- Meeting the government’s physical activity guidelines can lower your risk of dying, but so can any level of exercise.
- People who engage in sufficient aerobic activity are 29 percent less likely to die from any cause, according to a new study.
- The lowest risk of dying occurs between 150 and 300 minutes a week of moderate-intensity aerobic activity.
Exercise offers a number of health benefits, from boosting your mood to lowering your blood pressure to giving you a chance to socialize with your friends.
It can also lower your risk of death — especially if you regularly meet the government’s physical activity guidelines — according to a new study published July 1 in The BMJ.
“This was a nice study, and supports the idea of physical activity being an important lifestyle behavior that can improve health and well-being,” said John Jakicic, PhD, an exercise physiologist in the University of Pittsburgh’s School of Education, who wasn’t involved in the new research.
Benefits of meeting physical activity guidelines
The 2018 Physical Activity Guidelines for Americans recommends that people do at least 150 minutes a week of moderate-intensity exercise, or 75 minutes a week of vigorous-intensity physical activity, or a combination of both.
People should also aim to do moderate- or vigorous-intensity muscle strengthening activities on 2 or more days a week.
In the new study, researchers looked at responses to the U.S. National Health Interview Survey (NHIS) for 1997 to 2014 to see if people met the physical activity guidelines. This included almost 480,000 Americans ages 18 and older.
Researchers also looked at national death records to identify how many of these people had died by the end of 2015.
Compared to people who didn’t meet the recommended activity levels, people who engaged in sufficient aerobic activity were 29 percent less likely to die from any cause.
Those who met the recommended muscle strengthening activity level had an 11 percent lower risk of dying from any cause.
People who met the recommendations for both aerobic and muscle strengthening activities achieved even larger benefits — a 40 percent lower risk of death from any cause.
“The results show that either aerobic or resistance exercise at [the recommended] levels was beneficial,” said Jakicic. “However, it appears that a combination [of the two] is even more beneficial at reducing all-cause mortality.”
Similar benefits were observed for deaths from cardiovascular disease, cancer, and chronic lower respiratory tract diseases.
The study had a few limitations, including its observational nature, which means the researchers can’t show cause and effect.
People also self-reported how physically active they were, which isn’t as accurate as using an activity monitor (aka accelerometer).
But Jakicic said the large nature of the study provides “some level of confidence” in the results. It also fits with other research showing the benefits of exercise.
Less exercise is still beneficial
Jakicic said the new study shows that the 2018 Physical Activity Guidelines for Americans are still a “good barometer” for how much movement you should aim to do each week.
One graph in the scientific report that accompanies the guidelines highlights where the “sweet spot” is, at least for aerobic activity.
The lowest risk of dying occurs between 150 and 300 minutes a week of moderate-intensity aerobic activity (or the corresponding amount of vigorous-intensity activity).
If you exercise more, you get some additional benefit, but not much. There’s also a greater risk of overuse injuries at higher volumes of exercise.
However, the sharpest increase in benefit occurs early on — just by getting off the couch.
“Even if you’re not meeting the recommendations, you’re getting substantial health benefits by not being sedentary,” said Linda S. Pescatello, PhD, a kinesiology professor at the University of Connecticut.
These benefits also apply to people with chronic disease, as long as they’re exercising safely — which sometimes means talking to their physician first. This is something that both the new study and the physical activity guidelines emphasize.
“The scientific report [for the guidelines] shows that the people who stand to benefit the most from exercise are the people who need it the most,” said Pescatello. “And that would include people with chronic diseases and conditions.”
However, despite the evidence, very few Americans meet these guidelines.
The authors of the new study found that only 16 percent of people met the physical activity guidelines for both aerobic and muscle strengthening activity. This is lower than the 23.2 percent seen in the more recent 2018 NHIS.
The researchers point to “lack of time” as keeping some people from exercising, and suggest that those pressed for time focus on aerobic activity because of the greater benefits seen in this study.
However, Pescatello said the way muscle strengthening activities were counted in the study makes it difficult to compare them directly to aerobic activities.
Muscle strengthening activities were based on how often people did them, rather than for how long. This is the same way the guidelines count them.
The health benefits of this type of exercise, though, also depend on how hard you work out, said Pescatello — which in turn depends on the type of exercise, as well as the number of repetitions and sets.
In addition, some types of physical activity — such as circuit weight training and high-intensity interval training (HIIT) — can combine both aerobic and muscle strengthening.
“This can be used to reduce the total time it takes to see benefits,” said Pescatello.
Even yoga can be both aerobic and muscle strengthening, not to mention increase flexibility, balance, and coordination.
“If you want to talk about a time-efficient workout,” said Pescatello, “Two yoga sessions a week could meet the [aerobic and muscle strengthening] recommendations.”