Why movement matters: The role of energy balance
Why movement matters: The role of energy balance
Thursday, July 26, 2018
/ By: Nicole Alfonsin, MPH, WELL AP
The public health community has focused tirelessly on combating physical inactivity and sedentariness which have risen over the last few decades and play a profound role in some of today’s most pervasive public health challenges. Our understanding of the interaction between physical activity, sedentary time and health is evolving, and today, we understand that all types of movement are important. Why? For many reasons, one of which is the impact of movement on energy balance.
What is energy balance?
Put most simply, energy balance is the relationship between energy in (intake) and energy out (expended). When energy intake exceeds energy expended, known as a positive energy imbalance, excess body fat develops. Excess body fat causes our cells to become “overfed” and disrupts metabolic processes leading to a cascade of physiological responses in the body that increase risk for heart disease, stroke, diabetes and some forms of cancer.[1,2,3] Achieving a healthy energy balance supports a healthy body composition which is known to reduce one’s risk for many chronic diseases. While energy balance is not the only mechanism through which we can prevent and combat chronic diseases, it plays an important and deeply biological role in our health and well-being.
Of the factors that contribute to total daily energy expenditure, energy expended from physical activity and movement is most variable. That is, we have the most control over our activity levels which result in changes to our overall energy expenditure. The recent shift from the “Fitness” concept title to the “Movement” concept title in WELL v2™ pilot reflects a more nuanced understanding of health contributions that come from all types of movement not simply those that increase various components of physical fitness (e.g., cardiorespiratory fitness, strength, agility, flexibility). It is not to say that all forms of movement are equal, but all forms are important; especially when it comes to energy balance.
How do different types of movement contribute to energy expenditure?
With a better understanding of how different types of movement impact energy expenditure, we can begin to identify how to best integrate and prioritize different types of movement into our daily lives in order to achieve better energy balance. Metabolic equivalents (METs) help us understand how different types of movement will contribute to total daily energy expenditure based on the oxygen required to perform a given activity. Once we know the oxygen requirements of an activity we can then determine how much energy (in kilocalories (kcals)) the body will expend during that activity. One MET is equivalent to 3.5 milliliters (mLs) of oxygen per kilogram (kg) of body weight. For the average person, one MET translates to about 1.2 kcals expended per minute. This level of intensity (one MET) captures resting activities (e.g., laying down). Activities are very commonly classified by their intensity: light (>1.6 to 2.9 METs), moderate (>3 to 5.9 METs) or vigorous (>6 METs). Fortunately, researchers have made it easy to compare the energy cost of different types of movement, as MET values have been determined for nearly any activity one can think of and can be found in the Compendium of Physical Activities.
With a better understanding of the MET, you could conclude that a single instance of vigorous-intensity activity will increase energy expenditure and you’d be correct. However, there are multiple ways we can leverage what we know about the MET to achieve better energy balance. For example, one could 1) increase how often you walk throughout the day (frequency); 2) increase the length of time that you walk (duration); or 3) begin walking briskly uphill or running instead of walking (intensity). Whether one chooses to increase frequency, duration or intensity of movement, it will result in greater energy expenditure and contribute to an increase in total daily energy expenditure.
Energy balance and the mission of the WELL v2 Movement concept.
The mission of the Movement concept in WELL v2 is to create and enhance opportunities for movement in all aspects of life. It looks for ways to not only help us move more, but also replace sedentary activities with more active ones. In terms of energy balance, these goals aim to maximize energy expenditure throughout the day by creating spaces and providing programs and policies that invite more movement. When you reduce sitting time by using your standing desk, you are increasing movement. When you skip the online chat and instead walk to your teammate’s desk to chat about an idea, you are increasing movement and reaching towards better energy balance. It is important to understand that many forms of movement contribute to total daily energy expenditure, and that projects who seek to have the most impact for the health and well-being of their occupants should seek to create spaces that invite sporadic, small, frequent opportunities for movement and also provide opportunities for intentional physical activity and exercise. Collectively, these strategies help all of us who live, learn and work in buildings.
To learn more about movement and energy balance, their relationship to health and buildings and strategies to promote active lifestyles, check out the Movement concept in WELL v2.
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Caballero, B. (2007). The Global Epidemic of Obesity: An Overview. Epidemiologic Reviews, 29, 1-5. Doi: https://www.ncbi.nlm.nih.gov/pubmed/17569676
Kyu HH, Bachman VF, Alexander LT, et al. Physical activity and risk of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke events: systematic review and dose-response meta-analysis for the Global Burden of Disease Study 2013. BMJ. 2016;354. http://www.bmj.com/content/354/bmj.i3857.abstract.
Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett Jr DR, Tudor-Locke C, Greer JL, Vezina J, Whitt-Glover MC, Leon AS. 2011 Compendium of Physical Activities: a second update of codes and MET values. Medicine and Science in Sports and Exercise, 2011;43(8):1575-1581. https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxjb21wZW5kaXVtb2ZwaHlzaWNhbGFjdGl2aXRpZXN8Z3g6MjgyY2EyMzQzNWFlN2Q3OA