Osteoporosis and bone health / by Adam Lewinski

Characteristics of osteoporosis

Throughout Australia, the most prevalent disorder relating to bone health is osteoporosis. Osteoporosis is described as a skeletal condition characterised by thinning and weakening of bones in the human body. Specifically, bone densities of more than two and half standard deviations below the adult mean value. Factors that influence the occurrence of osteoporosis include a negative energy balance, inadequate intake of fruits and vegetables, low calcium, hormone levels, strength and genetic factors. In addition, after the age of 40 an individual may lose up to 0.5 per cent of bone mass each year (McNeely, 2010). This in turn, causes an increased risk of developing fractures or breaks from bumps or falls, which particularly affects Australians in their latter years of life. Bone strength and the risk of fractures are determined by the structure and quality of the bone itself, not only the quantity (how much bone there is), where typical bones (or groups of bones) that are affected by osteoporosis are the wrists, pelvis, spine, shoulders and ribs (Kato, 2012). 

Disability from osteoporosis can be long or short term. Fractures can severely affect an individual’s ability to function and participate in activities of daily living, even long after the damage has healed. In serious cases, osteoporosis can render individuals bed-ridden. This may lead to not only physiological issues, but psychologically problems as well, where functional limitations can lead to social isolation and decreased interaction, employment and personal relationships (Australian Institute of Health [AIH], 2010).

Current health status and the prevalence of osteoporosis in Australia

The national health survey conducted between 2007 and 2008 found that approximately 700,000 Australians, almost three per cent of the population, had been diagnosed with osteoporosis. Specifically, the survey found that those diagnosed were primarily above the age of 55, in which 82 per cent were female. Unfortunately, cases of osteoporosis can often go undiagnosed as the condition has no symptoms and is typically identified after a fracture has occurred. This has led health experts to believe that the figures stated previously can be seen as an underestimation of the true prevalence of the condition in Australia. In addition, fractures of the hip contributed to more than 1,400 recorded deaths and 82,000 hospitalisations between 2007 and 2008 (AIH, 2010).

Nutrition and osteoporosis

Bones are dynamic organs composed of minerals (primarily phosphorous and calcium), organised into structures (or matrix) of collagenous and non-collagenous proteins. Where bone is constantly turning over minerals in a process called remodelling (destruction and reforming of bone by osteoclasts and osteoblasts respectively) (Lewis and Modlesky, 1998). Nutrition and physical activity through strength and resistance training play and integral part in maintaining bone health throughout life in everyday Australians. Inadequate intake of vital nutrients contributes to excessive bone loss and in turn, increasing the risk of developing osteoporosis. The maintenance and formation of bone with in the human body requires a constant supply of rich vitamins and minerals, which include but not limited to calcium, protein, potassium, magnesium and vitamin D (Palacios, 2006). 

Proteins are the building blocks of the body and allow the development of bone and collagen structures (matrix) with in the skeletal system. Protein also is vitally important in the production of hormones and other growth triggers that regulate bone synthesis. Calcium is one of the major minerals in the body, where 99 per cent of the body’s calcium stores can be found with in bones. Adequate calcium intake maximises peak bone mass and assists in preventing bone depletion in the latter stages of life. A diet rich in potassium encourages the development of an alkaline friendly environment in the body. This in turn reduces the demand for skeletal salts to be excreted from bone stores (which reduce acidity from foods), thereby preserving minerals with in the skeleton and play a part in reducing the risk of developing osteoporosis. Sixty per cent of the total magnesium in the human body can be found in bone. Magnesium indirectly affects mineral metabolism through its role in adenosine triphosphate metabolism. Further, magnesium directly affects bone quality by decreasing hydroxyapatite (a naturally occurring mineral form of calcium) crystal size. Meaning, reducing the development of large, perfect mineral crystals that result in brittle bone. Vitamin D is another essential nutrient that allows optimal development of bones by maintaining calcium absorption efficiency (Palacios, 2006). 

