11 years ago, when I was only 62, I took my son in law on a 75 mile hike which lasted ten or eleven days. We were carrying 80+ pounds on our backs and travelling over very rugged terrain. We ate oatmeal, along with whatever we could shoot or catch (grouse, whitefish, grayling, trout). My son in law started out at about 250 pounds and weighed 205 at the end. I started at 185 and dropped twenty pounds. So this is the answer; burn more calories than you take in. A lot more. Those who remember basic training will recall how much weight some people (those who were carrying too much) lost during the process. A one hour gym session doesn't burn enough extra to accomplish anything. Walking for an hour does little. Walking uphill with a heavy pack for an hour uses some energy. My wife accuses me of doing things the hard way but doing that helps me to keep semi-fit; for my age. Embrace the exercise, I tell her. GD
