Claudia Pechstein, just under a month before her 51st birthday, defended her 5,000 metres title at the German speed skating championships in Erfurt on Saturday. The Berliner, a five-time Olympic gold medallist, has kept on competing well beyond the age speed skaters usually retire. She first medalled at an Olympics way back in 1992. Pechstein was accused of blood doping in 2009 and was banned from all competitions for two years. She has continually protested her innocence and embarked on a long legal battle to seek damages. Losing out on two years of her career is one of the reasons for her dr…