Chose organic, non-GMO, non processed, no chemicals or artificial additives, no high fructose corn syrup. That leaves organic and fresh. support your local organic farmer as much as possible, that way you know where the food came from and keeps them going. That is a good thing.
The thing I love about this is that it doesn't even need to apply to the physical. Yes, my thing could be completing a marathon or climbing a mountain, but it could also be changing my major or moving across the world. I could make them all gasp, one day.