Recently, there was a huge debate in the scientific community on Irisin, the exercise hormone. Irisin is a hormone produced by exercise; discovered in 2011 and published in early 2012 in Nature amidst resounding hype and adulation. It created a buzz among scientists and exercise enthusiasts as a substance that could convert white fat into brown fat (brown fat being ‘good’ compared to white fat). It held the potential for weight loss and a host of other problems. We had reported in March 2015 that a group of scientists had questioned the very existence of Irisin; Irisin was described as a myth.