The New York Times recently carried an article on the increasing popularity of step counters such as Fitbits. People like to see how many steps they can take in a day, in order to see how much exercise they are getting. While these devices are strong motivators for many individuals, there are some problems associated with their use.
For one thing, not all steps are equal in terms of building aerobic fitness. A slow walk in the park will not raise your heart and breathing rates as much as a mad dash to catch the train before it leaves the station. For another, focusing exclusively on steps ignores other forms of exercise, which may be equally beneficial. Weight training, for example, is extremely important for maintaining muscle strength, especially for older individuals. Pumping iron can be a great workout, but it gets you no points on the step counter. Other everyday activities that can be good workouts, such as shoveling snow or raking leaves, require few steps. Steps are easier to count than other forms of movement, so this is what the fitness trackers rely on.
The Department of Health and Human Services recommends 150 minutes of “moderate to vigorous” exercise per week in order to reduce the risk of diabetes, certain cancers and cardiovascular diseases. Now the department has added Alzheimer’s disease, depression, anxiety, and insomnia to the list. However, many individuals will never perform vigorous exercise and seldom engage in moderate exercise. This is where light exercise and step counters come into the picture. On average, adults spend nine to eleven hours per day sitting. Getting some movement, even though it is light and unstructured, is better than sitting.
A study examining the relationship between steps and mortality was published in JAMA Internal Medicine. 16,000 female volunteers, average age 72, were given step trackers to wear for a week. Four years later they were contacted to see how many were still living. Quite clearly, those who took the most steps had the lowest mortality. In addition, the study revealed that benefits seemed to plateau at 7,500 steps even though the popular goal is 10,000.
My criticism of the study is that it is possible that the individuals who were in the best shape at the start of the study naturally walked more and were also less likely to die. Possibly the walking was merely associated with the findings and not the cause.
Criticisms aside, getting people motivated to exercise more, be it vigorous, moderate or light, is a worthy goal, and Fitbits are a step in the right direction.