My aversion to “going out for a friendly group run” stems from my first week of high school. I had just moved to a new city and was trying to make friends in a school of 4,000 kids. A classmate invited me to try out for track. I was a horrible runner, but didn't want to turn down the friendly offer — so, I tried out. It was a disaster, complete with blisters, blood, and probably a few tears; I was in physical and emotional pain.
Despite the fact my running has improved, I'm still haunted by feelings of inadequacy. I don't find group runs fun or motivating, because the entire time I'm focused on my anxiety (am I slowing down the speedier runners?) instead of just enjoying how great it feels to move. There’s also the issue of scheduling: During the sliver of time I’m able to set aside for working out, I want to be able to push myself to my limits, which may or not be the same as the limits of the person I’m trying to exercise with.
There are plenty of studies that highlight the benefits of exercising with friends; researchers from the University of Southern California found that people enjoyed exercise more when they did it with buddies — and we all know that when you enjoy doing something, you're more likely to stick with it. Two different studies looked at training with a virtual partner and found that even imaginary friends motivate us to work harder and perform better.
I completely understand that working out with a pal can tap into your competitive drive, increase your accountability, and boost willpower. But, personally, I enjoy my workouts best (and find them the most effective) when I rely on myself for those things. Plus, fitness gadgets and apps make performance-tracking a breeze, so I always have a new goal to work towards. To make fitness part of your lifestyle, you have to find what works for you. For me, that means socializing and exercising don't mix.