To maintain adequate intake of these nutrients and many more, the National Health and Medical Research Council suggests Australian individuals enjoy a wide variety of nutritious foods, focusing on cereals and whole-grains, plenty of fruits and vegetables, lean meats, poultry, fish, low-fat dairy and water. Additionally, limiting intake of saturated fats and consuming only moderate amounts of food containing excess sugar and salts (NHMRC, 2003). For example, excess dietary intake of sodium (and protein for that matter) can cause increased levels of calcium secretion, particularly in woman, as reported by Lewis and Modlesky (1998),

Physical activity and osteoporosis

Resistance and strength training is widely recognised as a fundamental type of activity, which can be included in exercise programs to improve bone mass (mineral density). This type of activity is characterised by utilising weights or resistance to increase mechanical stresses placed on the musculoskeletal systems of the body (Gómez-Cabello, Ara, González-Agüero, Casajús and Vicente-Rodríguez, 2012). In addition, strength training also targets the surrounding musculature, where Mansfield (2006) states that bones strengthen when the muscles attached to them become stronger, causing increases in bone mineral density (BMD) and bone remodelling as a result of targeted and purposeful resistance training and Therefore, preventing or reversing an average of one per cent bone mineral loss per year (Wolfe, Van Croonenborg, Kemper, Kostense and Twisk, 1999). Kato (2012) further support these arguments, by similarly stating that when applying a load greater than that which a musculoskeletal system is accustomed to, bone formation and structural adaptation results.

A study of BMD in postmenopausal woman by Bocalini, Jorge Serra, dos Santos, Murad and Ferreira, (2009) over a 24-week period discovered that strength training preserves and significantly increases BMD. Similarly, a 16 week study on whether strength training increases regional bone density and bone remodelling in middle–aged and older men by Menkes, Mazel, Redmond, Koffler, Libanati, Gunberg, Zizic, Hagberg, Prately and Hurley (1993), also demonstrated increases in BMD in areas such as the neck and the lumber spine, leading to conclude that bone-related characteristics can be enhanced through specific, weight or resistance training programs. 

To achieve increases in bone rigidity in most adults, loading of the musculoskeletal system through the use of high forces is necessary to initiate a physiological adaptation. Exercise routines with high load (80 per cent 1RM) and low (up to eight) repetitions, two to three times per week appear to yield the best result. With adequate rest periods, up to two precent increase in BMD can be seen over a six-month period. The amount of sets required is difficult to define, but what it most commonly accepted is that the muscular systems are required to be trained to failure to achieve any significant improvements (Wolfe et al., 1999). 

Training principals for bone health

When prescribing strength training programs, fitness professionals should focus on teaching proper technique first. By doing this, exercise professionals allow the client to feel safe, building the confidence and preventing the chance of injury when attempting heavier loads later on in the program. After which, fitness experts should prescribe as few as four strength-based exercises, which included five to six repetitions with a light load, characterised by the four primal movements which include a push, pull, leg (a squat variation) and a core exercise. As the client progresses, a positive increase in load is required to maintain development of muscle and bone strength. Additionally, high-impact (such as jumping) and balance exercises may also be included. This can further build confidence in clients as they can perform most of these exercises without supervision and was shown in a study of woman under 30 who performed 50 vertical jumps in addition to their regular exercise program experienced a BMD increase between two and five per cent over a controlled group that excluded such exercises (Mansfield, 2006). Similarly, McNeely (2010) also advises jump training should be included into any strength-training program. Stating that the inclusion of 50 vertical jumps on most days of the week was beneficial, particularly to woman pre-menopause (although interesting to note, studies shown that vertical jumps are not as affective on post-menopausal woman). In summary, strength-training programs that have shown beneficial results on BMD are characterised by training above 70 per cent 1RM for a period of 12 months with a training frequency of two to three times per week.

Considerations when prescribing bone enhancing programs

There are a number of exercise considerations that should be taken into account by fitness professionals when prescribing strength or resistance-based exercise programs. They may include, but not limited to the use of dynamic movements, exercise variation, intensity, frequency and duration. Osteogenic effects from mechanical loading generally only occur when exercises are dynamic and variable. Rapid changes or direction, impacts and explosive strength training can be particularly effective and should make up the build of any bone training program. Those suffering with advanced osteoporosis should phase in explosive movements gradually as their condition improves (McNeely, 2010). 

