Athletic Injuries and Aging—It Isn’t for Sissies

I recently overheard an older woman in my local public pool locker room recounting a story to a friend about developing plantar fasciitis, a common foot arch overuse injury. To my knowledge, she did not have diabetes (which could have put her at higher risk for developing any and all overuse and joint injuries), but she looked to be in her late 60s or early 70s.

Her story was that her foot problems had come on suddenly, and the only thing she had done differently was walk on the beach and go up and down about 150 steps to access the sand. She had been a bit sore in her leg and butt muscles the day after the beach walk, and then her plantar fasciitis came on shortly thereafter. She told her friend that she and her husband cycle three days a week and swim on the other days, so they are regularly active but just hadn’t been walking the beach or the steps to reach it for about six months.

Her exasperated comment was, “So, now I’m at the age where I’m getting injured from just walking?”

Her story resonated with me, given my own recent experiences with having various overuse injuries that come out of seemingly nowhere. This past weekend, I did the same step and beach walk as that older woman (who has at least a decade on me). The walk was only about 3 miles at a normal pace, but the sand was fairly slanted due to the tides and our timing. The next day when my husband and I went for another walk on regular level surfaces, my left hip joint was hurting and the pain has persisted for a couple days. Yesterday, I tried doing a hip abductor resistance training machine and could barely move any weight with my left side—all from just beach walking!

Both of our stories just go to show you that training is very specific for the joints and muscles used and the manner in which they are worked. Cycling does not train you for swimming, and even walking on flat surfaces (which I do regularly) does not stress your joints and muscles the same way as walking on a slanted beach (which I had not done for at least 5 months).

Generally, overuse injuries are caused by repetitive microtrauma that leads to inflammation and/or local tissue damage. Unfortunately, this damage can result in overuse conditions like tendinitis or tendinosis, stress fracture, synovitis, entrapment neuropathies, ligament strains, or myositis.

When are you most likely to develop such injuries? They’re more common whenever you change the mode, intensity, or duration of your exercise training. Changing your normal workouts causes your body to respond to the repetitive overload on tissues that are trying to adapt to the new or increased demands. When there is a mismatch between overload and recovery, you can end up with tissue breakdown at the cellular level, which can lead to an acute injury or an overuse one.

What can you do to combat getting such overuse injuries, especially when you’re busy and already fitting in as much activity on a daily/weekly basis as you can? Here are a few suggestions:

• Ease into different and/or new activities slowly and don’t overdo it when you start out until your body has time to adapt and adjust.
• Give your irritated joints time to heal before you try the aggravating activity again (in other words, don’t add insult to injury by trying them again until the pain is better).
• Work on getting and maintaining full motion around the joints you tend to aggravate as their flexibility is important to avoid injuries.
• Incorporate exercises into your resistance training routine that strengthen all the muscles around your joints to balance them out, especially any joints you have injured previously.
• Work on your form or mitigate other aggravating factors—such as getting newer or different shoes, especially if you have a lot of miles on your current pair or need a different type to walk on the beach.

As they always say, aging isn’t for sissies. But I also always add, “But it beat the alternative.” Stay active, stay well, and live a long and healthy (and hopefully mostly injury-free) life.

Variety Is the Spice of Life—and of Physical Activity

I am a long-time believer in the benefits of cross-training when it comes to physical activity. Cross-training means varying your training mode from day to day: for example, on Monday, Wednesday, and Friday, you may do brisk walking and another aerobic exercise (like cycling, rowing, or swimming) on alternate days or resistance training. Doing a variety of activities not only helps you prevent overuse injuries (1), but also can be more motivating.

Since most of the physical activity guidelines—for people with and without diabetes—revolve around moderate to vigorous aerobic exercise and resistance training, what about doing other intensities of exercise? I often advocate alternating hard and easy training days, along with varying the pace of training even within a single exercise session, for best results, but fitness gains can also vary in both directions when you change up the intensity of activities. But do alternate or low-intensity ones count for cross-training, or are they not intense enough?

Whether or not an activity should count may depend on your goals. If your primary objective is to get more fit, doing anything that is moderate or higher in intensity is likely better for raising your aerobic or muscular fitness—although how well you respond depends in large part on your initial level of fitness (i.e., the lower it is, the more you gain from doing any activity at any intensity). Also keep in mind that training gains are activity-specific, meaning that you may be in great shape for walking or running and no shape at all for swimming or rowing. If your goal is more health-related, such as managing blood glucose or health issues, many lower-intensity or alternate activities may be even more appropriate to do than more intense ones.

Let’s take a closer look at some of these other activities. In this category, I would include a lot of less traditional ones, such as stretching, yoga, tai chi, qigong, and even table tennis.

• Stretching and flexibility exercise:

Everyone loses flexibility with aging, but having diabetes can speed up those losses. Any exercise done to prevent or reverse this trend will help you in countless ways. Simply stretching your calves appears to be helpful in many ways (2). Years ago, we studied the impact of doing stretching with resistance training in adults with type 2 diabetes and found that it can increase the range of motion around a variety of joints (3). A more recent study looked at how calf-stretching may help prevent and treat diabetes-related foot ulcers (4), and who would not want to prevent those if they can? I personally have found that stretching my feet (the plantar fascia in particular) and ankles has really increased my flexibility when trying to touch my toes. Stretching all of your major muscles group is recommended at least 2 to 3 days per week.

