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Even before the pandemic, Americans weren’t getting enough exercise, despite all the doctors, health organizations and government agencies encouraging us to get off the couch. The Department of Health and Human Services released its well-known 150-minutes-of-exercise-per-week guideline in 2008, while an American Heart Association handbook on exercise training dates all the way back to 1972. Still, chronic disease rates and health-care costs continue to rise.

Now that most of us are rethinking our exercise regimens, it’s a good time to consider a different — and possibly more effective — approach to increasing our level of activity. A study published in January argues that we should obsess less about that 150-minutes-a-week goal and focus instead on a greater variety of exercise. “It may be that the current guidelines place too much emphasis on frequency and volume of exercise,” said Susan Malone, first author of a paper published in the journal Translational Behavioral Medicine. “If we refocus people to more varieties of exercise, they might have more success reaching the targets.”

This conclusion arises from an analysis of the physical-activity patterns of more than 9,000 U.S. adults. Malone and colleagues from New York University’s Rory Myers College of Nursing dug deep into a U.S. database known as the National Health and Nutrition Examination Survey (NHANES). They looked for total minutes of exercise and the number of different activities pursued by the subjects.

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A full 44 percent of respondents reported that they did no physical exercise of any kind in the previous month. Among the respondents who did exercise, walking was the most popular exercise by far, practiced by 30 percent of respondents. It was followed by bicycling (9.5 percent), dance (7.5 percent), treadmill walking and running (7.4 percent), and weightlifting (6.9 percent). At the far end of the scale, two people engaged in gymnastics and surfing. The questionnaire picked up 47 different types of physical activity.

The global spread of covid-19 forced many people indoors for longer than they’d been used to, altering eating, cooking and exercise habits. (Video: The Washington Post, Photo: Graphic: Daron Taylor/The Washington Post)

The key finding: Subjects who did more types of exercise also accumulated more total exercise. In other words, although walking is good, it’s even better to mix walking with swimming, strength training and dancing, for example. Or with yoga, pickle ball and balance/core exercise sessions.

Three might be the magic number. Americans who do three or more different activities per month are more likely to achieve 150 minutes of exercise per week than those doing just one or two activities.

A separate sub-analysis yielded important results for women. Because of household responsibilities, women report having seven fewer hours of free time per week than men and are less likely than men to engage in exercise sessions that take an hour or more. Instead, women typically do 30 to 40 minutes at a time.

This sounds like bad news, but it doesn’t have to be. In fact, Malone and colleagues found a silver lining. Many women in the study reached 150 minutes a week because they exercised frequently — six days a week, on average. They were disciplined, consistent and ultimately successful in their exercise regimen.

“This is a great message for women,” Malone said. “We should emphasize that a program of frequent, short exercise sessions can work very well. They can do daily short walks, find gyms with short workout programs or even follow along with exercise videos at home.”

Even in the case of these successful female exercisers, the research supports doing more than one type of physical activity. In Malone’s study, those who did only walking were less likely to reach the 150-minute target than those who did several different types of activity.

Malone’s conclusion — seek more exercise variety — has long been propounded by personal trainers and public health advocates. As with many areas of lifestyle and personal health, we need more data to provide stronger evidence. Still, the advice passes the common-sense test.

Here are some of the main points often argued by trainers and exercise-health experts.

●The more types of exercise you do, the easier it is to stay motivated. “When you spice up your routine,” Malone said, “you increase the chances that you’ll enjoy the various activities and continue to practice them.”

●Adding variety with strength training pays off. Although cardio tends to get the most notice, given all the walkers, runners and bicyclists out there, the federal guidelines also recommend several resistance training (strength) sessions per week. This advice got a big boost from a recent analysis of 1.7 million American adults. It found that those who did both aerobic and strength training had the “lowest prevalence of obesity” — lower than those who did just cardio or just strength. Moreover, the most obese individuals had the most to gain from this combination tactic.

●Variety prevents overuse injuries. Most exercise injuries are caused by doing the same thing over and over again (runners’ knee, swimmers’ shoulder, tennis elbow). When you vary your exercises, you reduce your risk of injury.

●Variety benefits different body systems. Swimming and bicycling provide great cardio and some strength benefits, but they don’t do much for the bones (because they are non-weight-bearing). For bone health, add strength training or high-impact sports such as basketball. Yoga and gentle stretching may offer mental health benefits. Hiking in the natural environment can increase your general sense of well-being. Walking with Nordic ski poles can boost calorie burn by 18 to 67 percent over regular walking.

●Adding variety through more “social” exercise offers its own rewards (something to remember post-pandemic). One study showed that subjects who engaged in tennis or badminton had greater life expectancy (vs. non-exercisers) than swimmers or joggers. Another reported that those playing “team sports” had fewer days of bad mental health than those pursuing individual sports.

Although “variety” research among adults is fairly new, the principle has been studied more thoroughly among children and adolescents, who also benefit from the practice. Orthopedists Adam Tenforde and Michael Fredericson have spent decades investigating bone injuries in young athletes. They have concluded that sport specialization can have a negative effect, while ball sports and sports variety improve bone health.

In one paper, they found that youngsters who participated in “high impact and multidirectional sports, including soccer and basketball, consistently had greater bone mineral density and enhanced bone mineral geometric properties compared with those who participated in repetitive lower impact sports such as distance running.”

Early muscle development also serves as a springboard to lifetime exercise engagement. Years ago, kids got strong by frolicking on a jungle gym. Now they get weak by sitting on the sofa with their cellphones and video games.

“A compelling body of evidence indicates that resistance training for youth can be safe, effective, and worthwhile,” noted Avery Faigenbaum in an email. “These youth are more likely to be active later in life.” Faigenbaum, a professor of exercise science at the College of New Jersey, has written extensively on the subject.

Like many, Malone found her fitness routine upended by the coronavirus. To cope, she put into practice what she learned from her exercise-variety study. Primarily a pool swimmer for many years, she switched to the ocean off Sea Bright, N.J., when her pool closed. “It was chilly when I got started in May and has been quite an adventure on some of the rougher days,” she notes. “But I’m getting out there four to five times a week.”

Her 25-year-old daughter moved home from New York and talked Malone into a nearly forgotten activity. “We’re running/walking two or three times a week — an activity I had given up 10 years ago,” Malone says. The two are also taking online classes together, primarily barre and yoga.

Malone recognizes that even untraditional exercise activity counts toward a personal fitness regimen, so she’s ramped up her yard work by transplanting several shrubs and expanding her perennials. The basement is looking tidier now that she’s cleaned it out and donated old furniture and equipment that was gathering dust.

Without the daily commute into the city, she even has an extra hour or two to apply toward a consistent eight hours of sleep per night. “I’m not sure I’m any fitter than I was pre-covid,” she says. “But I definitely feel healthier.”

Amby Burfoot is a freelance writer and editor and a member of the Running Hall of Fame. His most recent book is “Run Forever: Your Complete Guide to Healthy Lifetime Running.”