"does ensure work as a shake to give some energy on the trails like Hammer Perpetuem? I have 31 containers sitting in my kitchen right now".
I don't see why not. At 17 grams of carbs, 4.5 grams of protein, and 4.5 grams of fat/dry oz, it is in the ball park. Perpetuem has ~22 grams of carbs, ~3 grams of protein, and ~2 grams of fat/dry oz, by way of comparison. From my experience and what I have read, the Ensure is a little heavy on the fat and protein, and light on the carbs, for eating while on the move, but not enough to make a huge difference. Why not give it a try and let us know how it turns out? I, for one, would be very interested in your experience. The upside to using Ensure is that you get 13 more calories/dry oz, but slightly less carbs to help burn body fat. This should not be a big deal, IMO. It is also cheaper than Perpetuem if you get a store brand, like Walgreens.