• Yoga:

Yoga has been frequently studied, but only recently have the studies on populations with diabetes had a high enough quality to be definitive. The findings are that yoga helps people with diabetes—when it comes to overall blood glucose levels (5) and fasting glucose and body mass index (6), even when compared to other higher-intensity exercise. It can even improve quality of life in this population (7) -and lower oxidative stress (8), which is associated with many diabetes-related health complications. So feel free to yoga away!

• Tai chi or qigong:

The potential benefits of tai chi, a low-intensity activity that involves strength and stretching moves and only low-intensity aerobic training, are vast and include potential improvements in fasting blood glucose, certain blood lipid levels, and BMI (9). In fact, tai chi may be more effective than aerobic training for certain metabolic measures, such as A1C and HDL-cholesterol. In some instances, qigong may be even better than tai chi, but it differs by outcomes (10); however, many health improvements have been noted with this family of activities (11), including better cognition and balance (12). It may just be time to take up one of these activities in your spare time for added health benefits.

• Table tennis:

Not many studies on this sport/activity have been done in people with diabetes, but we did one a while ago. In that one small study, playing table tennis for 30 minutes (against a ball robot) was as beneficial as walking after dinner when it came to measures like heart rate variability and mood, but self-paced walking (on a treadmill) had a slight edge when it came to lowering the spike in blood glucose after eating (13). As table tennis is a popular activity and competitive sport in many countries around the world, its potential health impacts should not be ignored. It may be time to dust off that table in your garage and grab a paddle after all.

Overall, doing a variety of physical activities in a given week is optimal—both for physical (joint/muscle/fitness level) and emotional health. So, try a new activity at any intensity level today, especially one that you find enjoyable.

References:

1.   Bales J, Bales K. Training on a knife’s edge: how to balance triathlon training to prevent overuse injuries. Sports Med Arthrosc Rev. 2012;20(4):214-6.

2.   Medeiros DM, Martini TF. Chronic effect of different types of stretching on ankle dorsiflexion range of motion: Systematic review and meta-analysis. Foot. 2018;34:28-35.

3.   Herriott MT, Colberg SR, Parson HK, Nunnold T, Vinik AI. Effects of 8 weeks of flexibility and resistance training in older adults with type 2 diabetes. Diab Care. 2004;27(12):2988-9.

4.   Maeshige N, Uemura M, Hirasawa Y, Yoshikawa Y, Moriguchi M, Kawabe N, et al. Immediate Effects of Weight-Bearing Calf Stretching on Ankle Dorsiflexion Range of Motion and Plantar Pressure During Gait in Patients with Diabetes Mellitus. Int J Low Extrem Wounds. 2021:15347346211031318.

5.   Gupta U, Gupta Y, Jose D, Mani K, Jyotsna VP, Sharma G, et al. Effectiveness of Yoga-based Exercise Program Compared to Usual Care, in Improving HbA1c in Individuals with Type 2 Diabetes: A Randomized Control Trial. Int J Yoga. 2020;13(3):233-8.

6.   Jayawardena R, Ranasinghe P, Chathuranga T, Atapattu PM, Misra A. The benefits of yoga practice compared to physical exercise in the management of type 2 Diabetes Mellitus: A systematic review and meta-analysis. Diab Metab Syndr. 2018;12(5):795-805.

7.   Cui J, Yan JH, Yan LM, Pan L, Le JJ, Guo YZ. Effects of yoga in adults with type 2 diabetes mellitus: A meta-analysis. J Diabetes Investig. 2017;8(2):201-9.

8.   Venugopal V, Geethanjali S, Poonguzhali S, Padmavathi R, Mahadevan S, Silambanan S, et al. Effect of Yoga on oxidative stress in type 2 diabetes mellitus: a systematic review and meta-analysis.  Curr Diabetes Rev. 2021 Apr 4. doi: 10.2174/1573399817666210405104335.

9.   Guo S, Xu Y, Qin J, Chen Y, You Y, Tao J, et al. Effect of tai chi on glycaemic control, lipid metabolism and body composition in adults with type 2 diabetes: A meta-analysis and systematic review. J Rehabil Med. 2021;53(3):jrm00165.

10. Li X, Si H, Chen Y, Li S, Yin N, Wang Z. Effects of fitness qigong and tai chi on middle-aged and elderly patients with type 2 diabetes mellitus. PLoS One. 2020;15(12):e0243989.

11. Zhang YP, Hu RX, Han M, Lai BY, Liang SB, Chen BJ, et al. Evidence Base of Clinical Studies on Qi Gong: A Bibliometric Analysis. Complement Ther Med. 2020;50:102392.

12. Cai H, Li G, Jiang S, Yin H, Liu P, Chen L. Effect of Low-Intensity, Kinect™-Based Kaimai-Style Qigong Exercise in Older Adults With Type 2 Diabetes. J Gerontol Nurs. 2019;45(2):42-52.

13. Colberg SR, Grieco CR, Somma CT. Exercise effects on postprandial glycemia, mood, and sympathovagal balance in type 2 diabetes. J Am Med Dir Assoc. 2014;15(4):261-6.

Here We Go Again: The Low-Carb vs. High-Carb and Training Debate

Who knew I’d be talking about carbohydrate intake and being active for the third time this year, but here we go again! A lot of confusion still exists related to the practice known as “carb loading” as well.  Do you need to do it? Should you? How do you know?

This controversy keeps coming up because of all the low-carb diet followers out there, especially many people with diabetes. At the American Diabetes Association Scientific Sessions this year (held virtually in June 2021), the MOST popular session of the entire conference was the one I set up to debate low-carb and high-carb eating and athletics (discussed in Diabetes In Control in July) with a virtual meeting record of 3,300 views!

