I'm not aware of a study focusing on this area, but from personal experience there's a few things to consider. Most coaches will advise athletes to focus on areas they can control and take ownership of. Examples are sleep, nutrition, hydration, consistency over time etc. By focusing on areas within their control, it helps prevent athletes from wasting emotional energy on areas they have no control over. The response about checking the weather before heading out is a good one. I had an athlete who represented the US at the World Championships in the marathon who really hated running in the rain. The fortunate thing for her is that it rains very little in our area. But if the forecast for the day included rain, she would watch the doppler religiously trying to determine when she would go out and complete her run or runs for the day and stay out of the rain if at all possible. She took control of when she ran taking into account something out of her control which was the weather.
Another consideration is the experience of the athlete. When an athlete is new to a sport, they are really overwhelmed by the mountain of information to be processed - what's important and should be focused on vs what is relatively unimportant and should be brushed aside? I ran my first marathon in 1977 and was a competitive runner in HS, college and after college until the late 90's, so essentially 30 years of competitive running which results in a lot of experience versus someone who is new to the sport and looking to complete their first marathon. A study looking at external stress using me and my old training buddies as the test group would likely result in much different results than those using runners with less than a year's experience. As you gain experience you tend to become more internally focused and trust your gut. You have a much better sense of what is important to long term success and achieving your goals. Inexperience generally results in athletes second guessing themselves - "Am I doing the right thing?" and using external cues to a much greater extent to guide their decisions. In the rain example above, I probably would have cut the run short if lightning was coming and try again later in the day or later in the week. If you're less experienced and the program calls for 18-20 miles on Sunday, you do it regardless of what stresses get in your way which can result in running in a thunderstorm or trying to train through an injury to continue following a program instead of backing off and addressing the injury so you can come back stronger and healthy another day.
Joe