Sajan Prakash is obsessed with the idea of getting better by one second these days. One second better than his personal best time in the 200m butterfly event, which came five years ago. Every time he plunges into the pool or enters the gym, a time of around 1:55 is on his mind. For, if he can better his best (1:56.38) by just one second, he walks off from the Glasgow Commonwealth Games in July-August with a medal around his neck. The 32-year-old believes this will likely be his final year as a competitive swimmer. So, he is determined to go out with a podium finish. The one-second math in his mind is simple: in Birmingham four years ago, James Guy won bronze clocking 1:56.77, Chad le Clos took silver with 1:55.89 and Lewis Clareburt raced away to gold in 1:55.60. At the recent Singapore National Age Group Swimming Championships, Sajan claimed a silver medal with 1:57.09. So, he spent all of the last few weeks averaging between 60 to 70 kilometres in the pool.…