As I commented recently, this debate is still ongoing in active individuals without diabetes. However, some facts are irrefutable, and these can impact the decisions that you make about your dietary plan with diabetes:

• During harder exercise, your active muscles rely almost exclusively on carbohydrate as a fuel. Carbs are converted into energy (ATP) more quickly and with less oxygen required than fat. Carbs acts like high-octane gas while other types give you less energy for the same amount of fuel (and supply it more slowly). You must use carbs to do hard exercise.
• Your body can adapt to a lower carb intake and increase fat use during exercise, at least to a limited extent (see comment above). However, adapting takes weeks and your performance can be negatively impacted if you go low-carb without time to fully adapt.
• While you are in the process of adapting, your training may suffer and you may feel bad during workouts. This may be why many athletes adopt a strategy of periodically doing endurance training with less carb intake but take in unrestricted carbs when competing (i.e., train low-carb and compete high-carb). Following this strategy may help you adapt faster compared to having a low- or a high-carb intake all the time (1).
• Even if you do adapt to lower carbs during training, your body will not necessarily use fewer carbs when active. It may just shift downward the intensity at which you cross over from less carb to more fat use (2). This shift towards greater fat use occurs naturally whenever your muscles start to run out of stored glycogen; the rate of glycogen use appears largely unchanged by low-carb training, however.
• No matter how you eat and train, for intense events sprinting and power lifting, a chronic low-carb intake may be detrimental to your performance if your muscle glycogen stores are low. On the other hand, for endurance activities, you can usually at least maintain how well you perform after adapting to low-carb eating, but chances are your performance may not be better (see first comment above).

When it comes down to it, instead of carb loading, simply varying your carb intake may be as beneficial to performance. For instance, you may want to endurance train with a lower carb intake to increase your ability to oxidize fat, but take in more carbs leading up to any events and during events to maximize your storage. People with diabetes just have to make sure that they are keeping their blood glucose levels in check during any high-carb intake.

If attempting to carb load for even a day (which is usually long enough if you rest or taper) and you take insulin, cover the carbs with enough rapid-acting insulin to keep your blood glucose as near normal as possible to maximize muscle glycogen storage. (Glucose cannot get into muscles cells during rest without insulin.) Most people take in plenty of carbs if they are eating enough overall and even as low as 40 percent of calories from carbs. Effective carb loading does not require you to eat a pasta dinner or massive amounts of starchy foods.

If you take any carbs in during exercise, which most people do during longer events and training even without diabetes, you’ll need very little insulin coverage (if any). If you limit your carb intake afterward, though, you may increase your chances of getting a nighttime low blood glucose, particularly if you use insulin (3). If you do not use insulin, you are unlikely to need any extra carbs during most shorter activities, regardless of how easy or hard you work out. Supplemental carbs are mainly for longer events (90 minutes plus) and for insulin users.

That said, anyone on a low-carb diet may benefit from supplementing with carbs as needed during endurance activities or training (1). Aim for a maximum of 75 grams per hour during prolonged or multi-day activities. During intermittent sports like hockey or soccer, 30 to 60 grams of carbs per hour may prevent fatigue or lows near the end of a game. Keep monitoring your blood glucose, though, as going too high or low can have negative effects on performance.

Primary reference: Colberg SR, Nutrition and exercise performance in adults with type 1 diabetes. Canadian Journal of Diabetes, 44(8):750-758, 2020 (https://doi.org/10.1016/j.jcjd.2020.05.014)

References:

1..  Impey SG, Hearris MA, Hammond KM, Bartlett JD, Louis J, Close GL, et al. Fuel for the Work Required: A Theoretical Framework for Carbohydrate Periodization and the Glycogen Threshold Hypothesis. Sports Medicine. 2018;48(5):1031-48. doi: 10.1007/s40279-018-0867-7. PubMed PMID: 29453741.

2.   Chang CK, Borer K, Lin PJ. Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance? J Hum Kinet. 2017;56:81-92.(doi):10.1515/hukin-2017-0025.

3.   Scott SN, Anderson L, Morton JP, Wagenmakers AJM, Riddell MC. Carbohydrate Restriction in Type 1 Diabetes: A Realistic Therapy for Improved Glycaemic Control and Athletic Performance? Nutrients. 2019;11(5):1022. doi: 10.3390/nu11051022. PubMed PMID: 31067747.

Can Diabetes Affect Your Ability to Exercise in Hot Weather?

By Sheri Colberg, PhD

The arrival of summer brings to mind visions of people having fun in the sun and recreating on the beach, but hotter weather also creates greater risks related to dehydration and heat stress for people who are physically active outdoors. Aging by itself negatively affects the body’s ability to dissipate heat in both dry and humid environments (1), but having diabetes further increases the risk of developing heat stress during outdoor activities, especially when it’s hot and/or humid (2). Whole-body heat loss may be impaired due to abnormal skin circulation and decreased sweating (3), both of which can lead to increases in body temperature and heart rate.

People with type 1 diabetes (4) and type 2 diabetes (5) may have impaired regulation of body heat. In particular, athletes with type 1 diabetes may sweat less, especially when they are working out at more intense levels (4), and many adults with type 2 diabetes have a reduced ability to be active in the heat. The good news, though, is that these individuals with diabetes can still acclimate to doing aerobic or resistance training in hotter environments.

What do people need to do to acclimate? Adequate hydration is key to maintaining blood volume and blood flow, both of which affect body cooling during physical activities. Overheating in any environment occurs more easily when dehydrated (6). Dehydration leading to less sweating is more likely when glucose levels are elevated and can lead to chronic hyperglycemia (5). So, everyone needs to closely monitor and manage blood glucose during training or competition in the heat to avoid making any existing impairments in the ability to cool the body worse.

