Category Archives: Exercise is medicine

Staying Active with Aging Joints and Diabetes

Using bandsWithout properly functioning joints, our bodies would be unable to bend, flex, or even move. A joint is wherever two bones come together, held in place by tendons that cross the joint and attach muscles to a bone on the other side and ligaments that attach to bones on both sides of the joint to stabilize it. The ends of the bones are covered with cartilage, a white substance. Specialized cells there called chondrocytes produce large amounts of an extracellular matrix composed of collagen fibers, proteoglycan, elastin fibers, and water. Tendons and ligaments are also made up of primarily of collagen.

Joints can be damaged, however, making movement more difficult or painful. Joint cartilage can be damaged by acute injuries (i.e., ankle sprain, tendon or ligament tears) or overuse (related to repetition of joint movements and wear-and-tear over time). Damage to the thin cartilage layer covering the ends of the bones is not repaired by the body easily or well, mainly because cartilage lacks its own blood supply.

Aging alone can cause you to lose some loss of this articular cartilage layer in knee, hip, and other joints—leading to osteoarthritis and joint pain—but having diabetes also potentially speeds up damage to joints. Although everyone gets stiffer joints with aging, diabetes accelerates the usual loss of flexibility by changing the structure of collagen in the joints, tendons, and ligaments. In short, glucose “sticking” to joint surfaces and collagen makes people with diabetes more prone to overuse injuries like tendinitis and frozen shoulder (1; 2). It may also take longer for their joint injuries to heal properly, especially if blood glucose levels are not managed effectively. What’s more, having reduced motion around joints increases the likelihood of injuries, falls, and self-imposed physical inactivity due to fear of falling.

Reduced flexibility limits movement around joints, increases the likelihood of orthopedic injuries, and presents a greater risk of joint-related problems often associated with diabetes, such as diabetic frozen shoulder, tendinitis, trigger finger, and carpal tunnel syndrome. These joint issues can come on with no warning and for no apparent reason, even if an individual exercises regularly and moderately, and they may recur more easily as well (3). It is not always just due to diabetes, though, since older adults without diabetes experience inflamed joints more readily than when they were younger.

So what can you do to keep your joints mobile if you’re aging (as we all are) and have diabetes? Regular stretching to keep full motion around joints can help prevent some of these problems, and also include specific resistance exercises that strengthen the muscles surrounding affected joints. Vary activities to stress joints differently each day. Overuse injuries occur following excessive use the same joints and muscle in a similar way over an extended period of weeks or months, or they can result from doing too much too soon.

Doing moderate aerobic activity that is weight-bearing (like walking) will actually improve arthritis pain in hips and knees (4). People can also try non-weight-bearing activities, such as aquatic activities that allow joints to be moved more fluidly. Swimming and aquatic classes (like water aerobics) in either shallow or deep water are both appropriate and challenging activities to improve joint mobility, overall strength, and aerobic fitness. Walking in a pool (with or without a flotation belt around the waist), recumbent stationary cycling, upper-body exercises, seated aerobic workouts, and resistance activities will give you additional options to try.

Finally, managing blood glucose levels effectively is also important to limit changed to collagen structures related to hyperglycemia. Losing excess weight and keeping body weight lower will decrease the risk for excessive stress on joints that can lead to lower body joint osteoarthritis (5). Simply staying as active as possible is also critical to allowing your joints to age well, but remember to rest inflamed joints properly to give them a chance to heal properly. You may have to try some new activities as you age to work around your joint limitations, but a side benefit is that you may find some of them to be enjoyable!

References:

  1. Abate M, Schiavone C, Pelotti P, Salini V: Limited joint mobility in diabetes and ageing: Recent advances in pathogenesis and therapy. Int J Immunopathol Pharmacol 2011;23:997-1003
  2. Ranger TA, Wong AM, Cook JL, Gaida JE: Is there an association between tendinopathy and diabetes mellitus? A systematic review with meta-analysis. Br J Sports Med 2015;
  3. Rozental TD, Zurakowski D, Blazar PE: Trigger finger: Prognostic indicators of recurrence following corticosteroid injection. J Bone Joint Surg Am 2008;90:1665-1672
  4. Rogers LQ, Macera CA, Hootman JM, Ainsworth BE, Blairi SN: The association between joint stress from physical activity and self-reported osteoarthritis: An analysis of the Cooper Clinic data. Osteoarthritis Cartilage 2002;10:617-622
  5. Magrans-Courtney T, Wilborn C, Rasmussen C, Ferreira M, Greenwood L, Campbell B, Kerksick CM, Nassar E, Li R, Iosia M, Cooke M, Dugan K, Willoughby D, Soliah L, Kreider RB: Effects of diet type and supplementation of glucosamine, chondroitin, and msm on body composition, functional status, and markers of health in women with knee osteoarthritis initiating a resistance-based exercise and weight loss program. J Int Soc Sports Nutr 2011;8:8

Take Back Your Steps!

