CEOs reveal how they train their bodies and minds for the ‘marathon’ job, from playing chess to ‘energy management’

• In today’s CEO Daily: Diane Brady shares how today’s leaders stay mentally and physically fit.
• The big story: Iran shuts down its internet amid protests.
• The markets: Mostly up, with U.S. futures inching higher.
• Plus: All the news and watercooler chat from Fortune.

Good morning. How are those New Year’s resolutions coming? In talking to hundreds of leaders every year, one thing I’ve been struck by is how disciplined they are about making time to take care of themselves.