What are the reasonable limitations for carrying a backpack during
strenuous mountain hiking for someone with osteoporosis? I am 5'2",
normal weight, 55 years old, well-conditioned (have been a runner and
triathlete prior to my diagnosis two years ago). The T score for
lumbar spine is -3.2. I can find little on this type of exercise since
most exercise prepscriptions presume women with osteoporosis are not
engaged in regular exercising.

Hello, hypatia-ga!

   You are not the first women diagnosed with low bone density despite
years of weight-bearing activity. My good friend, who has been an avid
runner, skier and all-around exerciser, was also very surprised to
learn that her bone density, at age 50, was like that of a
non-athletic, 75+ year-old women!!! What are we to do? I have been
exercising all my life, and am nearing 50 myself. I haven’t had a bone
scan, and I wonder what it would show!

  As you are well aware, we are not doctors here at Google, and it is
out of my league to tell you the actual exercise level you can safely
aspire to without risk. Thus, I must first start out with that
familiar phrase: “Check with your doctor before undertaking any
exercise program.”

 Now, with that said:

  “If you already have osteoporosis, you might wonder whether you
should exercise at all. The answer for most people is YES… “Keep in
mind, however, that exercise alone can't prevent or cure
osteoporosis.” Read “How Can Exercise Help Prevent Osteoporosis?” at
http://ag.arizona.edu/maricopa/fcs/bb/exercise.html

  Backpacking is one of the “advanced” exercises recommended for
“preventing” osteoporosis. See “Bone Building Activities for the
Prevention of Osteoporosis” at
http://ag.arizona.edu/maricopa/fcs/bb/bonebuildingactivities.PDF

  There is also evidence that exercise such as hiking can actually
cause bones to “gain mass, slowing the process of osteoporosis.” From
“The Economic Benefit of Trails.” The American Hiking Society at
http://www.americanhiking.org/news/pdfs/econ_ben.pdf

  According to the National Osteoporosis Foundation, “activities for
strengthening bones include dancing, hiking uphill and backpacking.”
“Keep in mind that individuals who already have osteoporosis need to
consult a physician or physical therapist prior to pursuing any of
these types of activities. These exercise recommendations should be
adapted to the individual's age, lifestyle, strength and agility.”
Read “Understanding Osteoporosis” at
http://www.pc.maricopa.edu/departments/dental/Preview/preview/docs/part1/answer6-1.htm

  That last sentence in the above reference, however….. “These
exercise recommendations should be adapted to the individual's age,
lifestyle, strength and agility.”…is another indication that you
really should ask your doctor if there are any limitations imposed on
the weight of the backpack you can carry. I think your doctor would be
the only one who could give you any kind of definitive answer, if
there is one.

  The article, “Senior Hikers Scale the Heights,” by Karen Berger at
http://gorp.away.com/gorp/features/seniors/hik_sen3.htm, includes the
following advice:
  “ Two-time AT-thru-hiker and retired physician Dr. Vernon Vernier
recommends a trip to the doctor as part of your pre-hike planning.
"Even if you're in good shape, you could have a hidden problem that
might be exacerbated by the stress of hiking," he says. Women, in
particular, should talk to their doctors about osteoporosis, which can
be a problem because falls the uneven footing of a trail can lead to
falls.” (One extra tip is to use ski or hiking poles, which can help
with balance on uneven ground)
  
  Don’t despair that despite years of exercising, your bones still
show low density. It is becoming increasingly apparent that although
weight-bearing exercise can help prevent osteoporosis, there are many
other factors that contribute to bone loss.

  “The risk for osteoporosis increases if too little bone is formed
during youth, or too much is lost later in life, or both. Size and
quality of bone may be genetically determined, but other factors also
influence bonehealth. A family history of osteoporosis or bone
fractures, a lifelong low-calcium diet, Caucasian or Asian heritage,
lack of exercise, low body weight relative to your height, smoking,
drinking excess alcohol, lack of menstruation, and taking certain
medications are all risk factors for osteoporosis”. Read “What is
Osteoporosis?” at http://ag.arizona.edu/maricopa/fcs/bb/osteoporosis.html

  It has even been shown that Eskimo women, whose lifestyle demands
constant exercise, have a high predisposition toward developing
osteoporosis. Despite ingesting high amounts of calcium from fish
bones, the proportion of fat and protein in their diet hinders calcium
absorption. Read “A Homeopathic Perspective on Osteoporosis,” by Dan
Ullman. excerpted from the “One Minute or So Healer” (1991) at
http://www.homeopathic.com/ailments/new/Osteo.htm

 Seems we women can’t win!!! 

 Nevertheless, I hope you can get the okay from your doctor to carry a
heavy backpack and enjoy a wonderful, mountain hike! That fresh
mountain air always seems to do wonders for your mind, doesn’t it? I
live at 7,000 feet, with the mountains right outside my door. It would
be hard for me to stay out of them, despite my unknown bone
density!!!!
 
 Enjoy life!

 umiat-ga

Google search strategy
+osteoporosis +backpacking  
 
Further reference:
National Osteoporosis Foundation at http://www.nof.org/

Thorough and helpful. By including brief quotes from many resources I
got the "story" and the footnotes from the researcher.