Exercise Science: Even "Very Low Levels" Can Have Lifelong Health Benefits

In September, scientists identified the smallest amount of exercise needed to improve brain function. Now, in an effort to help us keep changing our habits as little as possible while maximizing health benefits, another study has even better news. An analysis in The British Medical Journal reports that incredibly short amounts of very easy exercise can have powerful effects.

Specifically, these researchers in China showed that activities like gardening, walking, or dancing in a non-vigorous, leisurely way for 10 minutes to an hour per week was associated with an 18-percent lower risk of death compared to people who did nothing. And the more time people spent doing these chill exercises, the better they fared. People who went above and beyond and did at least 150 minutes per week (that’s at least 30 minutes every weekday) had a 34-percent lower risk of death over the course of the study.

In the paper, lead study author Dr. Bo Xi, an associate professor at Shandong University’s School of Public Health, and his co-authors write that their findings drive home one major point: All exercise, even the smallest, easiest amount, can have lasting benefits. An easy 10-minute workout may not help you outrun a marathoner, but it may help you outrun death.

“Currently, about 51 percent US adults fail to meet the recommendation for physical activity” they write. “Very low levels of physical activity, such as about 5–10 min/day may be easy to achieve by most adults.”

This study drew on data from 12 editions of the National Health Interview Survey between 1997 and 2008. In total, 88,140 people between 40 and 85 years old answered those surveys, providing information about their health, how much leisure activity they did per week, and how much vigorous activity — like organized sports or running hard. When the authors adjusted for factors like how much hard exercise the participants did as well as other risk factors like BMI, smoking, or alcohol use, they still found that as little as 10 minutes per week of leisurely exercise was still associated with decreased risk of death.

But they make it clear that for anyone who wants to step it up, they can aim higher. Going harder, they report, has “added benefits” for reducing mortality — though they don’t specifically put a percentage on it. It’s also just more time-effective. In their analysis, they equate one minute of vigorous activity with roughly two minutes of leisurely activity — which is echoed in the World Health Organization’s guidelines as well. The WHO’s guidelines suggest people perform at least 150 minutes of moderate intensity aerobic exercise per week, which they list as walking, dancing, gardening, or swimming — or attempt 75 minutes of vigorous exercise per week. This study’s findings are right in line with those guidelines, but they also give people a bit more wiggle room.

Even if you’re not planning on going for the full 150 minutes, moving even just a little bit can have an impact down the line.

Abstract:

Background: Evidence on the role of very low or very high volumes of leisure time physical activity (PA) on the risk of all-cause and cause-specific mortality is limited. We aimed to examine the associations of different levels of leisure time PA with the risk of all- cause, cardiovascular disease (CVD) and cancer-specific mortality.

Methods: Data were from 12 waves of the National Health Interview Surveys (1997–2008) linked to the National Death Index records through 31 December 2011. A total of 88 140 eligible participants aged 40–85 years were included.

Results: Compared with inactive individuals, those performing 10–59 min/week of PA had 18% lower risk of all-cause mortality (hazard ratio (HR): 0.82, 95% confidence interval (CI): 0.72–0.95). Those who reported 1–2 times (150–299 min/week) the recommended level of leisure time PA had 31% (HR: 0.69, 95%CI: 0.63– 0.75) reduced risk of all-cause mortality. Importantly, the continued benefits were observed among those performing leisure time PA 10 or more times (≥1500 min/week) the recommended minimum level (HR:0.54, 95% CI: 0.45–0.64). For 10–59, 150–299 and ≥1500 min/week of PA, the corresponding HRs (95% CIs) for CVD-specific mortality were 0.88 (0.67–1.17), 0.63 (0.52–0.78) and 0.67 (0.45–0.99), respectively: for cancer-specific mortality were 0.86 (0.66–1.11), 0.76 (0.64–0.89) and 0.53 (0.39–0.73), respectively. In addition, there was a larger reduction in all-cause and cause-specific mortality for vigorous vs. moderate intensity PA.

Conclusions: We found that beneficial association between leisure time PA and mortality starts from a low dose. Doing more vigorous exercise could lead to additional health benefits.