India, Sept. 23 -- Sachin Nag was ten when he led the police away from his freedom-fighter older brother, Bholanath, and jumped into the Ganges. Coincidentally, a 10km swimming race was underway. He slipped into the stream of swimmers and ended up finishing third.

In 1951, at the inaugural Asian Games in New Delhi, Nag won the 100m freestyle. Seventy-five years later, it remains the only swimming gold India has won at the Games.

Nag was born in Varanasi in 1920 and moved to Calcutta in 1937. Swimming then bore little resemblance to the world of temperature-controlled pools, biomechanical analysis and hydrodynamics we know today. Nag made do.

At Deshbandhu Park, where he trained, he nailed wooden planks against the walls of the pond so ...