New US research suggests that having a large network of friend can be a good influence on your fitness.
Led by Greg Ver Steeg from the USC Viterbi School of Engineering's Information Sciences Institute and Department of Computer Science, Ver Steeg started his research after a 2007 study suggested that obesity might be contagious.
Wondering if positive health traits such as fitness could also be contagious, Ver Steeg partnered up with Google and Evidation Health, a company that aims to quantify health outcomes using digital technology, to explore the issue further.
Together the research team analyzed more than 44,000 Fitbit users, finding that people with larger and more active social circles have higher levels of physical activity.
In fact, for each additional social relationship, participants walked an average of 6.5 more steps.
However, after looking at the reason behind the findings the team were unable to determine what exactly was causing the relationship.
The researchers found some evidence for a causal link, but they also couldn't discount other factors that might influence the results, such as good weather causing people to spend more time outside and get fitter as a result.
Ver Steeg also created a mathematical model to rule out homophily, the idea that people who are active will tend to be friends with other active individuals.
As part of the study the team also looked at the relationship between social networks and physical activity for those with chronic conditions.
"When you're burdened by a chronic condition, your social network may have an especially high influence on your behavior," said Luca Foschini, co-founder and chief data scientist at Evidation. Users with chronic diseases might have more overlap between online and offline friend groups.