A study published in scientific journal Nature Communications found that friends play a major role in determining a person's exercise routine, according to The Independent. 

Spanning over five years, the study tracked the daily exercises of over a million people in a global social network of runners and found that exercise patterns were largely influenced by those of others. 

Research showed that men are easily influenced by both genders, while women seemed to be influenced by those of the same gender alone. This may seem fairly obvious, due to the "gender difference in the motivation for exercise and competition," says authors of the study, Sinan Aral and Christos Nicolaides. However it was interestingly noted that less active runners influence more active runners. 

These results suggest interventions that account for social contagion will spread behaviour change more effectively.

“For example, men report receiving and being more influenced by social support in their decision to adopt exercise behaviours, while women report being more motivated by self-regulation and individual planning,” they wrote.

Through the use of an exercise tracker, participants could instantaneously observe via social media platforms when their peers went for a run.

This study also shed light on the competitive streak most participants held when comparing their activities to those of their peers. This was seen through participants upping their distance and intensity simultaneously to others they observed.

Despite defining the study as "suggestive", researchers conclude that “these results suggest interventions that account for social contagion will spread behaviour change more effectively.”