Trends in Physical Activity Among Americans Over the Last Decade
The Importance of Exercise
Regular exercise is vital for maintaining a healthy lifestyle. Research indicates that engaging in physical activity can significantly lower the risk of mortality from various causes. Additionally, consistent exercise helps mitigate the chances of developing chronic illnesses, including diabetes, certain cancers (notably colon and breast), obesity, hypertension, and degenerative bone and joint conditions such as osteoporosis and osteoarthritis.
Sedentary behaviors, which involve prolonged periods of inactivity, negatively affect metabolic function, bone mineral density, obesity rates, and vascular health. Activities such as driving, desk work, gaming, and watching television exemplify sedentary behaviors. It is crucial to recognize that these behaviors constitute a distinct health risk beyond merely lacking physical activity.
Recommended Levels of Physical Activity
Determining the appropriate amount of exercise for optimal health can be challenging. Since 2008, guidelines have been established to outline recommended physical activity levels, with an update released in 2018. The Physical Activity Guidelines for Americans suggest aiming for 150 to 300 minutes of moderate-intensity exercise weekly, which translates to approximately two and a half to five hours each week. Activities like cycling, walking, swimming, and active forms of yoga fall under this category of moderate exercise.
Changes in Exercise Habits Over the Past Decade
A recent study published in JAMA Network Open aimed to assess whether Americans have been following physical activity guidelines and how sedentary behaviors have evolved over the past decade. Researchers utilized data from the National Health and Nutrition Examination Surveys (NHANES) to analyze information from 27,343 participants aged 18 and older, collected between 2007 and 2016. The study examined various factors, including age, gender, and race, and found no significant differences in population distribution.
The findings revealed that adherence to physical activity guidelines remained relatively stable, with approximately 63% of participants meeting the criteria in 2007-2008 and 65% in 2015-2016. However, there was a notable increase in the time spent engaged in sedentary activities, rising from 5.7 hours per day in 2007-2008 to 6.4 hours per day in 2015-2016.
Study Limitations
It is important to consider the limitations of this study. The data relied on self-reported information from participants, which may be subject to recall bias. Incorporating data from accelerometers or similar devices that track physical activity and heart rate could provide a more accurate validation of the findings.
The Path Forward: Move More, Sit Less
The data suggest a pressing need for individuals to reduce sedentary time and increase their levels of moderate physical activity. Fortunately, even small adjustments in sitting time can lead to health improvements. Therefore, when your fitness tracker prompts you to get up and move, consider taking a short walk or getting a cup of coffee. The key takeaway is to prioritize movement throughout the day.
References
1. Warburton, D. E., Nicol, C. W., & Bredin, S. S. Health benefits of physical activity: the evidence. Cmaj 174, 801-809 (2006).
2. Physical Activity Guidelines for Americans 2nd edition (2018).
3. Owen, N., Salmon, J., Koohsari, M. J., Turrell, G., & Giles-Corti, B. Sedentary behaviour and health: mapping environmental and social contexts to underpin chronic disease prevention. Br J Sports Med 48, 174-177 (2014).
4. González-Gross, M., & Meléndez, A. Sedentarism, active lifestyle and sport: Impact on health and obesity prevention. Nutrición Hospitalaria 28, 89-98 (2013).
5. Tremblay, M. S., Colley, R. C., Saunders, T. J., Healy, G. N., & Owen, N. Physiological and health implications of a sedentary lifestyle. Applied physiology, nutrition, and metabolism 35, 725-740 (2010).
6. Katzmarzyk, P. T. Physical activity, sedentary behavior, and health: paradigm paralysis or paradigm shift? Diabetes 59, 2717-2725 (2010).
7. Du, Y. et al. Trends in adherence to the Physical Activity Guidelines for Americans for aerobic activity and time spent on sedentary behavior among US adults, 2007 to 2016. JAMA Network Open 2, e197597-e197597 (2019).