Bone density is one of the primary factors involved in bone health, and it changes as the result of several stimuli, including activity level. One of the most deleterious and well-known factors in regards to bone density is age. With a high rate of bone breaks and fractures amongst the elderly and osteoporosis as a major symptom in postmenopausal women, bone density problems are common and alleviating them is a goal all people should strive for, ideally before the problem even starts.
Bone density is one of the primary factors involved in bone health, and it changes as the result of several stimuli, including activity level. One of the most deleterious and well-known factors in regards to bone density is age. With a high rate of bone breaks and fractures amongst the elderly and osteoporosis as a major symptom in postmenopausal women, bone density problems are common and alleviating them is a goal all people should strive for, ideally before the problem even starts.
Although studies indicate weight-bearing exercise helps improve bone density, we don’t know what kinds of weight-bearing exercises are the best. In a study this month in the Journal of Strength and Conditioning Research, researchers looked into which weight-bearing exercises had the most benefit against osteoporosis and osteopenia.
Osteoporosis and osteopenia are both characterized by low bone density. Osteopenia is when bone density begins to slip and is a warning factor for osteoporosis. Bones with low density are more likely to break, but bone density isn’t the whole picture. In fact, high bone density may also put individuals at greater risk for injury, although it is not as common and likely results from some other disorder.
Another factor of great importance in bone health is bone mineral content. The content of the bone, not just the density, affects how supple and strong a bone is. The bone mineral called hydroxylapatite is comprised mainly of calcium and phosphorus and can make up as much as half of the weight of your bones.
The creation of new bone, and how dense, strong, and well-rounded it is in content can be at least partially manipulated by our activities. In the study in question, researchers chose the squat as the activity to be tested. The researchers took a group of older women who were all in a state of osteopenia or osteoporosis and more or less told them to go big or go home. The women did heavy squats with less than five reps per set and performed the concentric portion as fast as possible. The researchers also had a control group that followed the current exercise guidelines for osteoporosis.
At the end of twelve weeks, with three squatting sessions per week for the training group, the researchers were ready to compare the post-training results with the pre-training bone tests they performed. The squatting was successful at making the women stronger, with a 154% improvement in one rep max and a 52% improvement in rate of force development. Along with greater strength came greater bone mineral content and enzymatic markers for bone growth that were not present in the control group. Although bone mineral density showed no significant improvement, it did improve slightly. In the control group, bone mineral density was slightly reduced.
Because both strength and bone health prevent injuries, and probably help our longevity as well, strength training seems to a necessary and integral part of our health. And although more research is needed to know its effects on bone density, strength training probably prevents bone loss as well, even in people with osteoporosis.
References:
1. Mats Mosti, et. al., “Maximal Strength Training in Postmenopausal Women With Osteoporosis or Osteopenia,” Journal of Strength and Conditioning Research, 27(10), 2013.
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