Plain water is usually effective for hydrating during activities lasting an hour or less. During longer workouts or events, water can also suffice for hydration, but sports drinks or other fluids may provide extra carbohydrate to keep blood glucose from dropping too much. In general, consuming about 1 liter of fluid per hour during activities in the heat is recommended (7)—but don’t take in too much or water intoxication can result. Hydrate after activities to restore fluids and electrolytes lost through sweat and breathing (8) and manage blood glucose.

Do the following to minimize the risk of exercise-related heat stress:

• Avoid exercising during the hottest times of the day; choose morning or evening times
• Stay out of direct sunlight during exercise whenever possible
• Wear loose-fitting, light-colored exercise clothing
• Take in extra fluid and electrolytes (e.g., salt) every day while acclimating
• Don’t wait until you’re thirsty to drink fluids, and avoid alcohol since it’s dehydrating
• Give yourself a couple of weeks to fully acclimatize to exercising in the heat
• Try to stay cool until you start exercising, or exercise indoors
• During hot-weather exercise, watch for signs and symptoms of heat-related illness
• If unfit or new to exercise, be extra cautious when working out in the heat

References:

1. Notley SR, Poirier MP, Hardcastle SG, et al. Aging Impairs Whole-Body Heat Loss in Women under Both Dry and Humid Heat Stress. Med Sci Sports Exerc. 2017;49(11):2324-32.
2. Poirier MP, Notley SR, Boulay P, et al. Type 2 diabetes does not exacerbate body heat storage in older adults during brief, extreme passive heat exposure. Temperature. 2020;7(3):263-9.
3. Notley SR, Poirier MP, Sigal RJ, et al. Exercise Heat Stress in Patients with and without Type 2 Diabetes. JAMA. 2019;322(14):1409-11.
4. Carter MR, McGinn R, Barrera-Ramirez J, et al. Impairments in local heat loss in type 1 diabetes during exercise in the heat. Med Sci Sports Exerc. 2014;46(12):2224-33.
5. Kenny GP, Stapleton JM, Yardley JE, et al. Older adults with type 2 diabetes store more heat during exercise. Med Sci Sports Exerc. 2013;45(10):1906-14.
6. Colberg SR. Nutrition and Exercise Performance in Adults with Type 1 Diabetes. Can J Diabetes. 2020;44(8):750-8.
7. Yardley JE, Colberg SR. Update on Management of Type 1 Diabetes and Type 2 Diabetes in Athletes. Curr Sports Med Rep. 2017;16(1):38-44.
8. Evans GH, James LJ, Shirreffs SM, Maughan RJ. Optimizing the restoration and maintenance of fluid balance after exercise-induced dehydration. J Appl Physiol. 2017;122(4):945-51.

Key Exercises and Training for Aging Successfully and Living Your Best Life

As the years have rolled by, nothing has become more clear to me with each passing day than the fact that aging successfully requires a lot of work. When it comes to our bodies, nothing rings truer than “If you don’t use it, you lose it.” This is particularly true when it comes to preventing declines arising from disuse, but also when trying to slow down the normal impacts of aging.

The function of our bodily systems peaks at around age 25 and declines over time. As a result, your maximal aerobic capacity decreases over time, even with constant training, reflective of declines in maximal heart rate. What’s more, your balance ability gets worse (particularly after age 40), bones get thinner, muscles atrophy, reflexes get slower, and recovery from workouts takes longer. Aging is not for sissies (but it beats the alternative)!

The good news is that is it possible to at least slow how rapidly most of these systems decline by changing how you live your life. By including regular physical training, better nutrition, adequate sleep, and stress management, you can delay or prevent a lot of normal aging and reverse decrements caused by inactivity, neglect, disuse, and abuse of our bodies. (The only one we really can’t slow or reverse is our neurological decline.)

It starts to seem like preventing additional declines from inactivity or inadequate training gets to be a full-time job as you get older, and you have to keep adding in additional exercises, stretches, and activities. A fitness instructor recently confirmed that it’s a bit like playing whack-a-mole: fix one weak area or physical problem and another one pops up. Welcome to aging!

So what can you do to live your best life, physically and mentally? I would suggest adding at least these (and many other) critical exercises to your weekly routine:

Cardiorespiratory fitness: Cardio workouts with faster training intervals

In addition to doing regular cardio activities like walking, cycling, and swimming, add in some faster intervals into any workout, such as walking faster for 10 to 60 seconds at a time during your normal walk or doing a hill profile on a cardio training machine. Doing so will increase your fitness more and improve insulin sensitivity for longer. It’s also fine to do high-intensity interval training (HIIT) at least once a week, but start out slowly and progress slowly to prevent injuries and demotivation. Not all your workouts should be equally intense, and varying your aerobic activities also lowers the risk of getting injured.

Muscular strength and endurance: Resistance training exercises

It is easy to work on your muscle strength and muscle endurance by doing a series of resistance exercises targeting your major muscle groups (in the upper body, lower body, and core areas). Pick at least 8 to 10 exercises that cover all these areas and do them at least two to three days per week. It’s fine to use your own body weight, household items (like full water bottles), hand weights, or resistance bands as resistance—you don’t have to have access to a gym or leave home. Adding in these exercises to your weekly routine is critical to aging well and being able to live independently throughout your entire lifespan.

