Originally Published: 17 OCT 22 11:00 ET

Updated: 17 OCT 22 12:09 ET

By Sandee LaMotte, CNN

(CNN) -- Physical activity guidelines for older adults stress doing at least two days of strength training and 2½ hours of moderate to vigorous aerobic physical activity each week. Yet many people downplay muscle strengthening, relying on the heart-pumping benefits of aerobic exercise.

That would be a mistake, a new study found. Independent of aerobic physical activity, adults over 65 who did strength training two to six times per week lived longer than those who did less than two, according to study author Dr. Bryant Webber, an epidemiologist in the Division of Nutrition, Physical Activity, and Obesity at the US Centers for Disease Control and Prevention.

"We found that each type of physical activity was independently associated with a lower risk of all-cause mortality in older adults," Webber said in an email.

"Those who met the muscle-strengthening guideline only (versus neither guideline) had (a) 10% lower risk of mortality, those who met the aerobic guideline only had 24% lower risk of mortality, and those who met both guidelines had 30% lower risk," he said.

The results applied to all ages groups, even the most elderly, according to the study published Monday in the journal JAMA Network Open.

Peope who were 85 and older who met both the aerobic and muscle-strengthening guidelines had a 28% lower risk of dying from any cause than people over 85 those who met neither of the guidelines, the study found.

"This finding suggests that aerobic and muscle-strengthening physical activity is valuable throughout the lifespan," Webber said.

The study looked at leisure and other physical activity gathered by the National Health Interview Survey, an ongoing investigation of American health done by the CDC. Information on strength training and aerobic activity by age group was then compared with deaths over an average of eight years.

The study controlled for demographics and marital status, body mass index, history of smoking or alcohol consumption, and presence of asthma, cancer, diabetes, chronic obstructive pulmonary disease, heart disease, hypertension and stroke.

Looking only at the data on strength training, the study found adults who did two to three sessions or four to six sessions of muscle strengthening exercise per week had a lower risk of death for any reason than adults who did strength training less than twice weekly.

Doing more wasn't beneficial — the study found seven to 28 sessions of strength training weekly did not offer additional protection.

You don't have to go to a gym to strengthen your muscles, the CDC said. You can lift weights at home, work with resistance bands, use your body weight for resistance (for example, push-ups and sit-ups), and dig or shovel in the garden. Even "lifting canned goods could be considered a muscle-strengthening activity," Webber said.

The goal is to work all the body's major muscle groups: abdomen, arms, back, chest, hips, legs and shoulders.

Looking only at the data on aerobic exercise, the study found that doing 10 to 300 minutes per week was associated with a lower risk of death from any cause compared with doing less than 10 minutes per week.

Aerobic activity can include walking, bike riding, hiking, raking leaves and pushing a lawn mower and water exercises, to name a few.