The Essential Role of Strength Training for Healthy Ageing

As we age, many changes happen to our body. Some of these changes are great (wisdom, maturity etc) while others are less desirable, like stiff or sore joints, weaker muscles, reduced mobility and increased risk of falls. Healthy ageing, physically, depends on the ability to maintain the capacity of multiple physiological systems. Of those, the musculoskeletal (MSK) system not only enables human ambulation but also serves as a major metabolic storage site (i.e. acts as a reservoir for calcium in bone as well as glucose in muscle). However, as an older person reaches their sixth decade of life, there is a progressive decline in bone mineral density (BMD) (~1–1.5% per year) and muscle mass (~1% per year) and strength (~2.5–3% per year),1, 2 which predisposes to the risk of osteoporosis and sarcopenia

Osteosarcopenia is a syndrome that describes the co-existence of osteoporosis and sarcopenia, two chronic musculoskeletal conditions associated with ageing. Osteoporosis is defined as a “systemic skeletal disease characterised by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture”. Sarcopenia describes the age-related loss of skeletal muscle mass, strength and function. The rate of the loss of bone density and the loss of muscle mass accelerates in our 5th decades, but changes will start to occur in our thirties, so this is not just an issue for the very old or frail. However, the loss of muscle mass, strength and function often co-exist in a frail subset of the elderly population, leading to significantly worsened outcomes than seen in either condition alone.

Around 1 in 2 women and 1 in 5 men over 50 years old will sustain an osteoporotic fracture throughout their remaining lifetime. This, married to the increased risk of falls associated with a loss of muscle mass, means that people with Osteosarcopenia are more likely to fall and more likely to fracture if they fall.

Factors that can lead to the onset of Osteosarcopenia include Mechanical, Biochemical/Endocrine, Genetic and Lifestyle factors. Treatments for osteosarcopenia include exercise, improved nutrition and pharmacotherapy. As Physiotherapists, we are mainly concerned with the mechanical and lifestyle factors of Osteosarcopenia. Specialist or medical assessment and treatment is often needed to deal with other causes. Both osteoporosis and sarcopenia can result from reduced physical activity observed in ageing (Daly, 2017), lending support to the role of mechanical loading in preserving the bone-muscle unit and reversing the effects of reduced exercise

Luckily, we can gain both muscle mass and bone density, even as we age. This is where a well planned strength programme is essential. Randomized controlled trials (RCTs) have demonstrated the efficacy of progressive resistance exercise to stimulate osteoblastogenesis and muscle protein synthesis, leading to improvements in bone microarchitecture, muscle mass, strength, and functional capacity in osteoporotic and sarcopenic older adults.

An increase in muscle mass leads to stretching of collagen fibres and periosteum, leading to stimulation of bone growth. Both osteoporosis and sarcopenia can result from reduced physical activity observed in ageing (Daly, 2017), lending support to the role of mechanical loading in preserving the bone-muscle unit. Exercise programmes are even effective for frailer adults, with a meta-analysis of elderly residents in long-term care demonstrating a 29% reduced risk of falls in those that underwent combined resistance and balance training programmes. Regular exercise also reduces bone loss, particularly at the femoral neck.

Nutritional approaches to osteosarcopenia focus on vitamin D, calcium and protein intake, which, again should be done in consultation with a trained Dietitian

If you are interested in a customised strength and conditioning programme tailored to your lifestyle needs or you are concerned about loss of muscle mass, contact one of our specialised physios at PMC Physiotherapy Dunboyne.

References:
Kirk B., Zanker J., and Duque G. (2020) Osteosarcopenia: epidemiology, diagnosis, and treatment—facts and numbers, Journal of Cachexia, Sarcopenia and Muscle, 11, 609–618. 10.1002/jcsm.12567.
Paintin J, Cooper C, Dennison E. Osteosarcopenia. Br J Hosp Med (Lond). 2018 May 2;79(5):253-258. doi: 10.12968/hmed.2018.79.5.253. PMID: 29727228; PMCID: PMC5963675.