Older adults, particularly postmenopausal women, are often advised to pursue low-impact, low-intensity exercise as a way to preserve joint health, but that approach might actually contribute to a decline in bone mineral density, researchers report.
Concerns about falls and fracture risk have led many clinicians to advise against higher-impact activities, like jumping, but that is exactly the type of activity that improves bone density and physical function, said Belinda Beck, PhD, professor at the Griffith University School of Allied Health Sciences in Southport, Australia.
"There has always been a quandary in terms of pursuing research on this," she told Medscape Medical News. "We know from animal studies that bone only responds to high-intensity activity, but we worry about advising that for people with low bone mass, so instead we give them medications."
"But not everyone likes to go on meds, they're not 100% effective, and they're not free of side effects," said Beck, who is also the owner and director of The Bone Clinic in Brisbane, Australia.
In 2014, to assess whether high-intensity resistance and impact training (HiRIT) was a safe and effective way to improve bone mass, Beck and her colleagues conducted the LIFTMOR study of 101 postmenopausal women. The researchers showed that bone mineral density in the lumbar spine and femoral neck regions and functional performance measures were significantly better in the 49 participants randomized to HiRIT for 8 months than in the 52 randomized to low-intensity training.
Three years after the completion of LIFTMOR, the researchers looked at bone mineral density in 23 women from the HiRIT group in their retrospective observational study, the results of which were presented at the virtual American College of Sports Medicine 2020 Annual Meeting.
Ongoing gains were significantly better for the seven participants who continued with HiRIT (at least 25% compliance) than for the 16 who did not when looking at both bone mineral density of the lumbar spine (8.63% vs 2.18%; P = .042) and femoral neck (3.67% vs 2.85%; P = 0.14).
However, the women who discontinued HiRIT after 8 months maintained the gains in bone mineral density that they had achieved 3 years earlier.
Functional outcomes in the women who continued HiRIT were better than those in the women who did not, but the differences were not significant.
"The takeaway here is that this type of exercise appears to be a highly effective therapy to reduce risk of osteoporotic fracture, since it improves bone mass," Beck said.
Jump More, Lose Less Bone Density
Given the widespread reluctance to suggest HiRIT-type activity to those with low bone mass, this research is significant, said Vanessa Yingling, PhD, from the Department of Kinesiology at California State University, East Bay.
"Once women hit 60, they're somehow regarded as frail, but that becomes a self-fulfilling prophecy when we take this kinder, gentler approach to exercise," Yingling told Medscape Medical News. "Building bone density in older adults is important, but maintaining current bone density is just as crucial. Without high-impact activity, we are likely to see decelerating density at a faster rate."
The other key to the recent research is the functional testing, Yingling added. In addition to bone density measures, high-intensity activity can improve mobility and muscle strength, as the study noted.
This type of activity can be done in shorter bursts, making these workouts more efficient, she explained. For example, a Tabata high-intensity interval training session usually takes about 10 minutes, warm-up and cool-down included.
"A HiRIT workout even once or twice a week would likely improve function, strength, and bone density maintenance," Beck said. "The result of that would be better fall prevention and potentially less medication usage for BMD issues."
Both men and women can benefit from a HiRIT workout, Beck and Yingling said. Initially, supervision by a knowledgeable trainer or physical therapist is ideal, they added.
American College of Sports Medicine (ACSM) 2020 Annual Meeting.
Medscape Medical News © 2020
Cite this: High-Impact Training Can Build Bone in Older Women - Medscape - Jun 26, 2020.