- Experts recommend 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous exercise per week.
- This study adds to the evidence that even modest amounts of physical activity have health benefits.
- All physical activity counts, and it’s never too late to become more active and see benefits.
Let’s face it. Some weeks, picking kids or grocery bags up from the floor is about as close as we’re going to get to doing squats—or any form of exercise for that matter. The thought of even attempting to get 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous physical activity in one week—the minimum amount of exercise official guidelines recommend—has some of us saying, “Maybe when I retire, I’ll have time for that.”
Yes, it can seem daunting at times to get even the minimum amount of exercise, but there is mounting evidence that any amount of exercise, no matter how small, may have some benefits. For example, a study found that even brief bursts of exercise, such as 5 minutes at a time, may have a positive effect on blood pressure. Another study found that exercising just one day a week could reduce the risk of diabetes.
Researchers from Australia conducted a large systematic review and meta-analysis to determine how much physical activity over adulthood is correlated with a reduction in dying from anything (scientifically referred to as all-cause mortality). They also wanted to know how much physical activity is related to preventing death from cardiovascular disease and cancer. They published their findings in the British Journal of Sports Medicine. Let’s break down what they found.
How Was This Study Conducted?
Researchers searched for previously conducted studies on the topic of physical activity and mortality. They looked for studies that included all-cause mortality, as well as death from cardiovascular disease and cancer. After sifting through over 33,000 potential studies, they identified 85 studies that met their criteria. This is a large amount of data for a systematic review and meta-analysis, which helps increase the validity of the findings.
Many studies on the effects of physical activity and health tend to take a snapshot in time regarding participants’ physical activity levels, and don’t account for changes in physical activity levels over time. These researchers aimed to look at physical activity over extended periods, so they categorized the data based on physical activity habits. The categories included consistently active people, those who increased physical activity over time, those who decreased their physical activity over time, and those whose physical activity varied over time, with a cumulative average amount of physical activity.
They further divided physical activity into overall physical activity and leisure-time physical activity.
- Overall physical activity includes both intentional exercise and general activity levels (e.g., do you spend most of your day sitting, or are you more active). It could also include housework and yard work—any activities you do as part of living.
- Leisure-time activity includes more intentional physical activity, like going for a walk or hike, weight training, sports activities and fitness classes.
What Did This Study Show?
After running statistical analyses, the results showed:
- Consistently active levels of total physical activity were associated with a 29% lower risk of all-cause mortality.
- Consistently active levels of leisure-time physical activity were associated with a 39% lower risk of all-cause mortality.
- Participants who increased their total physical activity from inactive to active levels had a 22% lower risk of all-cause mortality compared with those who remained inactive.
- Those who increased their leisure-time physical activity had a 27% lower risk of all-cause mortality.
- Compared with participants who were consistently inactive over time, those who were consistently active in either total or leisure time had around 40% and 25% lower risk for CVD and cancer mortality, respectively.
Researchers also looked at the dose-response for physical activity. In other words, how much physical activity does it take to see a decrease in risk? Here’s what they found:
- Compared with being consistently inactive, being consistently active at 8.75 mMET.h/ week (the lower end of the current physical activity guidelines) was associated with around 40% lower risk of all-cause mortality, and the risk reduction increased to around 46% at the upper bound of the recommended level, 17.5 mMET.h/week (the upper end of the guidelines). However, a further increase in physical activity levels to 30 mMET.h/week only had about a 5% additional risk reduction. This means that going beyond current guidelines will provide you with a slight additional benefit, but not a significant one.
- Compared with being consistently inactive, increasing from 0 to 8.75 mMET.h/week was associated with around 25% lower risk of all-cause mortality; however, additional increases beyond 17.5 mMET.h/week did not seem to have additional risk reductions.
While not strong evidence, there was some indication that people who decrease their physical activity over time may still reap the benefits of reduced risk of death, about 17% reduced risk of all-cause mortality. Researchers hypothesize that it may have to do with the body’s “banking up” of health benefits from previous higher levels of physical activity.
As with any research, this study has a few limitations. First, participants’ physical activity was self-reported, which always leaves room for bias. There were also only a few studies included in the review that considered cumulative physical activity over time or cancer deaths. Less data means results may not be as accurate as they would be if more data were available.
How Does This Apply to Real Life?
This study suggests that being consistently active reduces the risk of all-cause mortality or dying from heart disease, regardless of when one starts being consistent; however, those who are more consistent throughout their lifetimes appear to gain the most benefits. It also suggests that if you have to reduce the amount of physical activity as you age or at certain times in your life, you may still maintain some benefits.
This means that no matter where you are on the physical activity spectrum, it’s never too late to start being more active. And as with any habit, being consistent with it is what will make the difference in helping the habit to stick.
If you want to be more active, consider where you’re currently at with exercise. If you’re starting from scratch, brainstorm ways to get started moving more. Maybe this means parking at the far end of the parking lot or taking the stairs instead of the elevator. Do more trips back and forth from the car into the house with groceries, or from the laundry room to the bedrooms to put clothes away. If you have a desk job, can you get a stand-up desk? Not only does standing require using more muscles than sitting, but it’s also easier to incorporate leg exercises into your day. You can also fit a walking pad under it and walk slowly while you work (this will also exercise your brain!).
Habit stacking is a great habit hack to try. Consider habits you already have, like brushing your teeth or watching your favorite TV show in the evening. Can you do squats while you brush? How about doing a simple strength training or stretching routine while you’re watching TV? Push-ups, dips, squats, lunges and planks are all bodyweight exercises that can be done during commercial breaks.
When you take the time to brainstorm possibilities, you can come up with some pretty creative ways to incorporate more activity into your day. Don’t be afraid to think outside the box. Just because it doesn’t fit the mold of traditional exercise doesn’t mean it doesn’t matter.
Our Expert Take
This study suggests that being consistently or increasingly active is associated with a 20–40% risk reduction in all-cause mortality and a 30–40% risk reduction in cardiovascular disease mortality. This review also suggests that you may reduce your risk of all-cause mortality and dying from cardiovascular disease by about 40% if you are consistently meeting current physical activity guidelines. Even if you have to decrease your physical activity levels, you may still retain some benefits. Remember, all movement counts. So be intentional and creative and look for ways to move more that feel good and fit your lifestyle and preferences.
