The New York Times article, “Exercise is Not the Path to Strong Bones,” by Gina Kolata, has certainly created an uproar. It’s a shocking title, especially for those of us working hard to keep up our bone density. One friend suggested perhaps it was an April Fool’s joke, and frankly, I had the same thought last night. My knee-jerk reaction is to always try to find the good in anything, but in my opinion, that wasn’t a well-thought-out article about exercise and strong bones. It addressed an important misconception, but then proceeded to be all over the place with inaccurate conclusions. In my opinion, it wasn’t helpful or good journalism.
To be helpful, it should have said, “Exercise is the Path to Build Bone in Youth and Maintain Bone Density and/or Slow Down Bone Loss After Age 30.” —Long, specific, but not nearly as attention grabbing.
My favorite NY Times author, Gretchen Reynolds, always carefully pours through the research and presents top-notch, helpful articles on exercise. For an example, see her story about the research of Dr. Janet Rubin, showing that exercise stimulates bone marrow stem cells to become bone cells instead of fat cells. “More Bone (and Less Fat) Through Exercise.”
Sound Research: Exercise Helps Bone Density
I wonder why Kolata paid no attention to the fact that astronauts now spend 2 hours a day doing cardio and strength training with a massive weight machine in space to maintain their strong bones.
—Or why she didn’t consult experts such as Beth Dawson-Hughes, director of the Bone Metabolism Lab at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University and a professor of medicine at Tufts.
When asked “Does exercise help bones?” Dr. Dawson-Hughes responded, “It’s hugely important—both aerobic and strength training.” –Nutrition Action Health Letter, December 2014
To be fair, the misconception listed in the NY Times article, “All you have to do is walk or do modest strength training exercises to build strong bones,” is indeed a misconception.
- Walking contributes to maintaining bone or slowing down bone loss (so keep it up!), but has never been shown to build bone.
- Modest strength training also doesn’t build bone, but research shows that higher intensity strength training can, by around 1%.
- Strength training needs to be more than modest—enough to challenge the bones—to get them to pay attention and activate osteoblasts, the bone-building cells, to maintain or slow down bone loss.
- IMPORTANT!—The problem is, scientists consider a 1% gain in bone density to be holding steady, not building, hence the suggestion that exercise doesn’t help build bones.
Building Bone Density, Maintaining, or Slowing Down the Loss: Depends on Your Age
It’s also curious to me that the NY Times article makes the blanket statement, “Exercise is Not the Path to Strong Bones.” It isn’t accurate for all age groups, in light of solid exercise research done through the decades.
- For young people, exercise is vital for building peak bone mass.
- Sedentary people lose bone mass.
- By age 30, peak bone mass has been achieved and it’s a matter of maintaining as much as you can for the rest of your life.
- Exercise gives your bones a reason to be strong. Without it, your body senses that it doesn’t need strong bones and the bone building cells, the osteoblasts, don’t keep up with the bone clearing out cells, the osteoclasts.
- Other factors besides exercise also influence bones, such as genetics, nutritional support, bone-depleting medications, alcohol and smoking. One’s best efforts with exercise may be no match for genetics or a medication that prevents calcium absorption. But it’s still important to fight back and keep exercising!
- Exercise, no matter what your age, is a very important part of the equation for bone health.
Positive Research Over the Decades: Gotta Work Hard Enough
Miriam Nelson, PhD, author of Strong Women Stay Young, wrote about the research that was done at Tufts University with strength training in the 1980s and 1990s. She talked about the study in which men in their sixties worked at half their capacity because it was feared that injuries or cardiac events would happen. She said, “These timid programs didn’t accomplish much—in strength training, feeble efforts produce puny results.”
Tufts scientists moved on to researching higher intensity strength training, around 80% of a person’s maximum and had tremendous results, even with nursing home residents with at least 2 chronic diseases. Dr. Nelson’s pioneering research from over 20 years ago showed that postmenopausal women could gain 1% bone density with strength training, while the control group that didn’t strength train, lost 2%.
Research shows that for those in their middle and older adult years, moderately-vigorous to vigorous exercise can contribute with these small gains or help maintain or slow down the loss of bone density that naturally comes with age. Exercise may not build bone back, but maintaining or slowing down that loss is a huge benefit.
Note: How hard a person with bone loss can exercise is best determined with one’s health care provider and a physical therapist.
I make my living with exercise. I have 2 DVDs on strength training that I sell on Amazon, and my day job is teaching women how to strength train. We have a blast together, we keep learning, we keep hope alive that we’ll make it to the end, independent and in fine form.
I’m one of the folks putting exercise advice from university research out there into the world and I need to keep my facts straight. At least half of the women in my classes have osteoporosis. Combing through exercise research is a constant in my life. For years, I made posters, brought handouts, and gave a running commentary during my class warm-ups, letting participants know about the latest university research on why strength training and weight-bearing cardio are fabulous for healthy bodies and strong bones, especially for those of us over fifty.
Now, I blog and send an online newsletter, instead of making those posters and handouts, but still give daily tips, backed up by research, to keep everyone motivated to move. *See the links below for some of that research.
I’m always on the lookout for great information, and this article wasn’t one of them. But it did give me a chance to emphasize these two points:
- Strength training at a modest intensity is not going to help. Working up to (safely and gradually) a moderately-challenging to challenging intensity, is needed in order to make a difference for our bones.
- The difference is not in building large amounts of bone, but maintaining what we have and slowing down age-related bone loss. Gains in the 1% range are so much better than continually losing bone. And those stronger muscles you build while exercising will help you stay agile, on your feet, with the necessary strength and balance to give you a better chance of breaking a fall, not a bone, if you do trip.
That exercise may also help bone quality is the next hopeful chapter being researched in keeping our bones strong. Results may not be definitive during our lifetimes, but keep up your exercise and stay tuned! And please send any good research reports my way. Thanks! –Susie
*Sampling of University Research Links:
Exercise May Reverse Age-Related Bone Loss in Middle-Aged Men:
Effect of Weighted Exercises on Bone Mineral Density in Post-Menopausal Women: A Systematic Review: