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diabetesmanagement

What Fitness Professionals Need to Know About Exercise and Diabetes

Are you working with any clients who have type 1 diabetes, type 2 diabetes, or even prediabetes? Well, you have a lot to learn if you don’t know the first thing about those conditions! There are over 100 million Americans currently have diabetes or prediabetes—some of them are, or will be, your clients.

Diabetes is a metabolic disorder that results in elevated levels of blood glucose (“blood sugar”) that can cause many health complications if not managed effectively. Although exercise is one of the three cornerstones of diabetes management, sometimes it can complicate keeping blood glucose levels under control, especially in people who have to replace the insulin that their bodies no longer make (or make enough of). How they respond to being active really depends on the type of exercise and diabetes.

In any case, on a basic level, it’s good to know more about how exercise affects people with diabetes. I have lived well with type 1 diabetes for nearly half a century at this point, and I have always known at some level that exercise did good things for my blood glucose, even before I had my first blood glucose meter (after going 18 years without one).  How could I tell without a meter to test my levels?  Honestly, it was because being active always made me feel better, physically and emotionally.

I earned a PhD in Exercise Physiology to better understand how exercising helped me. You don’t have to go that far with your education, but if you have diabetes or are going to work with clients or patients who have it, here are some basic things that you really need to know.

#1: Exercise can help erase your blood glucose “mistakes”

  • Exercise acts kind of like an extra dose of insulin.
  • At rest, insulin is the main mechanism your body has to get glucose into muscle cells.
  • During exercise, glucose goes your muscles without needing any insulin (via muscle contractions).
  • Being regularly active makes your muscles more sensitive to insulin, so it takes less to have the same blood glucose lowering effect when you eat during or after exercise.
  • What better way to help erase a little overeating of carbs (or some insulin resistance) than a moderate dose of exercise to lower your blood glucose?

#2: Exercise doesn’t always make your blood glucose go down

  • It doesn’t always make your blood glucose come down, at least not right away.
  • During intense exercise, the excess glucose-raising hormones your body releases can raise your blood glucose.
  • Over a longer period of time (2-3 hours), it usually comes back down, but who wants to wait that long?
  • If you take insulin, you’ll need to take less than normal to correct a post-workout high or your blood glucose will likely be crashing low a few hours later.
  • A cool-down of less intense exercise (like walking) can help bring it back to normal, so do an easy, active cool-down after intense workouts or activities.

#3: Your muscles are critical to managing your blood glucose levels

  • Exercise also helps you build and retain your muscle mass.
  • Muscles are the main place you store carbs after you eat them—like a gas tank.
  • Exercising helps use up stored carbs, but can also increase the size of the tank.
  • When you eat carbs post-exercise, they can easily go into storage with a little insulin.
  • Being sedentary keeps the tank full and makes you resistant to insulin.
  • Aging alone can cause you to lose muscle mass over time, but you can combat it to a certain extent by recruiting all of your muscle fibers regularly.
  • Resistance training and/or high-intensity intervals build muscle more because they
    recruit the faster fibers that you don’t use when walking or doing easier activities.

#4: Exercise is the best medicine there is

  • Use exercise to control stress and to stave off depression—with no bad side-effects!
  • It’s a natural antioxidant—more effective and better than supplements!
  • Being regularly active prevents all sorts of cancers.
  • If you’re active, you’ll likely feel better and look younger than you are (as long as you don’t exercise too much).
  • You’ll be even less likely to catch a cold if you exercise moderately and regularly.
  • Standing more, taking extra steps, and fidgeting even help—be active all day long, and don’t forget your daily dose of the best medicine there is!

Expand your Education to Work More Effectively with Diabetic or Pre-Diabetic Clients

Check out Dr. Colberg’s new 4 hour course with PTontheNet, Working with Clients with Diabetes or Prediabetes. With more knowledge about how to be active safely and effectively, you as their personal trainer can be a strong positive influence in getting diabetic or prediabetic individuals on the path to better health. Click here to learn more about the course!


Sheri R. Colberg, PhD, FACSM, is a Professor Emerita of Exercise Science at Old Dominion University and a former Adjunct Professor of Internal Medicine at Eastern Virginia Medical School. She is an internationally recognized authority on diabetes and exercise.

Glucometer, sport shoes, fresh apple and accessories for fitness

What You Need to Know about Exercise and Diabetes

Do you have type 1 diabetes, type 2 diabetes, or prediabetes? Then you need to know that exercise is a cornerstone in the management of all of these conditions, and it can benefit your health in so many ways.

diabetes oldSometimes, being active can actually make it more challenging for you to manage your blood glucose (“blood sugar”) levels, unless you learn more about its effects. I have always known at some level that exercise generally did good things for my blood glucose, even before I had my first blood glucose meter (after going 18 years without access to one).  How could I tell without a blood glucose meter?

Being active always made me feel better, physically and emotionally, so much so that I earned a PhD in Exercise Physiology to understand why. You don’t need to go that far with your education, but there are some basics about being physically active with diabetes or prediabetes that you really need to know.

Here are some things that I know about exercise now that I wish someone had told me years ago.

#1: Exercise can help erase your blood glucose “mistakes”

  • Exercise acts kind of like an extra dose of insulin.
  • At rest, insulin is the main mechanism your body has to get glucose into muscle cells.
  • During exercise, glucose goes your muscles without needing any insulin (via muscle contractions)
  • Being regularly active makes your muscles more sensitive to insulin, so it takes less to have the same effect when you eat during or after exercise.
  • What better way to help erase a little overeating of carbs (or some insulin resistance) than a moderate dose of exercise to lower your blood glucose?

#2: Exercise doesn’t always make your blood glucose go down

  • It doesn’t always make your blood glucose come down, at least not right away.
  • During intense exercise, the excess glucose-raising hormones your body releases can raise your blood glucose.
  • Glucometer, sport shoes, fresh apple and accessories for fitnessOver a longer period of time (2-3 hours), it usually comes back down, but who wants to wait that long?
  • If you take insulin, you’ll need to take less than normal to correct a post-workout high or your blood glucose will likely be crashing low a few hours later.
  • A cool-down of less intense exercise (like walking) can help bring it back to normal, so do an easy, active cool-down after intense workouts or activities.

#3: Your muscles are critical to managing your blood glucose levels

  • Exercise also helps you build and retain your muscle mass.
  • Muscles are the main place you store carbs after you eat them—like a gas tank.
  • Exercising helps use up stored carbs, but can also increase the size of the tank.
  • When you eat carbs post-exercise, they can easily go into storage with a little insulin.
  • Being sedentary keeps the tank full and makes you resistant to insulin.
  • Aging alone can cause you to lose muscle mass over time, but you can combat it to a certain extent by recruiting all of your muscle fibers regularly.
  • Resistance training and/or high-intensity intervals build muscle more because they recruit the faster fibers that you don’t use when walking or doing easier activities.

#4: Exercise is the best medicine there is

  • Use exercise to control stress and to stave off depression—with no bad side-effects!
  • It’s a natural antioxidant—more effective and better than supplements!
  • Being regularly active prevents all sorts of cancers.
  • If you’re active, you’ll likely feel better and look younger than you are (as long as you don’t exercise too much).
  • You’ll be even less likely to catch a cold if you exercise moderately and regularly.
  • Standing more, taking extra steps, and fidgeting even help—be active all day long, and don’t forget your daily dose of the best medicine there is!

For other tips on exercise and more, visit www.diabetesmotion.com or www.shericolberg.com. You can also find some exercise programs geared towards people with diabetes by visiting Diabetes Motion Academy (www.DMAcademy.com).


Sheri R. Colberg, PhD, FACSM, is a Professor Emerita of Exercise Science at Old Dominion University and a former Adjunct Professor of Internal Medicine at Eastern Virginia Medical School. She is an internationally recognized authority on diabetes and exercise.

sitting-sedentary

Is Sitting Really the New Smoking?

Make no mistake: sitting less time overall is a good idea for myriad health reasons, but is sitting as bad for you as some would suggest? Is it really the new smoking? In 2017 alone, a slew of new research studies has looked at various health detriments associated with prolonged sitting, even in adults who exercise regularly.

For adults with type 2 diabetes, bouts of either light walking or simple resistance activities benefit not only their glycemic responses to meals (4; 5), but also markers of cardiovascular risk. Both types of interrupting activities are associated with reductions in inflammatory lipids, increases in antioxidant capacity of other lipids, and changes in platelet activation (6).

What is good for one may not be as beneficial for all, though. For example, in adults with low levels of frailty, sedentary time is not predictive of mortality, regardless of physical activity level (1). Sitting more if you are already frail likely just increases frailty and mortality risk, which is not surprising. Along the same lines, being less fit matters in how you respond to breaking up sedentary time. Middle-aged adults with low levels of cardiorespiratory fitness gained the most metabolic benefit from breaking prolonged sitting with regular bouts of light walking, which included five minutes of light walking every 30 minutes over a 7-hour research period (2). If you’re already very fit, adding in some light walking breaks during the day is not going to have as much of an effect—again not surprising.

For in adolescents in school, reducing their sitting time (both in total time and length of bouts) has been shown to improve their blood lipid profiles and cognitive function. A “typical” day (65% of the time spent sitting with two sitting bouts >20 minutes) was compared with a simulated “reduced sitting” day (sitting 50% less with no bouts >20 minutes (3). Can teens stand to improve their health this week? Again, it cannot hurt to break up sedentary time, so why not do it? More recess breaks for teens would be good—and for everyone else for that matter.

All is not lost for people with limited mobility or no ability to engage in weight-bearing activities. Including short bouts of arm ergometry (five minutes of upper body work only every 30 minutes) during prolonged sitting attenuates postprandial glycemia (following two separate meals) when done by obese individuals at high risk of developing type 2 diabetes, even though they remain seated (7). People who cannot walk or stand can, therefore, break up their sedentary time in other ways that can also be metabolically beneficial.

