Early Mortality Risk Reduced up to 40% with Increased Physical Activity

shutterstock_63941128The dose-response relationship between physical activity and overall human health is not very well defined. That is, scientists are still unsure exactly how much physical activity any given person needs in order to keep their body healthy in the long term. To help shed light on this issue, a researcher in physical activity and public health, Guenther Samitz, based at the University of Vienna at the Centre for Sports Sciences and University Sports investigated this dose-response relationship involving more than 1.3 million people from Europe, Canada, the U.S., and Asia. Samitz and his colleagues used a meta-analysis, which combined the results of 80 individual studies over the course of about 11 years that addressed questions surrounding the dose-response issue.

As many of us already know, lack of physical activity could lead to heart disease, high blood pressure, strokes, depression, increased weight, and instances of cancer. With busy schedules, it can be difficult to find time or energy after work, school, or kids to dedicate to exercise. However, the study provides a good incentive to take the steps necessary to a healthy future.

What was found through the study by Samitz was that higher levels of physical activity were associated with lower all-cause mortality rates, and the more vigorously a person exercises, the lower their risk. Mortality is defined as chronic diseases and/or premature death. Of course, external factors like smoking, diet, social and educational factors also play a role in a person’s overall health and mortality. These factors were considered when reporting the results of the study.

What was also interesting about the results was that women tend to experience a greater benefit than men do when they incorporate light- to moderate-level leisure physical activity into their daily routines, such as gardening, biking, climbing stairs, or walking. Researchers were unclear as to why women benefit more than men do, but one hypothesis is that hormone levels and body fat distribution may play a role.  For both men and women, making the change from no activity to just one hour of light- to moderate-level physical activity per week showed a 4% reduction in mortality.

As expected, the more a person exercises per week, the lower the mortality rate they will experience. According to the World Health Organization (WHO), 6% of deaths globally are attributed to physical inactivity. The WHO recommends 5 hours of activishutterstock_72007540ty per week for extended health benefits. These benefits, which were consistent with Samitz’s research, include a decrease in mortality risk by 19% for moderate-level activity, and 39% for vigorous-intensity aerobic activity and sports.

It isn’t that difficult to get started with increasing your daily physical activity. Simple activities like walking up the stairs rather than taking  the elevator, biking to the grocery store, joining an exercise class at a local gym or school, gardening, or taking the dog out one extra time per day can be beneficial.

Guenther Samitz explains, “…sedentary adults should start with moderate-intensity physical activities and slowly increase weekly dose and intensity, because in sedentary adults vigorous-intensity physical activity is associated with increased risk of musculoskeletal injuries and adverse cardiac events”

The results of the study have been published in International Journal of Epidemiology. You can read report’s abstract and full text here. More interesting and useful information can be found on the WHO website:  10 facts about physical activity.

Image Credits:


Warren Goldswain/Shutterstock

by Sara Stefanski

  • Edyth-Anne
    Oct 31st, 2011 at 20:32 | #1

    Important information! The links are particularly helpful for women.

  • Guenther Samitz
    Nov 3rd, 2011 at 05:00 | #2

    Dear Sara,
    thank you for having placed our meta-study on your website. It´s a remarkable well written story and I explored your high quality website. It is in line with my personal philosophy of life (e.g. I live in a passive house, prefer public transportation and active commuting…)

    Just to make two points clearer.

    1.) All-cause mortality (=total mortality): about 75% of total mortality is due to cardiovascular disease(e.g. coronary heart disease, cerebrovascular disease (e.g. stroke) and cancer.

    2.) Dose-response relation:
    Our study showed that an increment of 1 hour per week in a) light- to moderate-intensity activity (e.g. domestic work, repair, gardening, walking as part of daily life, active commuting) was associated with a 4% reduction in all-cause mortality.
    b) Moderate to vigorous-intensity leisure activity (e.g. gymnastics, social dance, golf, resistance exercise, aquatic exercise, bicycling (8-10 miles/h), nordic walking, hiking) was associated with a 6% reduced mortality rate.
    c) Vigorous endurance exercise or sports (e.g. running, bicycling >10 miles/h, mountain biking, tennis, basketball) was associated with a 9% reduced mortality risk per increment of one hour per week.

    Vigorous-intensity exercise expend more total energy per unit of time than do lower intensity activities. This is the main reason why the mortality reduction is higher for vigorous-intensity activity. As a rough rule: 30 minutes of jogging will nearly expend the same amount of energy as 60 minutes of brief walking do, and the health benefit will be comparable.

    All best from Vienna

  • Nov 3rd, 2011 at 16:38 | #3

    Hi there Guenther! I am honored that you read and enjoyed the post. Thanks for exploring our site!

    I appreciate your points about all-cause mortality and dose-response relationships. In your opinion, do you think there will be a time when doctors and scientists can give customized dose-response information to individuals/patients based on their metabolism, diet, lifestyle, etc?

    I really enjoyed reading about your work! Thanks so much for your input.


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