ADA stairs pictureIt has long been known that regular physical activity is essential for good health. Even Well over 2,000 years ago, Hippocrates (460-370 BC) noted, “Eating alone will not keep man well; he must also take exercise. For food and exercise work together to produce health.” Why, then, is it so hard for us to embrace this concept of being active now?

The main reason that comes to mind is that doing structured exercise takes time, and we all seem to have too little of that nowadays. The only answer to having limited time is my new motto for everyone: “Take back your steps.”

What do I mean by that? A prime example occurs whenever I attend large conventions that involve escalators vs. stairs. I can’t tell you how many times I have come out of a large lecture hall and seen a long line of people (health care professionals at that) waiting to take the escalator that will allow them to ride up to the next floor—even when the stairs right next to the escalators are completely empty and readily available.

It’s time for all of us to start focusing more on doing “unstructured” activities like taking the stairs and walking more. You can always make time in your day to take a few extra steps here and there, and by the end of the day they can add up to a large number. They can even mostly replace your need to engage in more formal exercise programs for which too many people have excuses to not do regularly.

Sure, it’s still beneficial to get in your 30- to 60-minute bouts of aerobic training, and doing some resistance training every week—even if you just do exercises at home that use your own body weight as resistance—is critical to living long and well (and independently).  Arguably, though, the best thing you can do for your overall health and wellbeing at this point is to simply move more all day long, however you can.

Ask your boss for a standing desk, stand up during phone calls, stand up during meetings instead of sitting down the whole time, get up and walk around at least once an hour (to break up your sedentary time), and do resistance exercises while sitting in your chair or driving in your car. All these things simply involve a slight mental adjustment to make them part of your new activity behaviors.

The joy of taking back your steps is that everyone can do it! (Even if you can’t walk, you can do it metaphorically by being more active doing seated exercises.) Who knows?  You may start a trend among your family, friends, and coworkers. At a minimum, you’ll feel more energetic every day instead of tired all the time.

What are you waiting for? Get up and take back your steps today…and every day for the rest of your long and healthy life!

What Affects How Your Insulin Works?

Delaine Wright (T1D) 1There’s nothing worse than doing everything right (or so you think) and having your blood glucose levels running high inexplicably. The problem may be that many different factors can affect your insulin action (whether it’s insulin your body releases or insulin you inject or pump), and you may or may not be controlling for all of them equally well.

What we do know is that most athletic individuals have lower levels of insulin and require less insulin release for carbohydrate and other food intake, meaning that their bodies are very sensitive to insulin. Having low fasting insulin levels (assuming it is not due to a deficiency) is associated with greater longevity, as demonstrated by the fact that most 100-year-olds without diabetes exhibit this trait. Keeping insulin needs lower also reduces your risk for heart disease, high blood pressure, certain cancers, and more.

So what can you do to keep your insulin action high? Almost any type of physical training can make your insulin work better. Resistance training results in enhancements in your muscle mass, allowing for greater overall glucose uptake. Aerobic training generally does not increase muscle mass as much, but that type of activity can enhance muscular uptake of blood glucose.

The effects of aerobic exercise on insulin action usually start to decline within 1-2 days, however, and regular aerobic activity is essential to keeping it higher. Increasing your overall muscle mass may have a more lasting effect by allowing for greater glucose storage in muscle (an insulin-sensitive tissue) and increasing the total amount of glucose you can dispose of through glycogen storage. Muscles have a limit to how much they can store, and having more muscle mass results in a greater potential storage capacity.

Myriad factors can improve your body’s insulin action and making control blood glucose levels easier with less insulin. Don’t try just adding some or more exercise in. For optimal results, try to improve your body’s insulin action by several of these means as their effects are likely to add together to result in a greater overall effect.

