels of interest, stress, and frustration. These apparent model employees also reported the highest turnover intentions in the sample – even higher than the unengaged group.

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Dorothea loved her new workplace and was highly motivated to perform. Her managers were delighted with her high engagement, professionalism, and dedication. She worked long hours to ensure that her staff was properly managed, that her deadlines were met, and that her team’s work was nothing short of outstanding. In the first two months, she single-handedly organized a large conference – marketing and organizing all the details of the conference and filling it to capacity. It was a remarkable feat.

In the last weeks prior to the event, however, her stress levels attained such high levels that she suffered from severe burnout symptoms, which included feeling physically and emotionally exhausted, depressed, and suffering of sleep problems. She was instructed to take time off work. She never attended the conference and needed a long recovery before she reached her earlier performance and wellbeing levels. Her burnout symptoms had resulted from the long-term stress and the depletion of her resources over time.

Engagement means flourishing, or does it?

Employee engagement is a major concern for HR leaders. Year after year, concerned managers and researchers discuss Gallup’s shocking statistic that seven out of 10 U.S. employees report feeling unengaged. Figuring out how to increase employee engagement has been a burning question for companies and consultants across the board.

The many positive outcomes of engagement include greater productivity and quality of work, increased safety, and employee retention. These outcomes are in fact so well established that some researchers like Arnold Bakker, Professor of Work and Organizational Psychology at the Erasmus University Rotterdam, and colleagues have linked engagement to the experience of “flourishing at work.” Similarly, Amy L. Reschly, Professor of Educational Psychology at the University of Georgia, and colleagues concluded that student engagement at schools was a sign of “flourishing.”

While engagement certainly has its benefits, most of us will have noticed that, when we are highly engaged in working towards a goal we can also experience something less than positive: high levels of stress. Here’s where things get more nuanced and complicated.

A recent study conducted by our center at Yale University, the Yale Center for Emotional Intelligence, in collaboration with the Faas Foundation, has cast doubts on the idea of engagement as a purely beneficial experience. This survey examined the levels of engagement and burnout in over 1,000 U.S. employees. For some people, engagement is indeed a purely positive experience; 2 out of 5 employees in our survey reported high engagement and low burnout. These employees also reported high levels of positive outcomes (such as feeling positive emotions and acquiring new skills) and low negative outcomes (such as feeling negative emotions or looking for another job). We’ll call these the optimally engaged group.

However, the data also showed that one out of five employees reported both high engagement and high burnout. We’ll call this group the engaged-exhausted group. These engaged-exhausted workers were passionate about their work, but also had intensely mixed feelings about it — reporting high levels of interest, stress, and frustration. While they showed desirable behaviors such as high skill acquisition, these apparent model employees also reported the highest turnover intentions in our sample — even higher than the unengaged group.

That means that companies may be at risk of losing some of their most motivated and hard-working employees not for a lack of engagement, but because of their simultaneous experiences of high stress and burnout symptoms.

How to maintain high engagement without burning out in the process

While most HR efforts have stayed centered around the question of how to promote employee engagement only, we really need to start taking a more nuanced approach and ask how to promote engagement while avoiding burning out employees in the process. Here’s where key differences we found between the optimally engaged and the engaged-exhausted employees can shed some light.

Half of the optimally engaged employees reported having high resources, such as supervisor support, rewards and recognition, and self-efficacy at work, but low demands such as low workload, low cumbersome bureaucracy, and low to moderate demands on concentration and attention. In contrast, such experiences of high resources and low demands were rare (4%) among the engaged-exhausted employees, the majority of whom (64%) reported experiencing high demands and high resources.

This provides managers and supervisors with a hint as where to start supporting employees for optimal engagement. In order to promote engagement, it is crucial to provide employees with the resources they need to do their job well, feel good about their work, and recover from work stressors experienced through work.

Many HR departments, knowing employees are feeling stressed, offer wellness programs on combating stress – usually through healthy eating, exercise, or mindfulness. While we know that chronic stress is not good for employees, company wellness initiatives are not the primary way to respond to that stress. Our data suggests that while wellness initiatives can be helpful, a much bigger lever is the work itself. HR should work with front-line managers to monitor the level of demands they’re placing on people, as well as the balance between demands and resources. The higher the work demands, the higher employees’ need for support, acknowledgement, or opportunities for recovery.

What about stretch goals? Challenge, we’re told, is motivating. While that can be true, we too often forget that high challenges tend to come at high cost, and that challenging achievement situations cause not only anxiety and stress even for the most motivated individuals, but also lead to states of exhaustion. And the research on stretch goals is mixed – for a few people, chasing an ambitious goal does lead to higher performance than chasing a moderate goal. For most people, though, a stretch goal leads us to become demotivated, take foolish risks, or quit.

Managers and HR leaders can help employees by dialing down the demands they’re placing on people – ensuring that employee goals are realistic and rebalancing the workloads of employees who, by virtue of being particularly skilled or productive, have been saddled with too much. They can also try to increase the resources available to employees; this includes not only material resources such as time and money, but intangible resources such as empathy and friendship in the workplace, and letting employees disengage from work when they’re not working. By avoiding emailing people after hours, setting a norm that evenings and weekends are work-free, and encouraging a regular lunch break in the middle of the day, leaders can make sure they’re sending a consistent message that balance matters.

The data is clear: engagement is key, it’s what we should strive for as leaders and employees. But what we want is smart engagement — the kind that leads to enthusiasm, motivation and productivity, without the burnout. Increased demands on employees need to be balanced with increased resources — particularly before important deadlines and during other times of stress.

Editor’s note: We’ve updated the headline to clarify the statistic in it.