Seniors with weaker muscles appear to have a higher risk of developing Alzheimer's disease and mild cognitive impairment, as well as a more rapid rate of cognitive decline, according to researchers at Rush University Medical Center. "Our findings suggest that impaired muscle strength precedes the development of cognitive impairment in aging and may be an early clinical marker," said Patricia Boyle, PhD, a researcher in the Rush Alzheimer's Disease Center. "However, decreased strength may not be a true risk factor. Rather, loss of muscle strength may be the result of an underlying disease process that also leads to cognitive decline and clinical symptoms of Alzheimer's."
In addition to affecting cognitive functions, such as thinking, learning and memory, Alzheimer's is also associated with non-cognitive signs, such as impaired gait and other motor functions, depression and decreased grip strength. Dr. Boyle and her colleagues studied 970 older adults with the average age of 80 who did not have dementia at their initial evaluation involving 21 tests of cognitive function, neurologic exams and measurements of muscle strength in 11 muscle groups. During the follow-up period, which averaged 3.6 years after the initial assessment, each participant completed at least one additional evaluation. Over the study period, 14.2 percent of participants developed Alzheimer's disease. Individuals who ranked in the top 10 percent on muscle strength had about a 61 percent reduced risk of developing Alzheimer's disease compared with those in the bottom 10 percent. The researchers found a similar association between muscle strength and the risk of developing mild cognitive impairment, the earliest sign of Alzheimer's disease. That finding suggests that assessment of muscle strength may be a useful clinical tool for early identification of individuals at risk for cognitive problems, who might benefit most from medical or other interventions, Boyle said.
The study also reported that the course of cognitive decline was more rapid in individuals with weaker muscle strength. Individuals who were stronger at the beginning of the study experienced a slower rate of decline. According to Boyle, the basis for the association between muscle strength and cognitive decline is likely complex. Possibilities include damage to the energy-producing mitochondria in the body's cells, which may contribute to loss of both muscle strength and cognitive function or decreased strength could result from stroke or other disorders of the central nervous system that may unmask subclinical Alzheimer's disease.
In addition to the possible link between cognitive function and strength, a lack of muscle strength impacts mobility and other types of function. That means that you will have a harder time doing everyday things, from getting up and down from a chair or bed to opening a jar.
According to the National Institute on Aging, even very small changes in muscle strengthâ€”muscle increases that may not even be visible in the mirrorâ€”can make a real difference in function, especially in people who have already lost a lot of muscle. Lower-body strength exercises in particular also will improve your balance, which helps prevent falling and its serious consequences.
Strength exercises generally involve lifting or pushing weightsâ€”light weights like dumbbells, stretchy resistance bands or even common objects from your kitchen like cans of soup. Advantage to joining a fitness center or gym over working out at home is having the help of a fitness trainer and a virtually unlimited amount of weights or other equipment that you can use as you gain strengthâ€”though you might start out with as little as one-pound weights, you want to gradually increase the amount of weight you use as you progress.
The goal is to do strength exercises for all of your major muscle groups on 2 or more days per week for 30-minute sessions each. Don't exercise the same muscle group on any 2 days in a rowâ€”muscles need the time off to recover from weight training, but you can still walk or do any type of cardiovascular exercise any day, including a strength-training day.
Here are other tips on strength training for seniors from the National Institute on Aging:
You don't have to buy weights for strength exercises. All you need is something you can hold on to easily (for some exercises, you will need two equal "somethings"). You may be able to make your own weights from unbreakable household items:
Another option is to use resistance bands, stretchy elastic bands that come in several strengths, from light to heavy. To perform exercises with a resistance band, you wrap one end around each hand and then follow the specific directions.
Get started with this simple strength exercise to improve your gripâ€”picking up and holding onto objects and opening jars.
Hold a tennis ball or a small rubber or foam ball in one hand. Slowly squeeze the ball as hard as you can and hold it for 3 to 5 seconds. Relax the squeeze slowly. Repeat 10 to 15 times, then repeat the same number of times with your other hand. Repeat the entire sequence one more time.