Jim Weber, CEO Brooks Running

Jim Weber, the longtime chief executive of Brooks Running, was for many years a devoted runner. The hours spent racking up the miles were more than exercise for him. They were a chance to meditate on life, to devise strategy about business, and to ruminate on the thorny problems that come with operating a company with more than $1 billion in annual sales.

Then, a few years ago, Mr. Weber got cancer. He had to step away from running the business, endured difficult rounds of treatment and emerged cancer-free β€” but missing a lung.

Mr. Weber, who has been C.E.O. for more than two decades β€” steering it from near bankruptcy, through private equity ownership, out from being a subsidiary of Fruit of the Loom, and into being a stand-alone part of Berkshire Hathaway β€” is still enjoying what he calls his β€œdream job,” with no plans to retire.