By Sheri Colberg, PhD
Individuals with diabetes are frequently deconditioned and live a sedentary lifestyle. The good news is that people starting out on the lowest end of the fitness scale have the most to gain from adding in very little physical activity.
The first major step in becoming regularly physically active is to incorporate more activities of daily living and other unstructured physical activity into their lifestyle.1,2 Standing up and moving around more can by themselves lower metabolic risk, and health benefits result from concurrently reducing total time engaged in sedentary pursuits and interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in adults who are already physically active.3,4
Making small changes in daily activity levels, such as taking a five-minute walking break every hour, also likely benefits weight management or loss. Theoretically, during an 8-hour workday, an individual can expend an extra 24, 59 or 132 Calories by simply getting up and walking around at a normal, self-selected pace for one, two, or five minutes every hour, respectively, compared with sitting.5 Even modest amounts of exercise in the absence of weight loss benefit glucose and fat metabolism in previously sedentary, middle-aged adults.6 Therefore, simply taking breaks from sedentary time is a potential way to lose weight and prevent weight gain, and it may help prevent the onset of type 2 diabetes in the first place.
Sedentary time predicts higher levels of fasting insulin independent of the amount of time spent doing moderate- and vigorous-intensity activity levels in people without diabetes.7 For those with diabetes, inclusion of more daily, unstructured physical activity is likely to bestow even greater health and glycemic benefits. Taking more frequent breaks from sedentary time has been shown to improve waist circumference, body mass index, triglyceride levels, and 2-hour postmeal plasma glucose levels, again accentuating the importance of avoiding prolonged uninterrupted periods of sedentary (primarily sitting) time.8 Frequent breaks from sitting may also assist in controlling postprandial spikes that have been found to be prevalent throughout the day in individuals with type 2 diabetes, even in those with an A1c level well below 7.0%.9
In newly-diagnosed adults with type 2 diabetes (ages 30-80), more time spent in sedentary pursuits has been associated with a larger waist circumference,10 likely reflective of a greater amount of deleterious visceral fat.11 However, energy expended during activities of daily living can create a large daily caloric deficit to prevent excessive weight gain and facilitate body weight and blood glucose management.2,12
Standing counts as unstructured activity. In an observational study, obese individuals sat for about 2.5 hours more and walked an average of 3.5 miles less per day than their lean counterparts.2 Furthermore, most of the greater activity done by lean participants resulted from walks of short-duration ( less than 15 minutes) and low-velocity (about one mile per hour). Thus, how long individuals spend sitting each day and whether they move at all during periods of prolonged inactivity is critical in determining metabolic health and diabetes management.
Of course, progressing from taking more frequent breaks in sedentary time to moving more all day long and engaging in more structured physical activities will likely bestow additional health benefits. Sedentary individuals have to start somewhere, though, and just getting them up on their feet can move them well out of the highest health risk category without their ever having to break a sweat. A good rule of thumb is to never sit more than 30 minutes continuously without standing up and taking a break — or even better, walking around for a few minutes to minimize the negative metabolic effects of prolonged sitting.
- Johannsen DL, Welk GJ, Sharp RL, Flakoll PJ. Differences in daily energy expenditure in lean and obese women: the role of posture allocation. Obesity (Silver Spring) 2008;16:34-9.
- Levine JA, Lanningham-Foster LM, McCrady SK, et al. Interindividual variation in posture allocation: possible role in human obesity. Science 2005;307:584-6.
- Dunstan DW, Kingwell BA, Larsen R, et al. Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses. Diabetes Care 2012;35:976-83.
- Garber CE, Blissmer B, Deschenes MR, et al. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc 2011;43:1334-59.
- Swartz AM, Squires L, Strath SJ. Energy expenditure of interruptions to sedentary behavior. Int J Behav Nutr Phys Act 2011;8:69.
- Duncan GE, Perri MG, Theriaque DW, Hutson AD, Eckel RH, Stacpoole PW. Exercise training, without weight loss, increases insulin sensitivity and postheparin plasma lipase activity in previously sedentary adults. Diabetes Care 2003;26:557-62.
- Helmerhorst HJ, Wijndaele K, Brage S, Wareham NJ, Ekelund U. Objectively measured sedentary time may predict insulin resistance independent of moderate- and vigorous-intensity physical activity. Diabetes 2009;58:1776-9.
- Healy GN, Dunstan DW, Salmon J, et al. Breaks in sedentary time: beneficial associations with metabolic risk. Diabetes Care 2008;31:661-6.
- van Dijk JW, Manders RJ, Hartgens F, Stehouwer CD, Praet SF, van Loon LJ. Postprandial hyperglycemia is highly prevalent throughout the day in type 2 diabetes patients. Diabetes Res Clin Pract 2011;93:31-7.
- Cooper AR, Sebire S, Montgomery AA, et al. Sedentary time, breaks in sedentary time and metabolic variables in people with newly diagnosed type 2 diabetes. Diabetologia 2012;55:589-99.
- Amati F, Pennant M, Azuma K, et al. Lower Thigh Subcutaneous and Higher Visceral Abdominal Adipose Tissue Content Both Contribute to Insulin Resistance. Obesity (Silver Spring) 2012.
- Levine JA, McCrady SK, Lanningham-Foster LM, Kane PH, Foster RC, Manohar CU. The role of free-living daily walking in human weight gain and obesity. Diabetes 2008;57:548-54.
Copyright © 2012 Diabetes In Control, Inc.