Jeffrey Kindler, who stepped down as Pfizer Inc.'s chief executive on Sunday, citing burnout, is the rare CEO to say that the job wore him out.

In fact, occupying the high-powered cocoon known as the corner office is more stressful than ever, thanks to a greater emphasis on globalization, stiffer competition, heightened government regulation and the weak economic recovery, say former CEOs, corporate directors and management experts.

Compared with four years ago, pressures on CEOs 'are substantially different -- especially in certain industries,' said Steve Reinemund, who retired in 2006 as PepsiCo Inc. CEO 'It's still pretty tough out there,' adds Mr. Reinemund, dean of Wake Forest University's business school.

As a result, many CEOs now look at the corporate throne 'as a position with a limited term of office,' said Jeffrey Sonnenfeld, a senior associate dean at Yale University's School of Management. 'They rarely seek to stay a minute more than a dignified decade.'

To cope, a few CEOs cut short their tenure. The head of a mid-sized mutual insurance company intended to retire in early 2013 after serving since 1999. But during a board succession-planning session three years ago, this chief announced he felt 'frankly burned out' and wanted to leave within a year, said Beverly Behan, a New York corporate-governance consultant. 'It was the most emotional board meeting I had ever been in,' she added.

His announcement forced the board to accelerate its succession timeline. But an internal candidate wasn't ready to take command. So the burned-out CEO ran the business until early 2010, said Ms. Behan, who declined to name the executive or company.

Some corporate directors monitor whether the No. 1 executive is working too hard. While Daniel Vasella ran Novartis AG, 'we were concerned he was travelling around the world all the time, and it was affecting his family life,' recalled William W. George, a former director of the drug maker who led Medtronic Inc. until 2001. 'We said, 'Make sure you take care of yourself.' He monitored it [his travel] better,' said Mr. George, now a Harvard business school professor of management practice. Mr. Vasella remains Novartis chairman.

A U.S. spokeswoman for Novartis said late Monday that Mr. Vasella couldn't be reached for comment in Switzerland.

Mr. George still serves on the boards of Goldman Sachs Group Inc. and Exxon Mobil Corp., where he said independent directors often privately discuss the pressures facing their CEO. 'The job is a lot more stressful than when I had it,' he said.

Executive recruiters also measure CEO candidates' ability to handle stress. Joseph E. Griesedieck Jr., a vice chairman of search giant Korn/Ferry International, said he assesses how well prospects deal with stressful situations. 'You look for the person's ability to accept new challenges by measuring their learning agility and ability to deal with complexity,' he said.

Michael Bonsignore, retired CEO of Honeywell International Inc., suggests that stressed-out corporate leaders exercise vigorously. Without his own 45-minute daily regimen, 'I don't think I would have been as effective,' recollects Mr. Bonsignore, who stepped down in 2001.

金德勒(Jeffrey Kindler)周日以劳累过度为由辞去了辉瑞制药有限公司(Pfizer Inc.)首席执行长(CEO)的职务，他说这份工作让他精疲力竭，而此前很少有CEO会这样讲。

多Associated Press金德勒(Jeffrey Kindler)位前CEO、公司董事及管理专家说，鉴于业务全球化的重要性增加、市场竞争更加严峻、政府监管进一步加强以及疲弱的经济复苏形势，现在要承担这个责任重大的CEO职务所面临的压力比以前要大得多。

2006年退休的前百事公司(PepsiCo Inc.)首席执行长瑞尼蒙德(Steve Reinemund)说，目前CEO面临的压力与四年前相比明显不同，在一些特定行业尤其如此。现任维克森林大学(Wake Forest University)商学院院长的瑞尼蒙德补充说，现在CEO的处境十分艰难。

耶鲁大学管理学院(Yale University's School of Management)资深副院长索诺菲德(Jeffrey Sonnenfeld)说，很多CEO因此把公司首席执行长这一宝座看成是“一个任期有限的职位”，创造出十年的光辉业绩之后，现在已很少有人会愿意在这把交椅上再多坐一分钟。

为此，一些CEO将自己的任期缩短。纽约一位提供公司治理咨询服务的顾问贝安(Beverly Behan)说，某位自1999年以来就担任某中等规模的互助保险公司CEO一职的人士本打算2013年初退休，但三年前在该公司董事会继任规划会议上，这位CEO坦言自己“累垮了”，希望一年内辞职。贝安补充说，这是自己参加过的最感情冲动的一个董事会议。

这位CEO宣布退休的决定迫使该公司董事局加紧制定CEO继任时间表，但公司内部一个候选人却没有对就职做好准备。贝安说，于是这位累垮掉的CEO直到2010年初才得以卸任。她拒绝透露这位CEO的姓名以及该公司的名称。

还有些公司的董事会监督身为公司一把手的CEO是否工作过于努力。诺华制药公司(Novartis AG)前董事乔治(William W. George)回忆说，该公司前首席执行长魏思乐(Daniel Vasella)任职期间总是在世界各地拼命出差，我们为他感到担心，再说这也影响到其家庭生活。乔治曾担任美敦力公司(Medtronic Inc.)的CEO，2001年辞职。乔治说，我们对魏思乐讲，一定要保重身体，此后他才开始注意减少出差。乔治现在是哈佛商学院(Harvard business school)管理实践学教授，而魏思乐仍是诺华制药的董事长。

诺华制药美国发言人周一晚间说，无法联系到身处瑞士的魏思乐做出置评。

乔治目前仍是高盛集团(Goldman Sachs Group Inc.)和埃克森美孚(Exxon Mobil Corp.)两大公司的董事会成员。他说，埃克森美孚的独立董事常在私下讨论公司CEO面临的压力，这种压力比我当年做CEO时要大得多。

另外，猎头公司也会判断CEO候选人的抗压能力。全球首屈一指的猎头公司光辉国际(Korn/Ferry International)其副董事长Joseph E. Griesedieck说，他会评估候选人如何处理压力情况，因为CEO要有迎接新挑战的能力，所以要衡量候选人的学习灵活性与处理复杂情况的能力。

美国霍尼韦尔(Honeywell International Inc.)已退休的CEO邦西格诺(Michael Bonsignore)建议压力过大的公司高管要积极锻炼身体。2001年辞职的邦西格诺回忆说，要不是因为每天坚持锻炼45分钟，我觉得自己的工作效率不会如此之高。