New Zealand PM Jacinda Ardern's resignation shows burnout is still going strong. Here's how to know when you're there and why calling it quits might be the right thing.

• The resignation of New Zealand PM Jacinda Ardern is shedding light on burnout among top global leaders.
• "I no longer have enough in the tank to do the job justice," Ardern said on Thursday.

When New Zealand Prime Minister Jacinda Ardern resigned this week, saying she no longer had "enough in the tank to do the job justice," many were left shocked.

"You cannot and should not do the job unless you have a full tank, plus a bit in reserve for those unplanned and unexpected challenges," Ardern said Thursday.

While her announcement may have stunned some, it's shedding new light on how common burnout among government and business leaders is — and how tricky it can be to identify.

Her departure comes as global executives have started speaking out against burnout, taking a cue from the sea of workers who left jobs during the pandemic as part of The Great Resignation. According to a Deloitte survey of a C-suite executives published in July, 69% of respondents said they are seriously considering quitting for a job that better supports their well-being.

Here's how to assess burnout and recognize when it might be time to hit the road, according to experts.

When it's more than just exhaustion

Robyn Montgomery, a life coach who specializes in burnout, described Ardern's resignation as "a beautiful example of what it means to be human" that shows that quitting is sometimes the best move — not just for yourself, but for your colleagues, constituents, and clients.

"From a leadership perspective, if you are experiencing burnout, if you are feeling more exhausted than energized in your work, and you're not recharging at the rate that you want to be recharging at, it's going to be very difficult to show up in your role as who you want to be," Montgomery said.

And while occasional fatigue is normal, when you're chronically waking up depleted and unmotivated, it's time to take stock, according to Michael Leiter, co-author of "The Burnout Challenge: Managing People's Relationships With Their Jobs."

"If you're constantly feeling tired before the day begins, you just can't find the energy, the spark, the effort to do it, that's one of the signs that you're definitely at least overextended and maybe headed towards burnout," Leiter told Insider.

Identifying professional burnout also means knowing when "continuing to work in that circumstance is actually destroying value to the company or to the organization, rather than creating it," said Josh Merrill — co-founder and CEO of Confirm, which helps companies improve performance reviews.

"That happens when people are exhausted, but they still have all the same responsibilities or they're having to do more with fewer resources," Merrill told Insider. "And I think that does cause people to make decisions that are suboptimal, that are made from compromised mental or emotional states, and that leads to suboptimal outcomes."

Knowing when to call it quits

Montgomery said there's no catch-all approach to identifying burnout so the best move is to trust your gut.

"In terms of signs, it is different for different people and the most important thing is to listen to your gut," she said. "It's really about listening and supporting yourself at the highest level in order to be able to really get to the root cause."

"When you've reconciled the experience and determined for you that staying will cost more than you have or you're willing to give, that's when I would say that quitting might be something to consider."

According to Leiter, quitting takes bravery, but also can lead to new opportunities and a better future.

"Quitting is a gutsy thing to do because you have to have that confidence to think, 'I can quit this job and I'm going to land on my feet. Life's going to be good, more opportunities are going to come my way.' That's a strong position to be in," he said.

The future of burnout

Merrill said he anticipates the widespread burnout that arose during the pandemic intensifying, particularly in the wake of recent mass layoffs in the tech and finance industries.

"We have more and more being asked of top performers to carry the burden as workforces shrink, and burnout is happening in those settings," he said. "The reality is that burnout really happens in the shadows. It happens quietly. And then before anyone can do anything about it, it's too late and, and the person decides to move on."

Leiter offered a more optimistic view, noting that the pandemic helped empower workers to set boundaries, or shift to hybrid or remote working that may help prevent overexertion.

"The pandemic showed work can change drastically if it really has to," he said. "It changed so that a lot of the hard and fast rules about when and how you work are really fairly arbitrary. Now you can do all kinds of things which seemed impossible before, and I think that opens up a lot of possibilities."

It's important to remember workers are more than just cogs, Montgomery said.

"We have to remember that people are not machines. We're all human first, all of us, and we work and recharge in different ways, and each of us has something brilliant to offer."