A study says social media makes exercise 'contagious'. Researchers found that people who put details of their exercise on social media motivate other people to exercise more. Researchers tracked 1.1 million runners over a five-year period. They looked at the runners' social network use, distance, time, speed and calories burned. They concluded that sharing exercise data on social media inspires others to exercise more, harder and more competitively.

The study has reports of how reading about a friend's exercise can be inspiring. It said an extra kilometre run by friends can inspire someone to run three-tenths of a kilometre farther, and an extra ten minutes run by friends can inspire someone to run three minutes longer. Social media improved slower, less in shape runners, and those who were showing signs of overtaking a friend. If you run more, it is likely that you can make friends run more.