I prepared for this caribou hunt, knowing it would be hard. I increased the frequency and length of my early-morning walks with Quigley, my yellow Lab, on an up-and-down golf course near my Nebraska home. I sought out the rough edges and steepest hills. I added weight to my pack—10, 20, 30, and, finally, 40 pounds. I cut calories and lost weight. I called it my four-word diet: Exercise more, eat less.