Balance ability: Standing on one leg at a time (and other balance exercises)

This simple exercise involves standing on one leg for a minute, switching to the other leg, and repeating. Have something you can grab onto nearby, such as the back of a chair. You can hold on with both hands, one hand, one finger, or nothing as you get better at balancing. To challenge yourself, move your free leg in different directions (e.g., out front, to the side, behind you) while standing on the other one, or practice standing on uneven surfaces, such as a cushion. If your balance ability is really getting to be an issue, include other balance training activities each week as well.

Joint mobility and cartilage health: Stretches for all your joints

Do a series of flexibility exercises that stretch your joints in all their normal directions to maintain and increase their range of motion. With aging, we are all losing flexibility and diabetes can accelerate this loss when extra glucose sticks to joint surfaces (cartilage) over time and makes them more brittle. Try to stretch at least two to three days per week. The older you get, the longer you should hold each stretch (up to a minute on each one), and you may need to add in specialized stretches (such as for your calves or hips) to really work tighter joints to enhance your mobility and balance ability.

Bone strength: Weight-bearing activities and/or resistance training exercises

Your bones stay stronger when you put normal stress on them regularly, such as carrying your own body weight around when walking or jogging or doing resistance exercises with your upper body or carrying grocery bags. If you stay sedentary, your bones will lose minerals faster and get thinned out more quickly, and non-weight-bearing activities like swimming and cycling just don’t have the ability to build bone as much as weight-bearing ones. Try to adequately stress your bones to stimulate the bone mineral density to stay higher—at least two to three days per week.

Basic mobility and self-care: Wall sits and/or sit-to-stand exercise

Until you start to get older, you seldom think about how difficult it can be to get up out of a chair or off the sofa. Many older people get heavier and weaker and start to have trouble doing these basic maneuvers, which are critical to living well independently. To improve your ability, practice doing wall sits, which involves sitting against a wall with your hips and knees at 90 degree angles and your feet straight below your knees for as long as you can. This exercise will also help prevent knee pain and problems. Alternatively, you can do sit-to-stand exercises where you sit on the edge of an armless chair and practice getting up without using your arms. (This is also often called the “getting up from the toilet” exercise.)

Sexual enjoyment (and incontinence): Kegel exercises

Also known as pelvic floor muscle training, Kegel exercises can help with stress incontinence (i.e., urinating a little when sneezing or laughing) and normal incontinence (both urinary or fecal), and they may enhance your sexual pleasure to boot. The easiest way to identify the pelvic floor muscles is to stop your urine flow while urinating or tighten the muscles that keep you from passing gas. To do Kegels, imagine you are sitting on a marble and pretend you’re lifting it up by tightening your pelvic muscles and holding them contracted for as long as you can; do this a few times in a row. When your muscles get stronger, you can do these exercises while sitting, standing, or walking. Both men and women can and should do Kegel exercises regularly.

Is Weight Loss or Physical Activity More Important for Preventing Type 2 Diabetes?

Ever since the U.S. Diabetes Prevention Program (DPP) multicenter trial was completed nearly two decades ago (1), we have known that it is possible to prevent, or at least delay, prediabetes (an insulin resistant state) from progressing into full-blown type 2 diabetes. Why? Diabetes risk was reduced by 58% in the “intensive lifestyle” (ILS) participant group and by 31% in the metformin (an oral glucose-lowering medication) participants compared to no intervention (“placebo” group). For participants who were 60 years or older, lifestyle changes worked much better to prevent diabetes than taking metformin (1,2).

As an exercise physiologist, what I have always disagreed with about the DPP trial is its greater emphasis on weight loss than on physical activity. Admittedly, ILS consisted of a goal of losing 7 percent of body weight (only 14 pounds if you weight 200) by following a low-calorie, low-fat, high fiber diet and doing at least 150 minutes per week of a moderate physical activity (like brisk walking). In a follow-up report (2), for every kilogram (2.2 pounds) of weight loss, type 2 diabetes risk was reduced by 16%.

However, in the DPP, both a lower percent of calories from fat and increased physical activity predicted weight loss. Typically, it is easier for people to lose some weight than to keep it off afterwards, and that study reported that increased physical activity was critical to maintaining a lower weight. Even among the 495 participants who failed to meet the weight loss goal of 7% loss the first year, those who exercised regularly still had a 44% lower diabetes incidence (without weight loss!), and only the regular exercisers kept the weight off (2). In my mind, that means that physical activity is likely more important.

For the 10-year DPP Outcomes Study (DPPOS) and the 15-year follow-up, all original DPP participants were offered intensive lifestyle management training (3,4). During the first 7 years, diabetes incidence rates decreased by 42% in those who had not been doing ILS or taking metformin previously (DPP placebo group) and by 25% in the DPP metformin participants (who had the option to keep taking metformin); by way of comparison, those in ILS during the DPP increased diabetes rates by 31% during follow-up (5). That seems like a horrible outcome for the DPP ILS participants who only had to keep up their lifestyle changes.

On further analysis, no combination of changes in weight, physical activity, diet, smoking, and antidepressant or statin use explained the DPPOS lower rates of diabetes progression in placebo and metformin groups, but…weight gain was associated with higher rates in the ILS group. That also seems like a bad outcome. Did these participants stop exercising or become less active during the follow-up study? Statistically speaking, physical activity was not a factor that accounted for their increased diabetes rates, but in practical terms, even small changes in activity can make a big difference in blood glucose and body weight management. It’s also important to note that the ILS group still had the overall lowest rates of diabetes incidence at the 15-year mark, even though they rose closer to the other groups (4).

