The first point I would make about this question is that self-doubt affects everyone at some stage. For triathletes it is common especially if you are trying out a new distance or if you are racing in an event where you are aiming to qualify for a championship or set a PB. It can also set in when you are trying something new like open water swimming. In my experience, self-doubt commonly appears when you are under-prepared.
For example, let’s say an athlete is stepping up to the 70.3 distance for the first time. When they enter the event it’s a scary goal, but with a few months of training they could prove to themselves that it is possible for them to complete each of the distances and inside the cut off times. By the time they get to race day it is still a new experience, but knowing that they have done everything in their power to achieve their goal should be enough. So the key element here then is preparation.
Here is one approach you can try, which I call leaving “no stone unturned”:
Make a list of everything that you would like to do before race day.
For the 70.3 example above it might include the following:
- Swim 1900m inside 60 mins
- Ride 56 miles at an average of 16mph
- Run (or run/walk) 21k in under 2hrs 30
After this you could go deeper if you have specific concerns, for example:
- Swim in open water similar to the race venue (sea, lake, river)
- Improve hill climbing ability
- Lose 10kg to get to race weight (this means sharpening up your diet, it does not mean a fad diet or drastic measures)
- Stay health and injury free (this requires an understanding of why you get ill or injured and then how to prevent either)
- Get a bike fit (to be more aerodynamic and thus faster)
The list will go on until you have itemised all of your potential concerns. Your goal is to stand on that start line and know that you could not have done any more. That way you will have eliminated the majority of your self-doubt.
On your journey there will be other moments of self-doubt and these are usually based on the outcome (the result you are hoping for). If you can divert your focus to the process (the actions you are going to take to achieve your goal) and use some positive self-talk, then you will find some comfort. For example, “I’ve done this many hundreds of times in training, I know I can run at the speed I need to hit my goal”, etc.
Not being entirely certain is part of the reason why we do this: To try and find out exactly where our limits are. Even not making it has no shame attached. Better to fail trying than never to have tried. And failure (if it is failure) provides lessons for the future upon which success is built. If at first you don’t succeed . .
Best wishes and keep on trying!