India, July 11 -- To anyone dropping in to the India Post office at Delhi's Connaught Place, Mohit Khatri, 27, will seem like an ordinary employee. He spends most workdays making entries in a register and tracking parcels. But look closer. At 5'8", muscles straining against his shirt, Khatri seems much too well-built for the job. He seems much too focused too. It's like spotting Clark Kent after you've watched the Superman movie. Something isn't quite adding up.

All this depends, of course, if you spot Khatri at the post office at all. He does lead something of a double life. In his Superman avatar, Khatri serves as captain of Indian Rugby 7s, and has also led his state team of Haryana to three rugby championship wins. At the moment, he'...