The Importance of High Intensity Resistance Training in Menopausal & Postmenopausal Women with Osteoporosis

_{Osteoporosis is a progressive bone disorder characterised by loss of bone mass and strength which significantly increases the risk of fractures in the body (Sozen et al., 2017). This condition is most prevalent among women especially, during and after menopause as a result of the hormonal changes that occur during this stage of life (De Villiers, 2023). Osteoporosis is a major public health concern due to the increasing number of resulting fractures and its consequential impact on the quality of life. Recommendations for preventative measures issued by the National Osteoporosis Foundation attempt to address the risk factors associated with osteoporosis and advise to implement lifestyle changes such as reducing or eliminating smoking and alcohol intake, dietary changes to support calcium deficiencies and engaging in weight-bearing exercises (De Villiers, 2023). This article shall provide information concerning osteoporosis and explore the influence that high intensity resistance training (HIRT) can have on bone health. Additionally, it shall address the effects and the potential role this type of exercise could have on reducing fracture risk particularly in meno/postmenopausal women.}

 

_{Bone Remodelling & Osteoporosis}

_{Throughout life, from birth to adulthood, bone structure undergoes a continuous process of remodelling reaching its peak density at puberty and persisting throughout adult life (Otero et al., 2017). Remodelling, also known as bone turnover, involves the removal of old, vulnerable bone and replacing it with a stronger, healthier version which is essential in safeguarding and preserving its structure (Sozen et al., 2017).  Additionally, this process ensures integrity of bone structure by preventing naturally occurring microfractures from becoming problematic macro fractures (De Villiers, 2023). For optimum bone health, the rate of remodelling must be in dynamic equilibrium, with bone resorption and formation occurring at a similar rate. In osteoporosis, this balance is disrupted, and it is shifted towards a higher rate of resorption resulting in the net loss of bone mass and compromising its strength and architecture (De Villiers, 2023; Sozen et al., 2017). Statistical data demonstrates that 22 million women in Europe alone are affected by this condition. Furthermore, 30% of women worldwide sustain a fracture, 40% of which are a consequence of osteoporosis. Moreover, over the age of fifty, the risk of fractures increases by 14.6% in women and 3.5% in men (Daly et al., 2019; De Villiers, 2023).}

_{Menopause & its Influence on Bone Health}

Menopause is the stage in a woman’s life during which reproductive capability ceases. These physiological changes occur between 45 and 55 years of age and typically last up to one year after the last cycle (National Institute of Arthritis and Musculoskeletal and Skin Diseases, 2023). Common symptoms associated with menopause include hot flashes, mood swings, depression, brain fog and bodily aches (De Villiers, 2023). This period is defined by the last menstrual cycle and is characterised by a significant drop in Oestrogen levels which is one of the female reproductive hormones and the one mainly concerned with maintaining bone density and overall health (De Villiers, 2023). Bone mineral density (BMD) is used to objectively measure bone health and strength in women over the age of 50. It is expressed as a T-score that ranges between -1 and -2.5; a score below -2.5 indicates severe depletion in bone density and consequently an increased risk of fracture (National Institute of Arthritis and Musculoskeletal and Skin Diseases, 2023; Sozen et al., 2017).

Resistance Training

Over the years, there has been a significant amount of research that supports HIRT as an effective treatment strategy for osteoporosis (Benedetti et al., 2018; Daly et al., 2019; Manaye et al., 2023; Mcgrath et al., 2017; Otero et al., 2017; Wilhelm et al., 2012). While exercise in general is widely recognised for its benefits in improving overall fitness, strength and psychological and cognitive function as opposed to a sedentary lifestyle, resistance training can provide specific advantages for bone health. This is achieved through strong muscular contractions during multi-joint movements which indirectly provide a significant mechanical stimulus that supports bone turnover, maintaining and improving BMD (Benedetti et al., 2018; Daly et al., 2019).

