By Sheri R. Colberg, PhD
For those of us who are reasonably fit and exercise regularly, it is hard for us to imagine that people who are currently sedentary, unfit, or overweight can benefit metabolically from doing something like simply taking breaks from sitting. However, the research in this area is now compellingly clear. Individuals with the most to gain can greatly affect their metabolic health by taking very small steps in the right direction with regard to their exercise habits.
For starters, we really need to emphasize getting up off the couch more. In newly-diagnosed adults with type 2 diabetes, ages 30-80, more time spent in sedentary pursuits is associated with a larger waist circumference, meaning that they have more deleterious visceral fat. (1) However, making small changes in daily activity levels, such as taking a five minute walking break every hour could benefit weight control or weight loss. An individual would theoretically expend an additional 24, 59 or 132 kilocalories during an 8-hour workday 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 for that whole time. (2) Therefore, simply taking breaks from sedentary time is a potential way to lose weight and prevent weight gain in the first place, and it likely would help prevent the onset of type 2 diabetes in the first place.
Moreover, a single bout of moderate exercise can have a more lasting effect on diabetes management than most people realize. For example, in a recent study, individuals with impaired glucose tolerance or type 2 diabetes engaged in a single session of either 30 minutes of moderate aerobic exercise or 45 minutes of moderate resistance training. (3) Amazingly, that single bout of either type of exercise substantially reduced the participants’ prevalence of hyperglycemia (defined as blood glucose levels >10 mmol/L) for the following 24 hours.
It’s not that all exercise has to be done that intensely either to have an effect. Individuals with type 2 diabetes who performed an isoenergetic bout of endurance-type exercise for 60 minutes at 35% of maximal workload (low-intensity) or 30 minutes at 70% (high-intensity) reduced their prevalence of hyperglycemia by 50% and 19% in the low- and high-intensity conditions, respectively, for 24 hours afterwards as well. (4) These results suggest that a single bout of low-intensity work may actually be more effective at lowering the prevalence of hyperglycemia throughout the subsequent 24-hour period than high-intensity work.
We usually tell people that doing daily exercise is better, but that may not be necessarily true either. When adults with type 2 diabetes either did no exercise or engaged in 60 minutes of moderate cycling exercise distributed either as a single session performed every other day or as 30 minutes of exercise performed daily and their blood glucose was monitored continuously for 48 hours, their prevalence of hyperglycemia was reduced from 32% of that period following no exercise to 24% over 48 hours following daily cycling or following cycling done every other day. Thus, it appears that as long as total caloric expenditure during exercise is matched, daily exercise can be done every other day instead and have the same glycemic results.
Since it’s so easy to have such a big impact, it’s about time we get everyone doing these activities to better manage their diabetes and their body weight. Time to stand up and walk around! Adult recess anyone?
- Cooper AR, Sebire S, Montgomery AA, Peters TJ, Sharp DJ, Jackson N, Fitzsimons K, Dayan CM, Andrews RC. Sedentary time, breaks in sedentary time and metabolic variables in people with newly diagnosed type 2 diabetes. Diabetologia. 2012; 55(3):589-99.
- Swartz AM, Squires L, Strath SJ. Energy expenditure of interruptions to sedentary behavior. Int J Behav Nutr Phys Act. 2011; 8:69.
- van Dijk JW, Manders RJ, Tummers K, Bonomi AG, Stehouwer CD, Hartgens F, van Loon LJ. Both resistance- and endurance-type exercise reduce the prevalence of hyperglycaemia in individuals with impaired glucose tolerance and in insulin-treated and non-insulin-treated type 2 diabetic patients. Diabetologia. 2011 Nov 29 [Epub ahead of print]
- Manders RJ, Van Dijk JW, van Loon LJ. Low-intensity exercise reduces the prevalence of hyperglycemia in type 2 diabetes. Med Sci Sports Exerc. 2010; 42(2):219-25.
- van Dijk JW, Tummers K, Stehouwer CD, Hartgens F, van Loon LJ. Exercise Therapy in Type 2 Diabetes: Is daily exercise required to optimize glycemic control? Diabetes Care. 2012 Mar 12. [Epub ahead of print]
Sign up for the Diabetes "Fit Brain, Fit Body!" fitness/lifestyle programs or for 5 free Healthy Living Reports at www.lifelongexercise.com, and access more articles and information at www.shericolberg.com. If you need tips for getting safely started on an exercise program, check out The 7 Step Diabetes Fitness Plan. For people with any type of diabetes who are already more active, consult the Diabetic Athlete’s Handbook.
Copyright © 2012 Diabetes In Control, Inc.