When we watch the top athletes at the Olympics, we take it for granted that they all have coaches. We see so many pictures of the athlete leaving the field and walking straight into the arms of a coach that we stop seeing them. We don't take the message that people who have reached the very top levels of performance at relatively simple activities still need a coach (when you compare even the most complicated sports to teaching a classroom or running a company, you'll find that the sports involve many fewer variables).
Coaches provide two things that the athlete cannot have in the same way: experience and perspective. If it is not practical for you to have a coach available to you whenever you need to hit your best performance, then you need to think about how to reach the best resources in your own experience and how to stretch your perspective.
Here's the rub: when you have looked with "a colder eye" at your own performance state, you will suspect that it could be fine-tuned, that it would benefit from some ruthless editing, that it could be stronger and more sustainable. And you will pull back, viscerally, from making changes in the state that has driven your best achievements. Your eye and your gut will have strongly different opinions.
The coach has an alternate state of experiences that allow him/her to negotiate (not necessarily resolve) this difference. You only have your own experience. It takes huge will power to decide that you are going to plow through this really basic incongruence to go from good to better. Your instincts won't support you because your instinct is to do what you have done to get what you have gotten.
If you don't have a coach, you need friends and anchors and external support. You need limits on the extent to which you are willing to be self-destructive in order to build a stronger, more resilient, more elegant - SELF. You need to protect the seeds of yourself so that whatever happens, good or bad, you can grow again when necessary.
Change is easy when it means moving from bad to good. When it means moving from something that is working to something that we only hope will work better, change is really, really hard. Being better than your current best is hard.
I congratulate every athlete who experienced a personal best at the Olympics. But if you are reading this and working alone on a difficult change, know that I am also cheering for you. What you are doing is hard and brave and worthwhile and possible. Climb up into the stands and watch with me for awhile. See what I see. Then take that perspective back onto the playing field and do what you need to do to do better than your best.