As for other health benefits, breaking up sedentary time is associated with a lower risk of certain types of cancer. In a recent meta-analysis, prolonged television viewing, occupational sitting time, and total sitting time were all associated with increased risks of colorectal cancer in adults (8), which is the most common type after breast/prostate and lung cancers. That study reported a dose-response effect as well, suggesting that both prolonged total sitting time and greater total daily sitting time (2 hours) were associated with a significantly higher risk of colorectal cancer.

In summary, even just the most recent evidence is convincing enough that prolonged sitting is bad for you, and many more studies published similar results in prior years. Is sitting as bad as smoking, though? That remains to be proven. However, you really cannot argue with a recent international consensus statement on sedentary time in older people (9). It states, “Sedentary time is a modifiable determinant of poor health, and in older adults, reducing sedentary time may be an important first step in adopting and maintaining a more active lifestyle.” In fact, the best advice may simply be to consider the whole spectrum of physical activity, from sedentary behavior through to structured exercise (10). Putting yourself anywhere onto that spectrum is definitely better than sitting through the rest of your (shortened) life.

Reprinted with permission from Sheri Colberg.


Sheri R. Colberg, PhD, FACSM, is a Professor Emerita of Exercise Science at Old Dominion University and a former Adjunct Professor of Internal Medicine at Eastern Virginia Medical School. She is an internationally recognized authority on diabetes and exercise. As a leading expert on diabetes and exercise, Sheri has put her extensive knowledge to use in founding Diabetes Motion (diabetesmotion.com), a website providing practical guidance about being active with diabetes. She also founded Diabetes Motion Academy (dmacademy.com), offering training and continuing education to fitness professionals.

 

References cited:

  1. Theou O, Blodgett JM, Godin J, Rockwood K: Association between sedentary time and mortality across levels of frailty. CMAJ 2017;189:E1056-E1064. doi: 1010.1503/cmaj.161034.
  2. McCarthy M, Edwardson CL, Davies MJ, Henson J, Bodicoat DH, Khunti K, Dunstan DW, King JA, Yates T: Fitness Moderates Glycemic Responses to Sitting and Light Activity Breaks. Med Sci Sports Exerc 2017;8:0000000000001338
  3. Penning A, Okely AD, Trost SG, Salmon J, Cliff DP, Batterham M, Howard S, Parrish AM: Acute effects of reducing sitting time in adolescents: a randomized cross-over study. BMC Public Health 2017;17:657. doi: 610.1186/s12889-12017-14660-12886.
  4. Larsen RN, Dempsey PC, Dillon F, Grace M, Kingwell BA, Owen N, Dunstan DW: Does the type of activity “break” from prolonged sitting differentially impact on postprandial blood glucose reductions? An exploratory analysis. Appl Physiol Nutr Metab 2017;42:897-900. doi: 810.1139/apnm-2016-0642. Epub 2017 Mar 1124.
  5. Dempsey PC, Larsen RN, Sethi P, Sacre JW, Straznicky NE, Cohen ND, Cerin E, Lambert GW, Owen N, Kingwell BA, Dunstan DW: Benefits for type 2 diabetes of interrupting prolonged sitting with brief bouts of light walking or simple resistance activities. Diabetes Care 2016;39:964-972
  6. Grace MS, Dempsey PC, Sethi P, Mundra PA, Mellett NA, Weir JM, Owen N, Dunstan DW, Meikle PJ, Kingwell BA: Breaking Up Prolonged Sitting Alters the Postprandial Plasma Lipidomic Profile of Adults With Type 2 Diabetes. J Clin Endocrinol Metab 2017;102:1991-1999. doi: 1910.1210/jc.2016-3926.
  7. McCarthy M, Edwardson CL, Davies MJ, Henson J, Rowlands A, King JA, Bodicoat DH, Khunti K, Yates T: Breaking up sedentary time with seated upper body activity can regulate metabolic health in obese high-risk adults: A randomized crossover trial. Diabetes Obes Metab 2017;23:13016
  8. Ma P, Yao Y, Sun W, Dai S, Zhou C: Daily sedentary time and its association with risk for colorectal cancer in adults: A dose-response meta-analysis of prospective cohort studies. Medicine (Baltimore) 2017;96:e7049. doi: 7010.1097/MD.0000000000007049.
  9. Dogra S, Ashe MC, Biddle SJH, Brown WJ, Buman MP, Chastin S, Gardiner PA, Inoue S, Jefferis BJ, Oka K, Owen N, Sardinha LB, Skelton DA, Sugiyama T, Copeland JL: Sedentary time in older men and women: an international consensus statement and research priorities. Br J Sports Med 2017;19:2016-097209
  10. Dempsey PC, Grace MS, Dunstan DW: Adding exercise or subtracting sitting time for glycaemic control: where do we stand? Diabetologia 2017;60:390-394. doi: 310.1007/s00125-00016-04180-00124. Epub 02016 Dec 00112.