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The development of physical activity monitors does not lead to the development of physical activity – men, women, children and adults in developed countries move less
Jul
Global sales of fitness trackers have grown from $14 billion in 2017 to more than $36 billion in 2020The meteoric success of these gadgets suggests that more people than ever are seeing value in tracking the number of steps they take, the floors they climb, the time they spend sitting and the calories they burn.
The manufacturers of these devices certainly want consumers to believe that tracking physical activity and health-related behaviors will encourage them to escalate their activity levels and, in turn, improve their health.
Our analysis of research published over the past 25 years suggests otherwise.
We are professors of kinesiology – the science of human body movement – at Boise Statethis University of Tennessee and University of North FloridaTo find out if and how physical activity has changed in the years since fitness trackers became popular, we analyzed more than two decades of research from several industrialized countries – all conducted before the COVID-19 pandemic.
Our systematic review of data from eight developed countries around the world shows that while sales of fitness trackers are on the rise, physical activity has decreased from 1995 to 2017. Moreover, we found that this was not an isolated effect in one or two countries, but a widespread trend.
Browsing Research
To conduct the study, we first searched for published studies that tracked physical activity, such as walking, household chores, or sports, throughout the day. We wanted studies that would obtain two “snapshots” of daily activity from a population, with the measurements separated by at least a year.
We found 16 studies from eight different countries that met these criteria: Canada, Czech Republic, Denmark, Greece, Japan, Norway, Sweden, and the United States. The studies were conducted between 1995 and 2017.
It’s crucial to note that these snapshots didn’t track specific individuals. Instead, they tracked samples of people from the same age group. For example, one Japanese study of physical activity among adults aged 20 to 90 collected data every year for 22 years from people in each age group.
The researchers monitored the participants’ physical activity using a variety of wearable devices, from elementary pedometers to more advanced activity trackers such as accelerometers.
The study groups included both enormous, nationally representative samples of tens of thousands of individuals and petite samples of several hundred students from several local schools.
Once we identified the studies, we calculated an “effect size” for each study. An effect size is a method of adjusting data to allow comparison of “similar” results. To calculate the effect size, we used the data provided by the studies. This included average physical activity at the beginning and end of each study, the sample size, and a measure of the variability of physical activity. Using a technique called meta-analysis, we were able to combine the results from all the studies to get an overall trend.
We found that, overall, researchers documented fairly consistent declines in physical activity, with similar declines in every geographic region and in both sexes. Overall, the decline in physical activity per person was more than 1,100 steps per day between 1995 and 2017.
Our most striking finding was how rapidly physical activity among 11- to 19-year-olds has declined—by about 30%—over the course of a single generation. For example, when we compared studies reporting physical activity in steps per day, we found that the total number of steps per day per decade declined by an average of 608 steps per day in adults, 823 steps per day in children, and 1,497 steps per day in adolescents.
Our study does not address why physical activity has declined over the past 25 years. However, the studies we reviewed mentioned some contributing factors.
More staring at screens, less walking and cycling
Among adolescents, declines in physical activity were associated with increases in ownership and employ of smartphones, tablets, video games and social media.
For example, in the US, screen time among teenagers has increased dramatically, with five hours a day in 1999 Down 8.8 hours per day in 2017.
At school, most of the physical activity that teenagers engage in traditionally comes from physical education classes. However, the changes in the frequency of physical education classes during the study period are inconsistent and vary by country.
All of these factors may lend a hand explain the decline in physical activity we observed in our study.
In addition, fewer adults and children walk or bike to school or work than they did 25 years ago. For example, in the overdue 1960s, most U.S. children between the ages of 5 and 14 I rode a bike or walked to schoolSince then, this “vigorous transport” has largely have been replaced by car tripsPrices for school bus and public transport have not changed substantially.
So why employ a fitness tracker?
So if physical activity levels have declined at the same time that fitness tracking has risen in popularity, what makes these gadgets useful?
Fitness trackers can lend a hand people become more aware of their daily physical activity. However, these devices are only part of the solution to the problem of sedentary lifestyles. They are people who facilitate rather than drive behavior change.
[Over 150,000 readers rely on The Conversation’s newsletters to understand the world. Sign up today.]When a person’s physical activity level drops, it opens the door to an overall decline in fitness levels and other health problems, such as obesity or diabetes. On the other hand, physical activity has a dramatic positive effect about health AND well-beingThe first step to increasing vigorous movement is to measure it, which these devices can do. However, effectively increasing overall physical activity requires several additional factors, such as goal setting, self-monitoring, positive feedback, and social support.
