Haru's request to wait a year is very selfish. It is not as if she has been drafted into military service. She is just a little bit busy, and it would be more convenient for her if she didn't have to make time for him. If track and field is more important to her than Eiyuu, then I see no reason...
While he may not be interested in her romantically; that doesn't mean he is being honest about his feelings. He won the competition for her sake, and he is pretending like that is not the case.