Factors That Can Improve Insulin Action:

  • Regular aerobic and resistance exercise
  • Muscle mass gain
  • Loss of body fat—particularly intra-abdominal (visceral) fat, extra fat stored in the liver, and possibly some of the excess fat in muscles
  • Improved blood glucose control (and avoidance of highs and lows)
  • Reduced levels of circulating triglycerides and free fatty acids (fats in blood)
  • Reduction in low-level, systemic inflammation (with physical activity and antioxidants)
  • More effective leptin action (hormone released by fat), causing reduced food intake
  • Reduction in mental (anxiety, depression) and/or physical (illness, etc.) stressors
  • Control of physical (illness, infections, severe muscle soreness, etc.) stressors
  • Decrease in circulating levels of cortisol (released by physical and mental stressors)
  • Increased testosterone levels in men
  • Intake of more dietary fiber, less trans fat, and fewer highly refined foods
  • Daily consumption of a healthy breakfast
  • Adequate dietary intake of key vitamins and minerals, such as magnesium
  • Lower caffeine intake
  • Adequate sleep (seven to eight hours a night for most adults)
  • Effective treatment of sleep apnea
  • Use of insulin-sensitizing oral medications (like Avandia or Actos)

Are You an Exercise Non-Responder?

Roger Hanney (T1D)When researchers have done studies on adults with type 2 diabetes, although the participants as a whole have a positive average response to exercise training, as many as 15 to 20 percent of type 2 exercisers have been found to be “non-responders” (1). These are individuals who appear to be resistant to the beneficial effects of exercise training of all types because exercise training for them fails to improve their A1C (overall blood glucose control), body fat, body mass index, or other metabolic measures. But are there really exercise non-responders? And, if so, are you one of them?

Some researchers have blamed the exercise “non-response” observed in a minority of research subjects on inheriting bad genes. However, a large part of the data that these scientists used to “prove” their case came from animal research. For example, successive generations of rats have been bred until they had either a very high aerobic capacity or a low one, and the researchers then applied their findings that those animals with a low aerobic capacity don’t gain the same metabolic benefits directly to humans.

People are far from being similar to lab rats, though! We’re much more genetically diverse, and our muscles can improve their aerobic capacity with training, regardless of what genes we inherited from our parents (2). In fact, a recent review of 18 training studies concluded that normal training adaptations to aerobic exercise are possible in adults with type 2 diabetes (3), again suggesting the environment is a more viable explanation for those few who don’t respond like everyone else.

What are these environmental factors? For starters, a big issue with human aerobic training is that not all individuals in exercise studies end up training similarly, despite the good intentions of the researchers. I know from training hundreds of research subjects over the years that many older people don’t push themselves as hard as they could when they’re doing the initial exercise test (especially when riding a cycle that makes their legs hurt), and their training protocol is then set up based on a lower-than-actual maximal capacity. So, they may simply not be doing as much total training or expending as many calories during exercise as others in the study.

Many older adults with diabetes also have joint issues or health problems that limit their ability to exercise, including excess body fat, high blood pressure, or nerve damage in their feet. What’s more, what people eat is seldom controlled well in exercise studies, and taking in excess food can override the benefits of exercise, including limiting how long or high insulin action is elevated and blood glucose control after workouts (4). In other words, it’s entirely possible to negate the effects of the last bout of exercise and diminish its acute (and chronic) metabolic benefits by overfeeding.

Simply being less active during the rest of the day can also impact whether you experience the expected results of doing the training. Not surprisingly, people who are more active all day long and not just during training sessions fare better as far as their metabolic health is concerned, even when exercise training is the same for all participants in a study (5).

Even the medications you take can limit your responses to doing exercise training. The most commonly prescribed medication for type 2 diabetes is metformin, and taking metformin can blunt your normal metabolic response to exercise training (6). Taking statins to lower your blood cholesterol can cause some muscular problems that may limit your ability to exercise, as can some other medications commonly prescribed for other health problems.

Even if it’s not the environment that is holding you back and you do have some genetic traits that may limit your exercise response, that certainly doesn’t mean that you won’t gain a lot of other health benefits—both physical and mental—from being more physically active. There really is no evidence that the potential to response to exercise training is limited if you have type 2 diabetes, type 1 diabetes, prediabetes, or obesity; in fact, even breaking up prolonged sitting time has measurable metabolic benefits for everyone (7). So, get up and go be active doing whatever you enjoy the most—and be as active as you possibly can all day long. Your body will thank you for it!

