As if the marathon was not enough, endurance runners upped their ante with multiple versions of the 42.195K running format. Road, off-road, and trail are some of the cocktail mix of terrain they have tossed in, to test the mettle (and values) of the runner. Here is one such race that is becoming popular among seasoned and serious runners. I did the 50K last year with a partner, whereas there is a Solo 100K personal challenge. MR25 Runners have an annual ultra-marathon which requires a minimum commitment of five loops of 10.5K (52.5K total) or as many loops you can complete from 7.00am till 7.00pm (12-hours limit) at the Macritchie Reservoir. May you decide, plan and train well!