Low impact and mildly strenuous weightbearing exercises such as walking have a questionable effect on BMD as the mechanical stimulus might not be significant enough to benefit from its effect on bone health (Benedetti et al., 2018).  Nevertheless, it is a widely accepted and safe activity that can at least, prevent from further rapid bone loss (Li et al., 2009). Other low impact exercises such as jogging and weighted stair climbing were found to preserve both the hips and spinal density (Benedetti et al., 2018). Muscle strengthening and loaded anti-gravitational activities enhance ground reaction forces that challenge the skeletal system and further encourage bone remodelling (Daly et al., 2019; Manaye et al., 2023; Mcgrath et al., 2017; Watson et al., 2017). While research suggests that increasing bone size may be difficult to achieve with increasing age, any weightbearing and loading exercises facilitate preservation of BMD and its microarchitecture (Benedetti et al., 2018; Manaye et al., 2023).

The consensus among research studies pertaining to strength training for menopausal and postmenopausal women with osteoporosis is that an effective strength programme must target all segments of the body and must apply incremental high loads with few repetitions (Daly et al., 2019; Manaye et al., 2023; Watson et al., 2017). Previous animal studies have demonstrated that bone responds best to dynamically intermittent loads that occur under high magnitude and speed, in fewer and diverse patterns of loading (Daly et al., 2019) This phenomenon aligns with the principle of exercise adaptation which suggests that frequent and repetitive cycles can cause bone to desensitise and adapt to the stimulus which in turn, decreases its ability to progress (Daly et al., 2019). Additionally, compound movements such as squats, deadlifts and bench press have been found to be more effective in improving BMD rather than isolating specific muscle groups (Manaye et al., 2023; Watson et al., 2017). Furthermore, high velocity resistance training, which is the ability to produce force quickly, has been found to have better results than traditional resistance training. Facilitates the preservation of type II fast twitch muscle fibres which tend to quickly deteriorate with increasing age (Manaye et al., 2023; Watson et al., 2017).

Despite the safety concerns associated with HIRT in women with low bone mass, research suggests that such programs can be safe and beneficial (Manaye et al., 2023; Watson et al., 2017). In the study conducted by Watson et al. (2017) demonstrated that post-menopausal women with a foundational level of strength, suffered no adverse effects throughout a supervised 8-month long resistance training regime. Furthermore, increasing neuromuscular strength in turn facilitates fall prevention and reduces fracture risk. Whilst there is a variety of suggested frequencies and session durations documented in research, a consistent regime that is done for a minimum 8-12-month period is required to note modest improvements in BMD (Benedetti et al., 2018; Daly et al., 2019; Watson et al., 2017).

Summary

Osteoporosis is a condition that greatly affects menopausal and post-menopausal women as result of the physiological and hormonal changes associated with this stage of life. As a non-pharmacological form of intervention exercise, particularly high intensity and high impact resistance training has shown to have a beneficial effect on bone turnover and bone health. A strength programme that focuses on full body and progressive overload training with heavy loads and fewer repetitions, potentiates an osteogenic effect on bone. Despite the safety concerns with such a training regime, research has shown that when done correctly, with proper technique and gradual progressions, HIRT is well tolerated among women. It is essential that intensity is built slowly over time allowing for adequate adaptation to the load with regressions and modifications done as necessary. Furthermore, this type of training encourages increases in strength, balance and functionality which is crucial for reducing fracture risk and ensuring better quality of life in aging women. It is important to note that it is the healthcare provider’s responsibility to assess, provide and monitor an effective exercise regime.

Lastly, consistency is paramount for achieving results, and it is important to realise that improvement will not always be linear. Whilst an exercise regime is an effective form of intervention, it is most effective when combined with other strategies such as lifestyle changes, necessary supplementation and in some cases, pharmacological intervention. This integrated approach allows for a more holistic approach to the management of osteoporosis.

Written by our own Rise Physiotherapist, Nicole Busuttil.

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