How do I work so that I look really toned when hiking in the woods?

[guitarguy]

I'm a runner on my track team and I'm not exactly satisfied with my upper body. Don't get me wrong, I'm fit and all, but I'm looking to get toned for when I return for cross country in the fall. I am going a hike across the Appalachian trail this summer and it is going to span about 100 miles. What could I do to improve my core and arms so that I both feel strong and look toned. And what should I follow up with once I get back home so I can stay in shape? I'm not trying to look ripped out of my mind like a body builder in the mr. universe pageant or anything but I want to look really good, this is mainly for my own personal health and fitness