Although the DPP established combined lifestyle improvements (diet, activity, and weight loss) as the best way to prevent type 2 diabetes, a more recent study attempted to determine how much exercise alone contributes, along with the optimal intensity of exercise since most DPP participants did brisk walking (6). Three study groups did varying amounts and intensities of exercise while the fourth followed diet and exercise strategies like the DPP to lose 7% of body weight. Interestingly, a higher amount of moderate-intensity exercise by itself (the equivalent of walking about 13.8 miles weekly) was very effective at improving how well people responded to consuming a large amount of glucose (via an oral glucose tolerance test) despite a relatively modest 2-kilogram (4.4-pound) loss of body fat, which suggests that a higher amount of moderate-intensity walking may work as well as combined approaches for preventing the progression to type 2 diabetes. It should be noted, however, that only the diet and exercise group experienced a decrease in fasting blood glucose levels in that study (6).

So, does physical activity matter? I still maintain that it is as important as—if not more important than—losing weight when it comes to preventing diabetes and managing insulin resistance (even if you have type 1 diabetes), especially since most people have trouble keeping the weight off and only regular physical activity is guaranteed to help you do that. Importantly, the latest follow-up study coming from the DPP just confirmed that I (and others) were right all along (7). In that study, cumulative diabetes incidence remained lower in the lifestyle compared with the placebo and metformin randomized groups and this difference could not be explained by changes in body weight. Examining the self-reported physical activity overall revealed that physical activity was inversely related to diabetes, meaning that the more active people were over time, the less likely they were to develop it, regardless of their body weight. Eureka!

Losing the right type of weight matters as well (that is, mostly fat and not much muscle), so if you are dieting, make sure you include regular activity (particularly resistance exercise) to retain more of your insulin-sensitive muscle mass (8).

References:

1. Knowler WC, Barrett-Connor E, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393-403.
2. Hamman RF, Wing RR, et al. Effect of weight loss with lifestyle intervention on risk of diabetes. Diabetes Care. 2006;29(9):2102-7.
3. Diabetes Prevention Program Research Group, Knowler WC, et al. 10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. Lancet. 2009;374(9702):1677-86.
4. Diabetes Prevention Program Research Group. Long-term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15-year follow-up: the Diabetes Prevention Program Outcomes Study. Lancet Diabetes Endocrinol. 2015;3(11):866-75.
5. Diabetes Prevention Program (DPP) Research Group, Hamman RF, et al. Factors affecting the decline in incidence of diabetes in the Diabetes Prevention Program Outcomes Study (DPPOS). Diabetes. 2015;64(3):989-98.
6. Slentz CA, Bateman LA, et al. Effects of exercise training alone vs a combined exercise and nutritional lifestyle intervention on glucose homeostasis in prediabetic individuals: a randomised controlled trial. Diabetologia. 2016;59(10):2088-98.
7. Kriska AM, Rockette-Wagner B, Edelstein SL, et al. The Impact of Physical Activity on the Prevention of Type 2 Diabetes: Evidence and Lessons Learned From the Diabetes Prevention Program, a Long-Standing Clinical Trial Incorporating Subjective and Objective Activity Measures. Diabetes Care. 2021;44(1):43-49.
8. Colleluori G, Aguirre L, et al. Aerobic plus resistance exercise in obese older adults improves muscle protein synthesis and preserves myocellular quality despite weight loss. Cell Metab. 2019;30(2):261-273.e6.

Exercising in a Pandemic: 10 Easy Exercises to Build a Strong Core Without Leaving the House

Just in time for the novel coronavirus (COVID-19) social distancing and closures of gyms and fitness centers in many areas, here’s a revisit of many important core exercises you can do at home to keep yourself strong and healthy. Download the free illustrated PDF (Chapter 21) for illustrations. You can also find a variety of other at-home exercises on Diabetes Motion Academy Resources for free download.

Many people are stuck at home for one reason or another think they can’t work on staying fit, but the truth is that you can get a stronger core and stay fitter without leaving home. You’d be amazed at how easy it is to get your fit on.

Remember: Your body core — the muscles around your trunk and pelvis — is particularly important to keep strong so that you can go about your normal daily activities and prevent falls and injuries, particularly as you age. Having a strong body core makes you better able to handle your daily life, even if that’s just doing grocery shopping or playing a round of golf.

Core exercises are an important part of a well-rounded fitness program, and they’re easy to do at home on your own. To get started on your body core workout, you don’t need to purchase anything. (Some of the advanced variations do call for equipment like a gym ball or dumbbells.)

Tip: Include all 10 of these easy core exercises in your workouts, doing at least one set of 15 repetitions of each one to start (where appropriate). Work up to doing two to three sets of each per workout, or even more repetitions if you can. For best results, do these exercises at least two or three nonconsecutive days per week; muscles need a day or two off to fully recover and get stronger. Just don’t do them right before you do another physical activity (because a fatigued core increases your risk of injury).

#1: Abdominal Squeezes

This exercise (Figure 21-1) is great for working your abdominals and getting your body core as strong as possible. If you’re female and have had gone through a pregnancy at some point, getting these muscles in shape doing these squeezes is a must.

1. Put one of your hands against your upper stomach and the other facing the other direction below your belly button.
2. Inhale to expand your stomach.
3. Exhale and try to pull your abdominal muscles halfway toward your spine.

This is your starting position.

4. Contract your abdominal muscles more deeply in toward your spine while counting to two.
5. Return to the starting position from Step 3 for another count of two.

Work up to doing 100 repetitions per workout session.

#2: Planks or Modified Planks

Nobody likes doing planks, but they get the job done when it comes to boosting the strength of your core. Both planks and modified planks (Figure 21-2) work multiple areas, including your abdominals, lower back, and shoulders.