References Cited:

  • Stephens NA, Sparks LM: Resistance to the beneficial effects of exercise in type 2 diabetes: Are some individuals programmed to fail? J Clin Endocrinol Metab 2015;100(1):43-52
  • Pruchnic R, Katsiaras A, He J, Kelley DE, Winters C, Goodpaster BH: Exercise training increases intramyocellular lipid and oxidative capacity in older adults. Am J Physiol Endocrinol Metab 2004;287:E857-862
  • Wang Y, Simar D, Fiatarone Singh MA: Adaptations to exercise training within skeletal muscle in adults with type 2 diabetes or impaired glucose tolerance: a systematic review. Diabetes Metab Res Rev 2009;25:13-40
  • Hagobian TA, Braun B: Interactions between energy surplus and short-term exercise on glucose and insulin responses in healthy people with induced, mild insulin insensitivity. Metabolism 2006;55:402-408
  • Manthou E, Gill JM, Wright A, Malkova D: Behavioral compensatory adjustments to exercise training in overweight women. Med Sci Sports Exerc. 2010;42(6):1121-8
  • Braun B, Eze P, Stephens BR, et al.: Impact of metformin on peak aerobic capacity. Appl Physiol Nutr Metab 2008;33:61-7
  • Dunstan DW, Kingwell BA, Larsen R, et al.: Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses. Diabetes Care 2012;35:976-983

What You Need to Know about Diabetes and Exercise

Joel Livesey (T1D)Here are important things everyone needs to know about exercise and diabetes:

Many times, exercise can virtually erase your blood glucose mistakes. It acts as an extra dose of insulin by getting the glucose out of your blood and into your muscles without insulin (through an insulin-independent mechanism related to muscle contractions themselves). When you’re not active, your body needs insulin to stimulate that uptake. Being regularly active makes your muscles more sensitive to any insulin in your body as well, so it takes less to get the job done. What better way to help erase a little overeating of carbs (or a slight lack of insulin or insulin resistance) than a moderate dose of exercise?

Exercise doesn’t always make your blood glucose come down, at least not right away. When you do intense exercise, glucose-raising hormones (like adrenaline and glucagon) can actually raise your blood glucose instead, albeit usually only temporarily. This phenomenon is true for people with any type of diabetes and even for anyone without diabetes. However, even if a workout raises it in the short run, over a longer period of time (2-3 hours), the residual effects of the exercise will bring your blood glucose back down while you’re replacing the carbs in your muscles. If you take insulin, be careful to take less than normal to correct a post-workout high or your blood glucose will likely be crashing low a few hours later. If you don’t take insulin, give it some time to come back down or do a cool-down with less intense exercise (like less-than-brisk walking) to help bring it back to normal.

How much muscle you have really makes a big difference to your blood glucose control (see prior blog on this topic). Exercise helps you build and retain your muscle mass, which is the main place you store carbs after you eat them. Almost any type of exercise uses up some of your muscle glycogen stores, but if you don’t exercise regularly, your muscles remain packed with it. There is a maximal amount that fits in muscles, which is why building up your muscle mass helps with being able to handle the carbs you eat more effectively. Your liver stores some glucose as glycogen, but not that much relative to your muscles’ total storage capacity. Being sedentary ensures that no amount of insulin is going to be able stimulate more blood glucose uptake into your muscles. Without regular exercise to use up some of that glycogen, you really have nowhere to store carbs, so your blood glucose goes up and some of the excess gets turned into body fat instead. Doing resistance or heavier aerobic training is critical to maintaining the muscle mass you have and offsetting the effects of getting older as much as possible.

People with naturally lower levels of insulin generally live longer (think of centenarians and elite athletes, both of whom have low insulin levels). Exercise helps you keep your insulin needs low, which makes it easier to either make enough of your own or get by with much smaller doses (resulting in less of a margin for big errors in dosing). Plus, It’s really a lot harder to lose body fat if your insulin levels are high or you take large doses because insulin promotes fat storage from excess blood glucose. Both the last time you exercised and how regularly you’re active have an impact on the insulin sensitivity of your muscles, so aim to exercise as least every other day (although daily is likely better) and keep all those muscle fibers you have by using them regularly.

Diabetes aside, exercise is about the best medicine that there is for so many other health conditions.  Being active is one of the best ways to control emotional stress and to stave off depression—far better than antidepressant medications and with no bad side-effects! What’s more, exercise naturally bestows your body with antioxidant effect, which is why regular exercisers are less likely to develop most types of cancer. They also generally feel and act younger than their chronological age and are less likely to even get a cold if doing moderate amounts of regular exercise.

Finally, there are many different ways to exercise, including standing up more, taking extra steps during the day, fidgeting, and just generally being on the move whenever and wherever possible. Knowing that hopefully takes away all of your excuses for not being more active. If you can’t get in a “planned” workout on any given day, you can certainly add in more steps or other activity all day long instead (or do it in addition to your usual exercise). Every bit of movement you do during the day counts, so fidget away as part of your daily dose of exercise!

Diabetes Rising: What Can We Do to Stop It Before It’s Too Late?

