"why zebras don't get ulcers" rant

Why Zebras Don’t Get Ulcers by Robert Sapolsky is about how prolonged stress affects human physiology. The catchy title foreshadows how short bouts of stress, like the interaction between a zebra and a lion, don’t have the seemingly catastrophic physiological effects that Californians undergo by going to work everyday with their cup of coffee in hand. Sapolsky oversimplifies how zebras and lions relate to humans and stress, however the book does do a good job of explaining difficult physiological concepts without getting hung up on jargon. I enjoyed the book, twice over.
Once particular section sparked my interest. Sapolsky discussed how running more than 40 to 50 miles per week in thirty-year-old athletes may lead to decreased bone mass, increase risk of stress fractures and scoliosis; “their skeletons look like those of seventy-year-olds”. I have run more than 50 miles per week for several years now, and this is something I haven’t heard about. I was concerned; did I miss this in my graduate program in exercise physiology and biomechanics? After reading the articles Sapolsky referenced to support these arguments in the book, I wasn’t convinced. I did some research of my own, and I was confident that my running would not lead to low bone mineral density. In fact, current research shows that the biggest determinant in late stage low bone mineral density or osteoporosis is what levels of bone density you reached as a child (maybe by running). I wouldn’t advocate that a teenager be running more than 50 miles per week, however I don’t think it’s going to make them look like a seventy-year-old when their in their thirties either. I did find however that Sapolsky was right about having decreased testosterone after running greater than 40 miles per week. Maybe I’m more in touch with my female side than a runner with less weekly mileage, that’s okay with me.
I did enjoy the book, but I found that Sapolsky sometimes oversimplified or made leaps of faith from the literature. The holes in his logic for example: humans live much longer than zebras (70 in developed countries and 20 for a zebra), zebras are a type of horse (not the most evolved creature) while humans are arguably the most advanced creature on the planet, and finally without stress (assuming that the “allostatic balance” is the same for everyone) everyone would pretty much be the same. I like my cup of coffee. I like to stress my body and grow stronger. As a physical therapist I will stress people to make them better. A spoonful of stress does a body good.