Yes. This will effect your relationship. There’s a limited amount you can do about it since the problem resides inside of him, not in you or your behavior.
There is, however, one thing you can do: Remind him that there are many kinds of intelligence. You may be smarter when it comes to, say, academic work. But he’s the national-level sportsman. That’s another kind of intelligence — one you don’t have. Both of you could look at whether you each need to fine tune your emotional intelligence as well. Are you each being sensitive enough to each other’s insecurities? Have you found ways to comfort and support each other when those insecurities happen?
A good relationship is one in which each partner’s contributions are recognized and valued both by themselves and by each other. When people bring different kinds of intelligence to the relationship, they can make a team that is stronger than either person is alone.
If this explanation doesn’t provide enough help, I do think your boyfriend has some personal internal work to do. He has his self-esteem too tied up with being the best at everything. He needs to learn to value himself and to trust others who value him. Therapy is one route to self-acceptance. If that’s not available, encourage him to read books (or watch videos) about how to improve his self-acceptance and self-esteem.
I wish you both well.