Beagles and Unintended Consequences

As our backpacking miles approach 500 miles per year and our ages continue to advance (I'm 71, Susan 66), things hurt. Each trip has it's moments of splendor, but the number of days to become trail hardened keeps increasing. Eventually we get to the point where few people pass us while we are hiking, though they do pass us after we have stopped for the day around five or six pm. At that point we are usually talking about food at the last trail town, food at the next, etc. But, a question we think about, but don't discuss much anymore, is: Are we using up a scarce resource, or toughening up and extending the life of our joints. Well, it turns out that question has been answered, by some physicians writing in the Journal of Sports Medicine in 1997. Kaiser Permanente has summarized that article and some related ones in: https://xnet.kp.org/permanentejournal/Fall00/Osteoarthritis.pdf The short answer is no, you are not wearing out your joints, or doing much to them at all, unless you have a prior joint injury. Then you have a much greater chance of developing osteoarthritis if you do strenuous activity such as running. The unintended consequences are, did I really want to know this badly enough to pay the price in beagles. It turned out that in the most significant study, they had eleven beagles running on a treadmill at 3 km per hour, 75 minutes a day, every day for ten years, wearing a jacket weighing 130% of their body weight. I can see a beagle enjoying getting out and running 75 minutes every day, even for ten years, but a pack at 130% of body weight?? Sticking © 2009 backpack45.com in here to foil blog bandits. I didn't want to know that badly. Whatever the answer, I would have kept backpacking till my body told me it was time to stop. Sacrificing beagles for heart disease advances, or breast cancer, ok, for predicting athlete's future performance, no. Take enough case histories over that same ten year period and the answer should be clear without use of beagles.