Increase workout time
One study confirms that working out with a friend significantly increases time you spend exercising. A study by the Society of Behavioral Medicine found that working with another person, improved performance and doubled the length of time of those who exercised alone.
Additionally, researchers at Kansas State University discovered that people who exercised with a partner they perceived to be better than them increased their workout intensity and time by 200 percent.
"We found that when you're performing with someone who you perceive as a little better than you, you tend to give more effort than you normally would alone,” says Brandon Irwin, principle researcher in the Kansas State University study. “In certain fitness goals, like preparing to run a marathon, consider exercising not only with someone else, but with someone who is that much better."