Physical activity lowers mortality in a dose dependent manner!

Often, when we here about new science or studies on exercise and health we find ourselves thinking “I already knew that” or “Well of course it´s like that”. The study of today’s post is no exception, but adds another perspective. Arem et al concluded that exercising, on a population level, makes us live longer. Many previous studies have reached similar conclusions in a variety of ways. What this study gives us, however, is the answer to the following:

How much physical activity do we need in order to get the health benefits?

Does more physical activity equal more benefits?

To what degree?

The study followed Europeans and Americans from six different medical centers, ages 21-98 (median 62). Participants self- reported their physical activity at baseline and 14 years later. Among the 600 000 participants,  116 686 died during the study. The study used 150 minutes of moderate or 75 minutes of vigorous exercise a week as a reference for the basal level of physical activity (in line with the World health organization’s minimum goal for every adult).

Study findings

Participants exercising below the recommendations had a 20% lower mortality risk compared to those who didn’t exercise at all. Participants exercising 1-2 times above recommendations had a 31% lower risk. The beneficial threshold was found to be between 3-5 times above recommendations, giving that group a 39% lower risk of mortality compared to the no-activity group. No extra risk of mortality was found up to 10x above recommendations.

Thus, the exercise dose sweet-spot with regard to time efficiency and lowering mortality seems to be to exercise 1-3 times the minimum recommendations, i.e. 150-450 min moderate or 75-225 min vigorous exercise per week.
Sources:
1. Arem H. Leisure Time Physical Activity and Mortality: A Detailed Pooled Analysis of the Dose-Response Relationship. JAMA Intern Med. 2015 June 1; 175(6): 959–967.
2. WHO Physical activity guidelines. 20170401 http://www.who.int/dietphysicalactivity/factsheet_adults/en/

Article by @jonasliefke a member of team EBT, third year Medical Student with a Bachelor´s degree in Physiotherapy. www.jonasliefke.com