India, Jan. 28 -- Indian-origin CEO Karun Kaushik was recently left in awe by the "impromptu-marathon level action" of his co-founder, Selin Kocalar. After noticing a rare "Out of Office" tag on her calendar, Kaushik learned that Selin was flying 16 hours from San Francisco to Morocco just to run a marathon. True to her high-speed work ethic, she completed the race and returned to the office on Monday morning, suitcase in hand, proving that for some founders, the ultimate "fun" is a test of extreme endurance.

I flew to Morocco for 36 hours over the weekend to run the Marrakech Marathon and then come right back to the office. Founder definition of fun," tweeted Kocalar.

"Meet the single craziest and most determined person I've worked wit...