Margalla Backyard Ultra (MBU) is the 1st ever Backyard Ultra in the history of Pakistan and it is the only Backyard Ultra in Pakistan. Backyard Ultra is a form of ultramarathon race where competitors must consecutively run the distance of 6.706 kilometers (4.167 mi) in less than one hour. They must repeat this every hour until only one person completes a full lap – the last one standing.