The power of 10 more minutes of exercise

You may already know that the US government's current recommendations are for adults to participate in "moderate-to-vigorous" exercise for at least 150 minutes per week. That's usually described as 30 minutes of exercise 5 days per week.

Not long ago we reported on a study that suggested that those who exercised even more vigorously than those who exercised the same amount of time but at a moderate intensity were about 20% less likely than their moderately-exercising peers to die of a cardiovascular-related disease.

This sort of thing makes great headlines, but the bad news is that many people hear a vastly oversimplified version of that message - "Just exercise 30 minutes a day but even harder than you are already!" - and go home and lie down.

As is so often the case, further research has found that the question of exercise is far more nuanced than previously thought.

In a letter published in JAMA Internal Medicine in January of 2022 (2022;182(3):349-352), researchers at the National Cancer Institute and the Centers for Disease Control (CDC) reported on an analysis of National Health and Nutrition Examination Survey (NHANES) data in a subset of over 4800 participants between the ages of 40 and 85 between 2003 and 2006.

That subset is particularly important because these participants wore accelerometers (devices that measure physical activity) for 7 consecutive days, allowing the researchers to accurately measure their actual amount of physical activity - as opposed to relying on the participants' personal recall, which is notoriously inaccurate.

With the information gathered from the participants' accelerometers the authors could group the participants into 8 increasing levels of moderately vigorous activity: 0-19 minutes per day, 20-39, 40-59, and so forth up to a maximum of 140 or more minutes per day. These included participants with clinically diagnosed frailty as well as those who required equipment to walk, which the authors assumed were unable to increase their level of activity.

The authors then analyzed the number of deaths in this subset of participants as of the end of 2015 and extrapolated the activity levels and deaths to the population of the US as a whole - NHANES is deliberately designed to be representative of the US population.

With the minutes of activity correlated with the number of deaths, the authors could then model the number of deaths that might occur at higher levels - more minutes - of moderately vigorous physical activity. First they added just ten minutes of physical activity, then 20, then 30 minutes per day.

They found that adding just 10 minutes of moderately vigorous physical activity per day would result in 6.9% fewer deaths per year - or over 111,000 fewer deaths among all Americans per year. Adding 20 minutes per day reduced deaths by 13% (over 209,000 fewer Americans) and 30 minutes by 16.9% (over 272,000 deaths)/

What this means for you

If you're not currently very active, it's easy to get overwhelmed when thinking about starting an exercise plan: "150 minutes a week? Where am I going to find that kind of time?"

This study looked at people who engaged in moderately vigorous physical activity - which is defined as "physical activities... that cause only light sweating or a slight to moderate increase in breathing or heart rate." This was measured by motion-sensitive devices (accelerometers) which allowed the researchers to determine when the participants had that "slight to moderate increase in breathing or heart rate", which could well have meant several short bursts of exercise per day, such as a walk across the Target parking lot carrying several bags, a brisk walk of the dog, and playing with the grandkids.

The point here is that just 10 more minutes of that level of activity per day had a measurable impact on the participants' risk of death from all causes - even when they had mobility issues. You don't need to pay for spin classes six days a week to see the benefits of just a little more exercise, just a willingness to spend an extra ten minutes per day, perhaps walking around the block.

Related

Underscoring the importance of moderate exercise
Current recommendations are for adults to engage in at least 150 minutes of "moderate-to-vigorous physical activity" each week for reasons including improved cardiovascular outcomes. "Moderate activity" is defined as "physical activities... that cause only light sweating or a slight to moderate increase in breathing or heart rate" while "Vigorous activity" is defined as a physical activity that causes "heavy sweating or large increases in heart rate."

Get your exercise
An international study suggests that more exercise reduces your risk of death - regardless of your weight.

Exercise because it's fun
As you know, you can lose weight just by cutting calories, but it's much easier to lose weight if you diet and exercise. The trick for many people, however, is that exercise makes them hungry - and so they eat more than they should. But not everyone does - there is research to show that some people are less hungry after exercise. Why?