During the 19th Century, the activity of “retro-walking” was little more than an eccentric hobby, but today research is revealing it can have real benefits for your health and brain. On an apparent wager to win $20,000 (about £4,250 at the time), a 50-year-old cigar-shop owner called Patrick Harmon embarked on a curious challenge in the summer of 1915 – he planned to walk backwards from San Francisco to New York City. With the aid of a friend and a small car mirror attached to his chest to help him see where he was going, Harmon made the 3,900 miles (6,300km) journey in 290 days, apparently walking every step backwards.