I feel the number one and most important action to loose weight is to eat right. Exercise helps, but, long term, to keep weight off, eating right for a life time does more good. You have to do a LOT of exercise to compensate for a piece of apple pie! People who depend too much on exercise fall off the wagon and gain weight back if they have to stop - say for illness, injury, other life events that tend to interfere with exercise. The best exercise is to incorporate more movement in everyday living. Less driving, more walking, less TV watching, more gardening, etc.

I think long backpack trips are VERY effective for weight loss. For one thing, you take a certain amount of food, a set limit of calories. No refrigerator to raid! I rarely am hungry backpacking, even when I am loosing weight.

Running is efficient if you are really short on time to devote to exercise. If you only had 20 minutes a day, then yes, you would get more from running. But if you can manage an hour a day then walking does about the same. You have to set a pace that works you - strolling along may not do much. Hills are the best. But for the long haul, walking for the rest or your life, because you like it and will stick with it is better than running, getting hurt, quitting. I actually think running when 40 pounds overweight would NOT be good. Walk, hike, backpack, do your SAR and eat right - get weight down, THEN maybe run. You may like it better when you are leaner.