San Antonio Spurs' Tim Duncan is a physical specimen.
At age 37, one would think he would be a shell of his former self but he is still one of the premier big men in the NBA and is still producing at a high level for San Antonio. Last season, he averaged 17 points and 9.9 rebounds and helped guide the Spurs to their fifth NBA Finals appearance.
But before his impressive performance in the 2012-13 season, he felt he was on the decline and that his best days were behind him.
In an interview with ESPN, Duncan spoke about how staying in shape staved off the ravages of time on his body and spoke on how much longer he will play in the NBA.