What is the rate of  strength decline with ageing?

One consequence of ageing is a decline in strength, particularly in leg and arm muscles. Strength refers to how much force your muscles can produce when they contract. Thus, when an we move from a sitting to standing position, our legs must be strong enough to contract and lift our body’s weight. Most daily tasks require moving — and contracting — our muscles while exerting strength.

Muscle power refers to the strength of the muscle and how quickly the muscle can contract and move the body. Thus, muscle power is the product of both the maximal strength and maximal speed of a muscle.  Muscle power is very important in predicting how successful older adults are at performing daily activities independently such as climbing stairs and rising from a low chair. Moreover, when the power and strength declines in adults, it affects an individual’s ability to maintain balance, can lead to dangerous falls.

The decline in muscle strength and muscle power typically starts from about 50 years of age and increases more rapidly after 75 years in healthy older adults. And by the time an average healthy individual reaches 80 years, they maintain only half the strength and power of a 20- to 30-year-old person. In adults who do not regularly exercise, the decline in muscle strength and muscle power often begins a decade earlier (40 years of age). And the decline with age is even greater for inactive adults.

When an individual’s muscle power has decreased to a level when daily tasks cannot be easily performed, forms of assistance – such as the arm of a chair or even a walker – must be used. The concept of “moving effortlessly” is no longer viable, and a sense of independence with ageing can be compromised.

 

Why do we lose strength and power with ageing?

We lose strength and power as we age because we lose muscle mass. The medical term for decline in muscle strength, muscle mass, and physical function is sarcopenia. With ageing, the entire muscle becomes smaller because individual muscle fibers shrink in size, and some muscle fibers die. Additionally,  nerves that activate muscles also die. In general, muscle mass decreases approximately 3–8% per decade after the age of 30 and this rate of decline is even higher after the age of 60.   The percentage of lost muscle mass can vary in adults depending on an individual’s activity level.

loss of strength

Can you delay or even reverse age-related muscle decline?

The good news is that muscle loss with ageing can be postponed with regular strength training. Too, it is possible to rebuild muscle at any age. Research from the previous 30 years shows that improvements in muscle strength of older adults can be equivalent (as a percentage) to that of young people with a regular program of strength training. Studies I have conducted involving strength training legs of older adults demonstrate an increase in dynamic strength over 40% after 12 weeks of high resistance strength training.  Optimally, you want to build limb power and strength so that it is greater than the actual power needed to perform daily tasks.

 

How to maintain and build muscle strength and power

Even 80- and 90-year-olds can benefit from strength training. Consistent training sessions (two or three times per week) are critical to increasing muscle strength. And many standard exercises such as pushups, sit-ups, squats and lunges that utilize body weight as a form of resistance are effective at building strength and power. If you are new to fitness, exercises can be modified to adapt to your abilities.

If you need a starting place, download our SimpliMove App on your phone, tablet or desktop computer, where you can select up to 3 free exercise programs to build strength and power.

References

Fiatarone MA, Marks EC, Ryan ND, Meredith CN, Lipsitz LA & Evans WJ. (1990). High-intensity strength training in nonagenarians. Effects on skeletal muscle. JAMA 263, 3029-3034.

Fiatarone MA, O’Neill EF, Ryan ND, Clements KM, Solares GR, Nelson ME, Roberts SB, Kehayias JJ, Lipsitz LA & Evans WJ. (1994). Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med 330, 1769-1775.

Hunter, S. K., et al. (2016). “The aging neuromuscular system and motor performance.” Journal of Applied Physiology 121(4): 982-995.

Hunter SK, Thompson MW, Ruell PA, Harmer AR, Thom JM, Gwinn TH & Adams RD. (1999). Human skeletal sarcoplasmic reticulum Ca2+ uptake and muscle function with aging and strength training. J Appl Physiol 86, 1858-1865.