After compiling several year’s worth of data, a study from MIT Sloan professor Sinan Aral and postdoc Christos Nicolaides found that exercise is indeed socially contagious. Aral says, “Knowing the running behaviors of your friends as shared on social networks can cause you to run farther, faster, and longer.”
The study, formally published in Nature Communications, entitled “Exercise Contagion In A Global Social Network,” is a “watershed moment in the use of detailed fitness tracking data to understand health behavior and causal behavior change.” Aral and Nicolaides analyzed a data set comprised of the “geographic location, social network ties and daily distance, duration, pace and calories burned” of over one million runners who ran a combined total of 223 million miles over a five-year period.
Aral says the study shows that, “On the same day, on average, an additional kilometer run by friends can inspire someone to run an additional three-tenths of a kilometer. An additional ten minutes run by friends can inspire someone to run three minutes longer.”
Historically, in the context of exercise, a debate exists about whether we make upward comparisons to those performing better than ourselves or downward comparisons to those performing worse than ourselves. Comparisons to those ahead of us may motivate our own self-improvement, while comparisons to those behind us may create “competitive behavior to protect one’s superiority.” According to Aral, there is evidence for both trajectories in the study, but comparisons to those better than us are more powerful.
Aral also notes an interesting gender component to the study in which the “contagion is most pronounced among men, with men influencing other men to run farther and faster.” While “both men and women influence men, only women influence women who have reported, in earlier studies, being more influenced by self-regulation and individual planning than by their peers.”