Bone adaptation occurs primarily at the insertion and origin points of muscles, suggesting that loads should placed on muscles that are responsible for prime movements (Ryan, Treuth, Rubin, Miller, Nicklas, Landis, Pratley, Libanati, Gundberg, and Hurley, 1994). A wide variety of exercise will ensure that bones receive a wide range of stimulus, further promoting increases in BMD. There is a linear relationship between improvements in bone density and weights lifted. As stated above, the minimal amount of intensity required to solicit bone adaptation is 70 per cent 1RM. Similarly, Chilibeck, Sale and Webber (1995) advise that explosive lifting with 60 per cent 1RM can yield results, only if the load progressively increases as that individual becomes stronger. Frequency and duration are also important factors. BMD changes can be seen in short training sessions only if the activities performed are high impact or load intensive, but the key is to perform these sessions frequently and at least three times per week. As mentioned previously, human bones undergo change based on the forces applied to them and can experience adaptation to both training and detraining, so consistency is can be seen as the key to improving BMD long term. Six to eight months is approximately the length of time bone needs to adapt due to it’s remodelling cycle, therefore this is the minimum time consistent strength or resistance training is needed for BMD to change significantly and in turn, yield long term results (McNeely, 2010).

Research has shown that prevention of osteoporosis and the development and maintenance of healthy bones stems from early intervention and the inclusion of physical activity and sound nutrition throughout life. Educating the general population about the benefits of resistance and strength training, the importance of nutrition, primarily in relation to vitamin D and calcium can also assist in reducing the number of Australians who develop skeletal conditions. It is up to fitness and health professionals to encourage the general population to think of exercising and nutrition as something that benefits individuals more than just aesthetically, but is the key to living a long and healthy life, free of debilitating conditions and maximising functional capacity right until the very end.

– Adam ‘Adrock’ Lewinski

Adam Lewinski is a qualified and professional strength and weight loss specialist. Adam Lewinski seeks to help busy, Sydney CBD-based professionals understand the benefits of physical activity and nutrition, allowing them to boost their health fitness, avoid the development of lifestyle diseases and live life to its maximum potential.

Contact Adam for a complimentary initial consultation and two 30 minute personal training sessions to discuss how you can improve your health and fitness now.

M: 0415044456 | E: adamvisionpt@gmail.com W: www.adrockpt.com

Reference list

  • Australian Institute of Health. (2010). Australia’s Health 2010. Canberra, ACT: Australian Institute of Health and Welfare.
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  • Gómez-Cabello, A., Ara, I., González-Agüero, A., Casajús, J.A., & Vicente-Rodríguez, G. (2012). Effects of training on bone mass in older adults: A systematic review. Sports Medicine, 42(4), 301-325.
  • Kato, T. (2012). Exercise for life-long bone health. Advances in Exercise and Sports Physiology, 17(3), 99-103.
  • Lewis, R.D., & Modlesky, C.M. (1998). Nutrition, physical activity, and bone health in women. International Journal of Sport Nutrition, 8(3), 250-284.
  • Mansfield, E.M. (2006). Designing exercise programs to lower fracture risk in mature woman. Strength & Conditioning Journal, 28(1), 24–26.
  • McNeely, E. (2010). Training to improve bone density in adults. A review and recommendations. Sport Journal, 13(3).
  • National Health and Medical Research Council. (2003). Food for health – Dietary guidelines for children and adolescents. Retrieved September 28, 2012, available from http://www.nhmrc.gov.au/publications/synopses/dietsyn.htm
  • Palacios, C. (2006). The role of nutrients in bone health, from A to Z. Critical reviews in food science & nutrition, 46(8), 621-628.
  • Ryan, A., Treuth, M., Rubin, M., Miller, J., Nicklas, B., Landis, D., Pratley, R., Libanati, C., Gundberg, C., and Hurley, B. (1994). Effects of strength training on bone mineral density: hormonal and bone turnover relationships. Journal of Applied Physiology, 77(4), 1678-1684.
  • Wolfe, I., Van Croonenborg, J., Kemper, H., Kostense, p., & Twisk, J. (1999). The effect of exercise training programs on bone mass: A meta-analysis of published controlled trials in pre and postmenopausal woman. Osteoporosis International, 9(1), 1-12.