When I’m on the sixth kilometre of a long run, the last thing I want to do is smile. But the author of Slow Jogging: Get Fit, Lose Weight, Stay Healthy, and Have Fun With Easy Running, Dr Hiroaki Tanaka, said that’s what I should aim for to achieve a healthier, happier run. He recommended trying a “smiling” or “niko niko” pace for better blood pressure and increased fitness. Science says runners can seriously benefit from the practice, which has helped to get me back into running after a long break. What is “niko niko” pace? It means a “smiling” pace (“niko” means smiling in Japanese). In other words, it’s a slow, easy pace. So much so, Dr Tanaka told the Sydney Morning Herald back in 2016, that you can “talk at ease, or if you are running alone, sing your favourite songs”; it can start as slow as three to five kilometres an hour, though everyone’s different. More experienced runners might plod along at seven kilometres an hour. What are the benefits of “niko …