It is well known that physiological and performance measures increase rapidly during childhood – and achieve a maximum between late adolescence and approximately age 40. After that functional capacity declines – at varying rates, depending on lifestyle and genetic characteristics.
Both age and gender affect muscular strength and muscular power. Men and women both attain their highest strength levels when muscle cross sectional area is at its greatest – usually between age 20 and 40.
After this maximum, strength starts to deteriorate;
- We lose concentric strength, slowly at first, accelerating with age.
- Capacity for power generation declines – faster than max strength.
- Arm strength decreases faster than leg strength.
- Loss of eccentric strength happens at a later age.
The metabolic effects of reduced muscle mass, caused by normal aging or decreased physical activity lead to a high prevalence of obesity, insulin resistance, type 2 diabetes, dyslipidaemia, and hypertension. It is believed that strength-based exercise training and subsequent increases in muscle mass may reduce multiple cardiovascular disease risk factors.
The well documented losses of muscular strength and muscle mass with age, known as sarcopenia, have important health consequences because they are associated with an increased susceptibility to disability among the elderly, an increased risk of falls and hip fractures, a decrease in bone mineral density and an increase in glucose intolerance.
Sarcopenia:
Strength training can prevent the decline in skeletal muscle mass and function when daily living tasks are not sufficient to offset these declines with aging. Adults who do not perform regular strength training lose approximately 0.46 kg of muscle per year from after age 50. Furthermore, adults who do not perform strength training experience a 50% reduction in type 2 muscle fibres, the fibres responsible for high levels of strength, by age 80 years. The profound beneficial effects on the musculoskeletal system can contribute to the maintenance of functional abilities and prevent sarcopenia.
Osteoporosis:
Osteoporosis – the loss of bone mineral density, is one of the most prevalent conditions in postmenopausal women and the prevalence of osteoporosis also increases with age in men, though it is a greater public health concern in women. The morbid events associated with osteoporosis are fractures that primarily occur in the neck of the femur, the vertebrae and the forearm in older men and women. The loss of bone mineral density after menopause in women results in a doubling of hip fracture risk for every 5 years of age past the age of 50 years. In women ages 50-70, it has been shown that strength training maintained their bone mineral density, and those who participate in strength training have an enhanced density over their sedentary peers.
Osteoarthritis:
Osteoarthritis, the most common form of arthritis, is characterised by a progressive loss of articular cartilage around the affected joint leading to pain and functional disability. The prevalence of osteoarthritis increases with age and is seen most often in older women. Muscle atrophy and weakness have been hypothesised to contribute to the disability and pain of patients with osteoarthritis. Thus, strength training is thought to reduce functional instability and pain in older osteoarthritis patients by preventing sarcopenia and by improving the strength and function of the surrounding connective tissue, which is often damaged by the disease
Loss of Mobility:
The loss of joint range of motion (ROM) with age is well documented and is related to physical dysfunction and a decline in health status. This loss of range of motion may be associated with difficulty in climbing stairs, getting up from a chair or bed and the need for walking. Much of this loss is thought to be caused by inactivity, suggesting that increasing muscular activity might at least delay losses in mobility. Older adults who maintain high levels of muscular strength and mobility through resistance training with proper technique and ranges of motion are rarely candidates for long term healthcare.
Fall Prevention:
Cognitive impairment, visual deficits, environmental conditions and medication use, combined with physical activity related risk factors such as neuromuscular, gait and balance impairments increase the risk of falls. Nevertheless, strength training can improve strength, muscular power, walking mechanics and walking speed in the elderly, which can help to limit the risks of loss of balance or falls.
If you continue to strength train as you age, you will be able to maintain more of your functional capacity meaning you will maintain a quality of life and help to counteract some of the certain health deteriorations seen through aging.
Will Strathdee 
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