Re: hiking poles
They also can help prevent twisted ankles. A few times, stepping on an unexpected rock or loose one, or if my foot slipped a bit, I easily transferred my weight to my hiking poles and prevented a painful bend or twist of my ankle. I was not expecting the poles to be as helpful as they turned out to be.
As for food, I had three sandwiches, made with sliced toast and either PB&honey, ham or roast beef slices. I would have been fine with two, but the third one sort of distracted me from the long track back from the switchbacks to Lone Pine Lake. I started with 6 Cliff bars, 3 Kind bars, three sandwich-size bags of gorp, and a bit more. I brought back 3 Cliff bars, 2 Kind bars, and all the gorp.
The extra pain on my shoulder muscles where the backpack straps were being supported (I did have hip support on that backpack, but maybe not the best for my short stature), would have been less if I can figure out how to pack 10lbs less.
I noticed a lot of people doing the day hike with what seemed to be just hydration packs and the limited storage those provide.