The Covid-19 Pandemia caused many countries to adopt a measure that many associated only with times of war, confinement. The reality blow to which the majority of people who could not leave home for almost 3 months were that, suddenly, our physical activity rates decreased drastically. We go from walking freely not to be able to do it. The result was that, even those who were not so active before the pandemic, had the imperative need to move. The lack of movement made ourselves realize that we had lost something that constitutes part of the essence of the human being: we are because we move.

How much was physical activity reduced in the confined population?

The easiest way to quantify how much we move is the steps . A study that compared the physical activity rates of the University of Pittsburgh in the years 2019 and 2020, that is, before and after the start of the pandemic, saw that the number of steps was drastically reduced. The students went from average 10,000 steps to 4,600 (1) (Figure 1). In addition, and this is a relevant fact, this decrease in physical activity rates was associated with an increase in depression rates. That is, the lack of physical activity impacts fully on our mental health.

It is currently relatively common that much of the population performs training in a structured way to alleviate the lack of daily physical activity. However, training an hour a day and being sedentary The rest of the time does not solve a problem that ravages much of the developed world: we do not move enough. While our ancestors walked around 9-15 km/day, currently sedentary people do not exceed 5. Therefore, a relatively simple strategy to increase physical activity levels would increase the number of steps we take per day. So the question we have to ask is, how many steps are necessary to be healthy?

If we analyze the current situation, globally the average daily steps is ~ 5,000 (2). This is far from the limit that many have believed as the threshold to be healthy, the famous 10,000 steps. Although it is used commonly to prescribe physical activity, the origin of the objective of the 10,000 steps per day is not clear. It is probably derived from the commercial name of a pedometer that was sold in Japan in 1965 called Manpo-Kei, which translates as a “10,000 steps meter” (3). To alleviate this knowledge emptiness, different research is looking for the optimal dose-response that could help prescribe physical activity in a more precise way. Studies conducted in Australia (n = 2,576 participants) (4) and in Britain (n = 1,655 participants) (5) have seen that a greater number of steps is associated with lower mortality rates. For example, in Australians, each increase of 1,000 steps/day was associated with a 6%mortality risk reduction, and in the 14%British participants.

What number of steps reduces the risk of mortality to a greater extent?

While this question is difficult to answer, a meta-analysis recently published by the prestigious Sports Medicine after analyzing more than 175,000 people saw how the risk of mortality decreases linearly from 2,700 steps to 17,000 (6). For each increase of 1,000 steps, the risk is reduced by 12%, even for people over 70. These results suggest that any moderate increase can help us improve our health. In addition, the objective of 10,000 steps is not the amount where the greatest benefits are obtained. Compared to walking 2,700 steps, 10,000 steps reduce the risk by 56%, while 16,000 do it by 66%. In this case, more seems better.

Adapt the steps limit to age

We must bear in mind that the objective of steps should not be the same for a 20 -year -old person as for a 80, since as we get older the amount of steps we take decreases (2) (Figure 3). While a greater number of steps improves health, the situation of many people makes it not realistic to tell them for example 12,000 steps a day. Therefore, it is necessary to establish objectives appropriate to the age and the reality of each person. Thus, for example, a study published in JAMA Internal Medicine (7) that analyzed 16,741 women of 72 years of middle ages, saw how to move from 2,700 steps to 4,400 already reduced the risk of mortality by 41%. In addition, the benefits reached up to 7,500 steps, while beyond this threshold no significant improvements were seen.

Conclusions

Walking is part of the essence of the human being. At a time when sedentary lifestyle are alarming, prescribing "steps" can be a simple formula to improve the health of the population globally. In this sense, if we walk little, any increase in the number of steps will have benefits in our health. And for we do not comply with this, the benefits are greater the more we walk. In terms of steps, more seems to be better. However, not to reduce the "recipe" to only take the greatest number of steps we can, walk must be the basis of our daily physical activity. On it we must build an integral health, and if in addition to walking we train, the benefits will be greater.

In a world where the population is increasingly long, we must be aware that high levels of physical activity can help us attenuate the speed at which we age. To be healthy, we must move more. 

References:

1. Giuntella O, Hyde K, Saccardo S, Sadoff S. Lifestyle and Mental Health Disruptions During Covid-19. Proc Natl Acade SCI [Internet]. 2021 Mar 2; 118 (9): E2016632118. Available from: http://www.pnas.org/content/118/9/e201632118.abstract

2. Althoff T, SOSIč R, Hicks JL, King AC, Delp SL, Leskovec J. Large-Scale Physical Activity Data Reveal Worldwide Activity Inequality. Nature [Internet]. 2017; 547 (7663): 336–9. Available from: https://doi.org/10.1038/nature23018

3. Tudor-Locke C, Bassett DR. How Many Steps/Day Are Aough? Sport Med [Internet]. 2004; 34 (1): 1–8. Available from: https://doi.org/10.2165/00007256-200434010-00001

4. Dwyer T, fish A, Sun C, Cochrane J, Venn A, Srikanth V, et al. Objectively Measuraled Daily Steps and Subsequent Long Term All-Cause Mortality: The Tasped Prospective Cohort Study. PLOS One. 2015; 10 (11): E0141274. 

5. Jefferis BJ, Parsons TJ, Sartini C, Ash S, Lennon Lt, Papacosta or, et al. Objectively Measured Physical Activity, Sedentary Behaviour and All-Cause Mortality in Older Men: Does Volume of Activity Matter More than Pattern of Accumulation? Br J Sports Med [Internet]. 2019 AUG 1; 53 (16): 1013 LP - 1020. Available from: http://bjsm.bmj.com/content/53/16/1013.abstract

6. Jayedi A, Gohari A, Shab-Bidar S. Daily Step Count and All-Cause Mortality: A DOSE-Response Meta-Analysis of Prospective Cohort Studies. Sport Med [Internet]. 2021; Available from: https://doi.org/10.1007/s40279-021-01536-4

7. Lee Im, Shiroma Ex, Kamada M, Bassett Dr, Matthews CE, Buring je. Association of Step Volume and Intensity With All-Cause Mortality in Older Women. Jama Intern Med [Internet]. 2019 AUG 1; 179 (8): 1105–12. Available from: https://doi.org/10.1001/jamainternmed.2019.0899

8. Dwyer T, Ponsonby Al, Ukoumunne OC, Pesic A, Venn A, Dunstan D, et al. Association of Change in Daily Step Count Over Five Years With Insulin Sensitivity and Adiposity: Population Based Cohort Study. BMJ [Internet]. 2011 Jan 13; 342: C7249. Available from: http://www.bmj.com/content/342/bmj.c7249.abstract