Effects of Resistance Training on Bone Density

Osteoporosis is a common condition found in older adults characterized by low bone mineral density (BMD). These individuals are at increased risk of fractures, primarily of the hip, spine, and wrist. Osteoporosis is estimated to cause 1.5 million fractures annually in the United States in people aged 50 years and older. Research indicates that exercise, primarily resistance training, can prevent the occurrence of osteoporosis and even reverse its effects.

Bone remodeling is a continuous cycle throughout all phases of life. The resorption of old bone by osteoclasts is followed by the formation of new bone by osteoblasts. In the first three decades of life, this process occurs equally to maintain a steady state between bone resorption and bone formation. However, decreases in estrogen associated with menopause lead to increased bone resorption over formation, accelerating bone loss.¹

The good news is there is a way to prevent this natural and progressive cycle from depleting bone mineral content. Wolff’s law states that bone will adapt to the loads under which it is placed. Meaning, increasing load on a particular bone will cause that bone to remodel itself over time to become stronger and more resilient. Research has proven that resistance training can prevent the decline in BMD in premenopausal women and even increase BMD in individuals diagnosed with osteoporosis.

RESEARCH FIRE

Nelson et al completed a 1 year randomized controlled trial looking at the effects of high-intensity resistance training in postmenopausal women. The study found that women who performed resistance training twice a week gained an average of 1% in BMD of the femoral neck and lumbar spine whereas the control group lost 2.5% and 1.8% at these sites respectively. In addition, the women in the resistance training group maintained total body bone mineral content (TBBMC), whereas the women in the control group had a 1.2% decline in TBBMC.²

Lohman et al studied the effects of an 18-month resistance training program on regional and total bone mineral density (BMD) in premenopausal women. They found an increase in lumbar spine and femoral trochanter bone mineral density in the exercise group at both the 12-month and 18-month follow up compared to the control group. They did not find any change in total body bone mineral content in either group.³

Simkin et al studied the effects of dynamic loading exercises of the distal forearm in postmenopausal women diagnosed with osteoporosis. During the exercise period, the mean bone density for the exercise group increased by 3.8% and decreased by 1.9% in the control group. However, no significant change in the bone mineral content was found in either group over the period of the study.⁴

Menkes et al studied the effects of strength training in a group of untrained men with a mean age of 59. After 16 weeks of strength training, they found an increase in bone mineral density in the femoral neck and lumbar spine compared to the control group.⁵  

Pruitt et al studied the effects of weight training on bone mineral density in early postmenopausal women. Following a 9-month weight-training program, they found an increase in lumbar BMD in the exercise group compared to the control group.⁶ 

Most of these studies support the use of targeted resistance training to increase regional bone density at specific loading sites. The research indicates that resistance training may have clinical application as a prevention and treatment for osteoporosis in a wide range of individuals. Resistance training may aid in optimizing peak bone density in premenopausal woman and may aid in maintaining or increasing bone density in postmenopausal women. The frail elderly may also benefit from progressive resistance training to help preserve bone density.

If you or someone you know is struggling with maintaining healthy bone density, talk to your doctor about starting a resistance training program. A physical therapist or qualified fitness professional can help design a program to safely and effectively help you reach your goals. 

Questions? Leave a comment!

Written by Hannah Sweitzer, DPT, OCS, CSCS

References

1. Demontiero O, Vidal C, Duque G. Aging and bone loss: new insights for the clinician. Ther Adv Musculoskelet Dis. 2012;4(2):61-76. doi:10.1177/1759720X11430858
2. Miriam E. Nelson, , Maria A. Fiatarone, , Christina M. Morganti, , Isaiah Trice, & William J. Evans, (1994). Effects of High-Intensity Strength Training on Multiple Risk Factors For Osteoporotic Fractures. JAMA The Journal of the American Medical Association, 272 (24), 1909-1914.
3. Lohman T, Going S, Pamenter R, Hall M, Boyden T, Houtkooper L, Ritenbaugh C, Bare L, Hill A, Aickin M. Effects of resistance training on regional and total bone mineral density in premenopausal women: a randomized prospective study. J Bone Miner Res. 1995 Jul;10(7):1015-24. doi: 10.1002/jbmr.5650100705. PMID: 7484276.
4. Simkin A, Ayalon J, Leichter I. Increased trabecular bone density due to bone-loading exercises in postmenopausal osteoporotic women. Calcif Tissue Int. 1987 Feb;40(2):59-63. doi: 10.1007/BF02555706. PMID: 3105835.
5. Menkes A, Mazel S, Redmond RA, Koffler K, Libanati CR, Gundberg CM, Zizic TM, Hagberg JM, Pratley RE, Hurley BF. Strength training increases regional bone mineral density and bone remodeling in middle-aged and older men. J Appl Physiol (1985). 1993 May;74(5):2478-84. doi: 10.1152/jappl.1993.74.5.2478. PMID: 8335581.
6. Pruitt LA, Jackson RD, Bartels RL, Lehnhard HJ. Weight-training effects on bone mineral density in early postmenopausal women. J Bone Miner Res. 1992 Feb;7(2):179-85. doi: 10.1002/jbmr.5650070209. PMID: 1570762.
7. Gutin B, Kasper MJ. Can vigorous exercise play a role in osteoporosis prevention? A review. Osteoporos Int. 1992 Mar;2(2):55-69. doi: 10.1007/BF01623838. PMID: 1536981.
8. LAYNE, JENNIFER E.; NELSON, MIRIAM E. The effects of progressive resistance training on bone density: a review, Medicine & Science in Sports & Exercise: January 1999 – Volume 31 – Issue 1 – p 25-30