by Fran Mason
Clearly explained bone density research
“Designing Exercise Programs to Lower Fracture Risk in Mature Women” by Elaine M. Mansfield, NSCA-CPT, Colgate University Wellness Program, is the clearest “plain English” article I’ve seen describing research into improving bone density and reducing fracture risk. As a CrossFit trainer, I’ve trained several clients who had been diagnosed with osteoporosis or osteopenia. Who knows how many more trainees have these conditions but don’t know it, or didn’t tell me.
Research findings and how I can help you implement them
In a nutshell, I can teach you to deadlift, squat, and carry heavy things, and I can choose weights and workouts for you that follow the recommendations in Mansfield’s review of the research.
Heavy, low-rep, single sets of lifts work well for the hip bones, and “weighted marching” (the article mentions a weighted vest or backpack) work well for the bone health of the whole body. (Sounds like the classic CrossFit workout “finisher”: a farmer walk with two kettlebells. Hurts so good!) These high-effort lifts improve bone density significantly more than walking, more than long runs and jogging, and more than lightweight, multi-set, high-rep lifts.
My low-bone-density women clients (often veterans of other health issues as well) are extremely motivated. Every time I have them do a basic barbell lift such as the deadlift, they keep adding weight to the bar as long as I’ll let them. This is appropriate, as long as they can maintain good form. Research shows that for women who are fit enough to tolerate it, working up to a single set of 8 squats or deadlifts at the 8-rep max or 80 percent of the 1-rep max three times a week can have a measurable impact over the long term. On the other hand, walking and running alone did not have the same effect. The “weight-bearing exercise” that mainstream health articles talk about turns out to mean not just bearing your own weight; you have to pick up something heavy. Luckily, this is really fun to do when you learn how.
Helping your bones doesn’t mean spending tons of time in the gym: maximal loading (heavy weight and high effort) is important, but frequency and duration of exercise sessions are not onerous. Women who did strength workouts three times a week, consisting of two heavy sets of 8 reps of about nine exercises, experienced good results. That researcher found it better to increase the effort put into a few sets than to add more sets or more exercises.
Starting to lift heavy is a process; what it feels like to lift heavy
If you work out with me, you’d use fewer than the nine exercises per workout mentioned above, at least until you had learned excellent technique one or two lifts at a time. This would still be a high effort workout and would make you tired in a different way from a “cardio” or conditioning workout. Pure strength efforts seem to make people sleepy, or a little spacy, or you just plain want to sit down. This hits an hour or so after the workout. (And I love it because I sleep SO well if I take a nap!) You might not be as sore the next day as you’d be from a conditioning workout. It’s a different kind of intensity. It takes a few months of experience to build up to that type of high effort or intensity.
From the Mansfield article: “High-load, low-repetition exercise routines with adequate recovery time build bone mineral density most effectively.” Maximal load, not maximal frequency. Rest between workout days. Two to three strength workouts a week is adequate. Rest between sets during the workout, too. If, like a lot of CrossFitters, you consider yourself a compulsive exerciser, focus your compulsion onto effort, not quantity.
Not everything is measurable by scan
I found this eye opening: “Exercise reshapes bone microstructure and geometry, increasing bone strength and decreasing fracture risk in ways not measurable by bone scan.” (Emphasis mine.) Exercise is good for your bones regardless what your next bone scan shows. You can be reducing your fracture risk dramatically, and building your bones significantly, even if the scan shows only a small improvement. The scan seems to be the tip of the iceberg, based on the research cited.
In some cases it can take a long time to see the results. “It can take 6 months or more for bone to remodel under the best conditions, and measurable effects of exercise may only be apparent years later.” Mansfield cites women who exercised for two years. Their back erector muscles gained significant strength, but BMD did not change during that time. Nevertheless, ten years later the exercise group had better spinal bone density than the control group and a much smaller relative risk of fracture. So, do your intense strength training for its own sake, and trust the result.
Finally, Mansfield seems to be channelling CrossFit when she writes: “Emphasize a full range of motion, especially when working the muscles along the back. The last few inches of a pulling motion [as in a deadlift] make all the difference in stimulating the muscles along the spine….” Full range of motion, that’s what we like too.
Excerpts used with permission of Elaine M. Mansfield. Please see the original for citations.