Originally Posted by
MoAlpha
My take is it looks pretty harmless and maybe good for a basically healthy back, but people with low bone density should be cautious about axial loads. Thoracic vertebrae, in particular, develop compression fractures with minimal, or, seemingly zero, trauma. Old former Cat I buddy of mine now has an ugly kyphosis and chronic discomfort from a couple of crunched ones.
I had similar thoughts to some of those being expressed in this thread about strength training, specifically barbell squats, and I think those concerns also translate into the realm of any sort of spinal loading.
I had gotten quite out of shape one winter many years ago and took my first Alpine ski of the year with a French friend who'd toured with the Dynastar demo team. While doing some particularly strenuous carving on hard snow, I felt and actually heard something give way in my back. I went to my doctor who ordered an MRI. The MRI reader of course missed the soft tissue injuries, but noted my lumbar stenosis, thin discs, and arthritic facets. I got the message that I was an out-of-shape older guy all right. I decided that I had to get serious with the strength training and did so. Though I had the concerns expressed above, I went ahead and experimented on myself doing hard and heavy back work. That was probably 20 years ago.
Today, my back is pretty much bombproof. I have osteopenia, here and there, but not in my spine. My discs haven't gotten any thinner. I had a bout of sciatica a few years ago. Stretching and heavy weight training made it go away and it hasn't been back. My wife and I go in with 40 and 60 lbs. respectively for our annual 10-day backpack. Our backs are fine with it.
Boiled down, I'm saying use it or lose it. If you have low bone density, the thing is to work it. In my 40s, I once sustained a compression fracture in a vertebra. I was carrying a 120 lb. long wet oak 2 X 12 by myself when I felt it go. So don't do that. but heck yes, carry a pack, load up your spine in the gym, work your back muscles as much as you can. They're what hold your spine in column. Start with moderate loads and work up to heavier ones over a period of a couple years. It's slow, but preventative exercise is a really good idea.
It's very, common for cyclists who do a lot of miles to have osteoporotic spines by the time they're 30. My mom essentially died from spinal compression fractures as her spine was badly osteoporotic. For exercise, she did water aerobics. Hard to think of a worse idea, though road cycling is right up there.
If you're worried about spinal bone density, go get a Dexa scan of your back - and femoral neck while you're at it. Then do something about it, whether you have that issue or not. One fall can change your life.
When I go out for local walks, I focus on pushing the pace. I think that's preferable in terms or body development to walking much more slowly with a pack. You want to get good at hiking with a pack, go the the gym with a backpack and hit the Stepmill for an hour. Stairway to hell, I call it. It's only boring until it starts to hurt. That, and fast walking or running without a pack will fix you right up.