There is strong evidence showing that sedentary life may significantly increase the risk of cardiovascular (CV) disease and shorten the lifespan. However, the optimal number of steps, both the cut-off points over which we can see health benefits, and the upper limit (if any), and their role in health are still unclear.
In this meta-analysis of 17 studies with almost 227 000 participants that assessed the health effects of physical activity expressed by walking measured in the number of steps, we showed that a 1000-step increment correlated with a significant reduction of all-cause mortality of 15%, and similarly, a 500-step increment correlated with a reduced risk of CV mortality of 7%. In addition, using the dose–response model, we observed a strong inverse nonlinear association between step count and all-cause mortality with significant differences between younger and older groups.
It is the first analysis that not only looked at age and sex but also regional differences based on the weather zones, and for the first time, it assesses the effect of up to 20 000 steps/day on outcomes (confirming the more the better), which was missed in previous analyses. The analysis also revealed that depending on the outcomes, we do not need so many steps to have health benefits starting with even 2500/4000 steps/day, which, in fact, undermines the hitherto definition of a sedentary life.
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