Like many in her age group, Sylvia McGregor, 97, of Sydney, Australia, deals with her share of ailments — in her case, arthritis, osteoporosis, hearing loss, macular degeneration, lung disease, hypothyroidism, chronic kidney disease, heart disease and two total knee replacements. But unlike most minors, she does intense strength training twice a week.
She believes that the exercises she has been doing for 12 years have allowed her to live independently. “I still live alone and take care of myself,” she says. “It wasn’t until I was in hospital last year that I was told I had to have a walker to walk home on my own. So I said, “That’s OK with me.”
McGregor is in one of the fastest growing age groups – the over 80s. By 2050, this “oldest old” group expected to triple in number to 447 million worldwide.
Their longevity reflects improved management of chronic health conditions, allowing older people to live longer even if they have serious health problems. But physical function declines with age, and many older people become unable to care for themselves – undermining the quality of those extra years and decades. “Maintaining independence is so important for people,” says public health scientist Rebecca A. Seguin-Fowler, director of the Healthy Lifestyles Program at the Texas A&M AgriLife Institute for Advancing Health Through Agriculture and of StrongPeople, which manages nutrition in the community and physical activity programs. “Even if they’re living in a retirement community and then maybe in assisted living, they still want to be able to do things on their own as much as possible.”
Exercise is the best recipe to preserve independence, researchers say. But what is the right dose – in terms of frequency, intensity and duration? What type of exercise is best? At what age should you start—and how late is too late?
There are too few studies of exercise among the elderly to offer definitive guidelines for this age group, says Erin Howden, a researcher and exercise physiologist at the Baker Heart and Diabetes Institute and co-author of a review of exercise in octogenarians in 2022 Annual Review of Medicine. But the evidence for the “younger, older” – people aged 60 to 75 – is enough to provide good, basic advice for anyone who wants to keep gardening at 97.
Independent living requires the ability to perform the activities of daily living – bathing or showering, dressing, getting in and out of bed or chair, walking, using the toilet, and eating. Doing these things requires four physical attributes: cardiorespiratory fitness (how well the cardiovascular system and respiratory system deliver oxygen during exercise); muscle strength and power; flexibility; and dynamic balance, meaning the ability to remain stable while moving.
Biological aging affects each of them. Cardiovascular fitness—the ability of the heart and blood vessels to deliver and use oxygen during exercise—declines in adulthood as our circulatory capacity declines. This decline accelerates significantly in late life. Over 70, cardiovascular fitness drops by more than 21 percent per decade—and that’s for healthy people. Prolonged inactivity and common chronic diseases such as heart failure, diabetes and obesity make the situation worse. It is common for octogenarians to have cardiovascular function so low that it plays a role in protecting them from carrying out basic activities such as vacuuming and cooking.
Dynamic balance, which is essential for walking, climbing stairs and avoiding falls, also declines, thanks to the deterioration of the musculoskeletal system and neurological function. And muscle mass declines by about 3 to 8 percent per decade after 30, with the decline accelerating after 60. This often reduces both muscle strength—the ability of muscles to exert force, allowing us to lift objects—and muscle strength, the ability to do work quickly that we need to climb stairs. The more sedentary you are, the faster this wear and tear can proceed. This muscle loss, known as sarcopenia, is why walking, one of the most popular forms of exercise, is not enough to keep us independent. “People think, ‘Oh, I’m walking,’ but walking isn’t going to help you build muscle,” says Seguin-Fowler.
Lifelong exercisers have the best chance of maintaining functional independence in old age. Over the years, they have built greater physical capacity—strength, range of motion, endurance, and balance—and improved organ function. But that’s not most Americans. In fact, in 2018, only about a quarter of Americans 18 and older met the federal government’s requirements exercise guidelines for adultsaccording to the Centers for Disease Control and Prevention.
These recommendations: at least 150 minutes per week of moderate-intensity aerobic activity (or 75 minutes of vigorous-intensity activity), along with muscle-strengthening exercises such as weightlifting or resistance band work — at least 8 to 12 repetitions of each exercise — at least two days a week. To this, adults 65 and older should add balance and flexibility training—think tai chi, pilates, or yoga—about three days a week.
