It's simple whether that you walk to work, or you take 20 minutes during your lunch break to walk around the gorgeous campus or town that we are live in.
And knowing the competitive culture of Silicon Valley, I doubt that any of the Yahoo employees working from home are limiting themselves to four hours of work before lunch and four after.
After being sued repeatedly for allegedly forcing employees to work through lunch and bathroom breaks, the company installed computer systems that shut down individual cash registers when workers were scheduled for breaks.