It is to compete against oneself.
You still win, which is the aim of any competition. You win over yourself.
You still get better after each completion.
But more importantly, others will help you, cheer for you and support you.
If you’re in school, you compete with your classmates but you can choose to compete against yourself at the tests.
In a race, you try to reach the finish line before other contestants. But you can also choose to beat your last training.
A better way to compete then is against yourself.