China DM and prediabetes

As if the predictions of diabetes to come were not already grim enough, a new report released by the Centers for Disease Control and Prevention now predicted that one in three American adults may have diabetes by 2050, with the number of diabetes patients projected to double or triple over the next 40 years. While the report blames the predicted increase primarily on an aging population, more members of high-risk minority groups, and longer survival in people who already have diabetes, my perspective on the cause of this epidemic is somewhat different.

Let me address these three points in order. Many chronic diseases get blamed on aging when in fact the real culprit is lifestyle choices. With diabetes in particular, the amount of metabolically active muscle mass you retain as you age has a huge impact on insulin action, given that skeletal muscles are the primary storage site for carbohydrates. If you exercise regularly and recruit all of your muscle fibers with intense or vigorous activities, you will lose less muscle mass and retain a much higher level of insulin sensitivity. If you also eat fewer refined carbohydrates that are quickly converted into blood glucose and that are lacking in fiber and essential anti-diabetic nutrients (like magnesium and vitamin D), your insulin action will remain higher as you age.

As for an increase in high-risk minority groups being the cause, let’s re-examine the case of two biologically related minority groups with completely different rates of diabetes. The Pima Native Americans of Arizona have an extremely high incidence of obesity, insulin resistance, and type 2 diabetes, with more than half of all Pima adults 35 years and older with type 2 diabetes. However, another group of Pimas from whom the Arizona group descended was discovered in Mexico, and despite sharing the same gene pool, these two groups differ dramatically in their levels of body fat. Here again, lifestyles make a difference: the Mexican Pimas are physically active farmers who eat a traditional diet of natural foods such as wheat, squash, beans, cactus buds, squawfish, and jackrabbit, while the Arizona Pimas eat highly refined, nutrient-poor foods and have a sedentary lifestyle. It should come as no surprise that the Arizona Pimas are the only ones who have type 2 diabetes.

Finally, just the fact that some people are surviving longer with diabetes (and adding to the growing number of cases) is not in itself cause for concern. Individuals with good self-care practices and adequate diabetes control are likely not developing diabetes-related health problems at the same rate as those with less healthy lifestyles and inadequate glycemic control.

What can we do to stop the rising number of cases? For starters, we have to address the causes on the personal and community levels, along with as a nation. Some small steps are being taken in that direction with the CDC’s launch of the Diabetes Prevention Program through the Y and others. Really, the bigger problem to address is that despite our knowledge of what we should be doing, most Americans are not following through on this. What we have is not a lack of motivation; rather, it is a behavior problem that is both personal and society-wide.

For example, for their safety, we strap our toddlers into strollers or keep them sitting in front of the television instead of walking whenever they can or playing outside. We keep our kids sitting and motionless during most of the school day, and then we feed them an excess of unhealthy calories for lunches and snacks. We adults stand and wait for elevators when we could take the stairs, and we stand on escalators instead of walking up and down them (even at the American Diabetes Association meetings, where everyone is supposed to know better).

What is it going to take to turn around our lifestyles for the better on a wide scale? In my opinion, we need to involve money. If all of us could have more change in our pockets if we choose a healthy lifestyle, the habits of Americans will likely finally start to change for the better. Let’s start by trying to get more health insurers interested in lowering health insurance rates for individuals with healthy behaviors, and let’s get more businesses interested in doing the same for their employees. Hopefully, we will not have to take as drastic a stand as they have in Japan, where companies are being fined based on the number of employees they have with waistlines above 32 inches. But, at this point, we have to start taking more steps in that direction instead of just wringing our hands and worrying about what’s to come (without our intervention).

Small changes can make a big difference in the health and waistlines of Americans. Just standing more each day burns calories and tips the scales in the direction of weight loss instead of further weight gain. Eating a salad with your dinner substantially lowers calorie intake at that meal, and simply taking in 50 calories fewer than you need a day can result in a five-pound loss of fat weight in a year, without any effort.

Take a stand yourself today by becoming a role model of a healthier lifestyle for everyone that you come in contact with. Use social networks to get others involved. Put your money where your mouth is. Let’s all get moving more, eating better, and staying thinner and healthier—starting today!

For Many, Doing So Little Can Have a Big Effect

Chelsea Brown (T1D) stretchingFor 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?

References Cited:

1. 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.

2. Swartz AM, Squires L, Strath SJ. Energy expenditure of interruptions to sedentary behavior. Int J Behav Nutr Phys Act. 2011; 8:69.

3. 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. 2012;55(5):1273-82.

4. 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.

5. 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;35(5):948-54.