A recent JAMA study explored the question “Are increased numbers of steps per day associated with lower mortality rates among older women?”
While step count was just one of the measures highlighted in the study, resulting national media coverage suggested a daily goal of 10,000 steps may be a meaningless benchmark, e.g., “Among older women, 10,000 steps per day not needed for lower mortality,” “What 10,000 steps will really get you” and “10,000 steps a day? How many you really need to boost longevity”. This is a dangerous representation of both the JAMA research and the Physical Activity Guidelines for Americans.
The study found that higher rates of activity were associated with significantly lower death rates. This aligns completely with the widely accepted view that sedentary behavior is harmful, some physical activity is better than none, and more moderate-to-vigorous-intensity activity is even better.
This is why scientific findings require context and the key questions about activity and health raised by the JAMA are important to examine.
- A one-size-fits-all approach for step count is a practical but imperfect measure of physical activity and that’s okay. We are sedentary as a society. While the 10,000-step threshold may very well have originated as part of a marketing strategy by a Japanese pedometer manufacturer in 1965, it remains a simple goal to communicate and an easy way to measure the impact of physical activity to improve one’s health.
- It’s difficult to accomplish goals that can’t be easily measured. While many argue that cardiorespiratory fitness remains the best predictor of death, it is challenging to use it as a primary indicator since the testing is cumbersome and it’s not readily available to all, making it unrealistic to obtain accurate and ongoing measures on a population level. However, participation in ongoing amounts of moderate and vigorous physical activity can help people be more physically fit.
- Avoid oversimplification when the health of the population is at stake. Several of the articles on the JAMA research did correctly acknowledge that some activity is better than none. However, any suggestions that this study allows the general population to rethink their activity requirements is irresponsible and dangerous. Although 4,400 steps per day is associated with longevity in older women, we should be cautious about over-extrapolating these data and, in so doing, setting the bar too low.
Journalists play an important role in communicating scientific and often technical information in ways that the lay public can readily understand. However, in doing so, it’s vital that they keep in mind the responsibility put upon them and the potential impact on public health – positive or negative – when doing so.