1. Start on the floor on your stomach and bend your elbows 90 degrees, resting your weight on your forearms.
2. Place your elbows directly beneath your shoulders and form a straight line from your head to your feet.
3. Hold this position as long as you can.

Repeat this exercise as many times as possible during each workout.

#3: Side Planks

A modification of regular planks, this side plank exercise (Figure 21-3) works some of the same and some slightly different muscles that include your abdominals, oblique abdominal muscles, sides of hips, gluteals, and shoulders. Try doing some of both types for the best results.

1. Start out on the floor on your side with your feet together and one forearm directly below your shoulder.
2. Contract your core muscles and raise your hips until your body is in a straight line from head to feet.
3. Hold this position without letting your hips drop for as long as you can.
4. Repeat Steps 1 through 3 on the other side.

Switch back and forth between sides as many times as you can.

Tip: Try these plank variations to mix things up a bit:

* Raised side plank: Lifting both your top arm and your leg upward brings other muscles into play and makes your core work harder to maintain balance, but don’t let your hips sag.

* Gym ball side plank: Resting your supporting arm on a gym ball, use your core muscles to control the wobble to further strengthen your side muscles.

* Side plank with lateral raise: While holding the side plank position, slowly raise and lower a light dumbbell or other weight with your top arm to improve your coordination and strength.

* Side plank pulse: From the side plank position, add a vertical hip drive by lowering your hips until they’re just off the floor and then driving them up as far as you can with each repetition of this move.

#4: Bridging

If you work on your abdominal strength, you also need to build the strength in your lower back to keep things balanced. Bridging (Figure 21-4) is a good exercise to do that as it works your buttocks (including gluteals), low back, and hip extensors. Remember to breathe in and out throughout this exercise.

1. Slowly raise your buttocks from the floor, keeping your stomach tight.
2. Gently lower your back to the ground.
3. Repeat Steps 1 and 2.

Tip: Try the bridging with straight leg raise variation: With your legs bent, lift your buttocks up off the floor. Slowly extend your left knee, keeping your stomach tight. Repeat with the other leg. Do as many repetitions as possible.

#5: Pelvic Tilt

An easy exercise to do, the pelvic tilt (Figure 21-5) works your lower back and
lower part of your abdominals.

1. Lie on your back on the floor with your knees bent and feet flat on the floor.
2. Place your hands either by your sides or supporting your head.
3. Tighten your bottom, forcing your lower back flat against the floor, and then relax.
4. Repeat Steps 2 and 3 as many times as you can.

#6: Superhero Pose

Whether you want to leap a tall building with a single bound or not, try doing this superhero pose exercise (Figure 21-6) to get a stronger core. It works many areas, including your lower back, upper back, back of shoulders, and gluteals.

1. Lie on your stomach with your arms straight over your head.
2. Rest your chin on the floor between your arms.
3. Keeping your arms and legs straight, simultaneously lift your feet and your hands as high off the floor as you can.

Aim for at least three inches.

4. Hold that position (sort of a superhero flying position) for 10 seconds if possible, and then relax your arms and legs back onto the floor.

Tip: If this exercise is too difficult, try lifting just your legs or arms off the floor separately — or even just one limb at a time.

#7: Knee Push-Ups

Push-ups are hard to do if you haven’t built up the strength in your shoulders yet, so this knee version (Figure (21-7) is an easier way to start for most people. This exercise works your chest, front of shoulders, and back of upper arms.

1. Get on your hands and knees on the floor or a mat.
2. Place your hands shoulder-width apart on the floor.
3. Tighten your abdominal muscles to straighten your lower back and lower yourself down toward the floor as far as you can without touching.
4. Push yourself back up until your arms are extended, but don’t lock your elbows.

Tip: If knee push-ups are too hard for you, try doing wall push-ups to start instead. Stand facing a wall at an arm’s length and place your palms against it at shoulder height and with your feet about a foot apart. Do your push-ups off the wall.

#8: Suitcase Lift

This exercise (Figure 21-8) is the proper way to lift items from the floor. Before you begin, place dumbbells or household items slightly forward and between your feet on the floor. You work the same muscles used in doing squats (lower back and lower body) with this activity.

1. Stand in an upright position with your back and arms straight, with your hands in front of your abdomen.
2. Bending only your knees, reach down to pick up the dumbbells.
3. Grab the dumbbells or items in both hands and then push up with your legs and stand upright, keeping your back straight.

#9: Squats with Knee Squeezes

These squats (Figure 21-9) are not your normal squats. They’re more like a combination of squatting and wall sitting with a twist. You work the front and back of thighs, inner thighs (adductors), hip flexors and extensors all with this one exercise.

1. Stand with your back against the wall, with your feet aligned with your knees and straight out in front of you.
2. Place a ball or pillow between your knees and hold it there with your legs.
3. Inhale to expand your stomach and then exhale and contract your abdominal muscles.
4. Bend your knees and lower yourself into a squat.

Warning: To avoid injuring your knees, don’t bend them more than 90 degrees.

5. Squeeze the ball with your thighs, drawing your stomach muscles more deeply toward your spine.
6. Do as many squeezes as you can up to 20 and then return to the starting position.

#10: Lunges

Lunges (Figure 21-10) are a common activity to work on the front and back of thighs, hip flexors and extensors, abdominals, and lower back all with one exercise. Do them with proper form to avoid aggravating your knees, though.

1. Keep your upper body straight, with your shoulders back and relaxed and chin up.
2. Pick a point to stare at in front of you so you don’t keep looking down, and engage your core.
3. Step forward with one leg, lowering your hips until both knees are bent at about a 90-degree angle.

