Think about how you are going to feel if you eat the healthy food, how you are going to look in a bikini next summer or in skinny jeans. Think about feeling strong, healthy, confident. You'll be more confident in the bedroom, more confident at the office.
To sing a song is quite different than to write a poem. I'm not and never will be a novelist, but to write a novel is not the same thing as writing a play. There is a difference in form, but essentially what you're after is the same thing.