If that prescription sounds daunting, Howden offers this perspective: any physical activity is better than nothing, and it’s never too late to start. And seniors should always push themselves to do more. “Whether you’re walking, cycling or whatever your activity is, keep increasing the amount of time you do it – and then one or two days a week try to do something that’s a little more intense,” says she.
There are many ways to check the aerobic exercise box. Ann analysis of 41 clinical trials involving the elderly with an average age of 67 found that many modes worked, including walking, running, dancing and other activities, at varying levels of intensity and duration. In general, the more often a person exercises, the greater the benefit.
The bottom line: A healthy but sedentary 67-year-old man who engages in aerobic exercise three times a week for 30 to 35 minutes per session, working at a moderate intensity for 16 to 20 weeks, can expect to improve his aerobic fitness by about 16 percent compared to people who did nothing.
Aerobic exercise earlier in life is better at preventing—and at a younger age even reversing—the normal, age-related hardening of the arteries that is a risk factor for hypertension and stroke. For example, a study of 10 healthy but sedentary people aged 65 and over who worked up to 200 weekly minutes of vigorous aerobic exercise for a year improved their cardiovascular fitness, but the training had no effect on their arterial stiffness. In contrast, a small study of adults aged 49 to 55 years found that cardiovascular fitness improved and cardiac stiffness decreased through a combination of high-, moderate-, and low-intensity aerobic exercise for 150 to 180 minutes per week for two years.
Howden, who led the second study, sees a clear takeaway: “Middle and late middle age is when we need to get serious about incorporating a structured exercise program into our daily lives.”
And the muscles? Two decades of research show that resistance training can prevent and even reverse weight loss muscle massstrength and power that people usually experience as they age. Here’s what works, according to an analysis of 25 studies involving people age 60 and older, with an average age of 70: Exercisers should have two sessions of weight training on a machine per week, with a training intensity of 70 to 79 percent of their “one-rep “max” — the maximum load they could lift completely if they only did it once. Each session includes two to three sets of each exercise and seven to nine repetitions per set.
Regarding fitness for the oldest, the first study of this group was clinical trial with 100 frail, elderly residents of a Boston nursing home. The average age is just over 87, and more than a third of participants are 90 or older. The majority – 83 percent – used a cane, walker or wheelchair; half had arthritis; many had lung disease, bone fractures, hypertension, cognitive impairment, or depression.
Individuals in the exercise group completed a regimen of high-intensity resistance training of the hip and knee muscles three days per week for 10 weeks. For each of the muscle groups, the resistance machines were set at 80 percent of the one-repetition maximum. The training is progressive, meaning that the load is increased with each workout if the individual can tolerate it. Sessions lasted 45 minutes and in each session the exerciser performed three sets of eight lifts for each muscle group.
By the end of the trial, the exercisers had significantly increased muscle strength and mobility in the hips and knees compared to the non-exercise group. Four participants no longer used walkers after training, but instead used a cane.
The lead researcher on this study was Maria A. Fiataron Singh, now a geriatrician at the University of Sydney. For older people, she says, strength training that helps with balance is the highest priority exercise because it makes other forms of activity possible. “Most people, including health professionals, still have the idea that the most important thing is to help people walk, but that’s only important if they can actually walk,” she says. “You have to have strength and balance first.” Fiataron Singh started the strength training program, where McGregor and her older peers press weights twice a week, and no one gets off easy. “We actually increase the weight every time we see someone when they’re first starting out,” says Singh. “At some point, their gains are less steep, but they’re still gaining muscle if you keep going up.” When she looks at McGregor’s muscle mass graph over time – “Hers is rock solid” – Fiatarone Singh sees inspiration. “When someone in their nineties sees that they’re getting stronger,” she says, “they’ll tell you how good it feels.”
10.1146/knowable-121422-2
Lola Butcher writes about health and health policy.
This article originally appeared in Knowable Magazine, an independent journalistic venture from Annual Reviews. Read the original here.