Make sure your front knee is directly above your ankle, not pushed out too far, and don’t let your back knee touch the floor.

4. Focus on keeping your weight on your heels as you push back up to the starting position.

Tip: To prevent injuries, if you feel any pain in your knees or hips when you do a lunge, do the following instead:

• Take smaller steps out with your front leg.
• Slowly increase your lunge distance as your pain gets better.
• Try doing a reverse lunge (stepping backward rather than forward) to help reduce knee strain.

                                                                                                                                               

Excerpted from Colberg, Sheri R., Chapter 21, “Ten Easy Exercises to Build a Strong Core Without Leaving the House” in Diabetes & Keeping Fit for Dummies. Wiley, 2018.

Debunking Some Physical Activity and Training Myths

Photo by The Lazy Artist Gallery on Pexels.com

By Sheri Colberg, PhD

How often have you heard that things about physical activity and exercise training that you thought sounded correct, but found out later they were totally wrong? If you hang out at a gym or even talk with training coaches, you’ll hear about everything, including contradictory statements about how to be active the right way.

Should you work out in a “fat burning” range? Is weight training going to make you bulk up? Will your muscles turn to fat if you stop working out? Do you need to eat a lot more protein to get bigger muscles? Confused? Here is the truth about some of the more common myths you’ll hear about being active.

Myth: Exercising regularly makes you more tired.

Although you may feel somewhat tired during a workout, when you’re done you usually feel more invigorated after you recover, not less. Doing any regular physical activity is guaranteed to raise your overall energy levels and may you better able to handle everything you have to undertake. If you’re having trouble concentrating at work or getting too stressed, it helps to take a short walk or do any type of physical activity to clear your mind, bump up your energy levels, and decrease your mental stress. Doing regular physical activity also helps you sleep better at night, leaving you more refreshed and energetic during the day.

Myth: If you want to lose fat, you have to work out at a “fat burning” range.

Exactly what is “fat-burning” range you see on a lot of aerobic exercise machines? You have to understand what fuels your body uses during rest and exercise. Typically, during rest 60% of your energy needs are supplied by fat (stored or eaten), with the other 40% coming from carbohydrates. As soon as you start to do any type of physical activity, though, carbs go up to a much higher percentage of your total energy supply. In fact, when you’re doing just moderate aerobic exercise like brisk walking, you’ll use very little fat, so you’re burning mostly carbs even when you’re in a so-called “fat-burning” range. During more vigorous exercise, your body can’t use fat effectively, so almost all energy is supplied by carbs when you’re working out hard. You do use slightly more fat at a lower intensity, but most of its use is during your recovery from exercise, so just try to expend as many calories during exercise as possible without worrying about what types of fuels are supplying them.

Myth: When you don’t use your muscles, they turn into fat.

Have you ever found yourself looking at someone who used to be more fit and thinking that his or her muscles had really turned into flab? While there is no discounting how it looks, it is physically impossible for inactive muscles to turn into fat. What is really happening is this: when you work your muscles out regularly, they can increase in size or simply look more toned; if you stop using them, the muscle fibers will atrophy and disappear—similar to what happens with aging if you don’t fight against it. Then, as your muscle mass becomes less, your caloric needs decrease, and if you don’t start eating less, you’ll gain weight—as fat that then can be stored under your skin (among other places). The reverse is true as well. If you drop body fat, your muscles will look more defined simply because there is less fat in your skin covering them. The bottom line is that it is never good to lose muscle mass, but if you don’t gain fat weight at the same time you lose some muscle, you’ll look thinner, but not like fat replaced your muscles.

Myth: Weight training will bulk you up.

This myth probably arose because you can look bigger as your muscles are stimulated to expand out with heavy weight training. Women are especially worried about bulking up and getting bigger arms or legs. Remember how losing muscle can make you look thinner if you’re not gaining fat at the same time? Well, the same applies here, only in reverse. If you’re losing fat all over (including from under your skin) while you’re gaining muscle mass, you’ll stay about the same size. If you gain muscle without losing fat, you may look slightly bigger, or simply more toned. Either way, most people don’t gain enough muscle from weight training to ever look bulked up. More likely, you’ll just look more toned. When you first start exercising, your weight may go up slightly or just not come down as much as you think it should, simply because as you gain muscle while losing fat, the heavier of the two (muscle) will keep your scale weight higher. Focus less on your scale weight and more on your measurements and how well your clothes fit.

Myth: No pain, no gain.

If you’ve ever hung around a gym, you’re sure to have come across this myth. The “pain” part of exercise results from the build-up of acids in active muscles (like lactic acid), and acids drop the pH of your muscles and sensitize pain receptors. Usually, it’s just a sign that you’re working hard or that your muscle is fatiguing. However, you can certainly have gains in your strength and endurance without pushing yourself to the point of having a lot of pain in the process. The more fit you become, the more easily your body can clear out those excess acids produced by physical activity. Too much pain can also signal that you’re likely to get injured.

Myth: Lifting weights slowly builds larger muscles.

Remember how we just debunked the “no pain, no gain” myth? If you try lifting weights more slowly, you’ll certainly feel the pain, but it absolutely doesn’t mean that your muscle or strength gains will be more. On the contrary, lifting weights slowly when you could lift them faster will build more muscular endurance, while lifting the heaviest weight as quickly as possible will recruit extra muscle fibers and cause you to build bigger muscles. So, the rule of thumb should be that if you are lifting a weight slowly, but could lift it faster, you either need to move it faster or try a heavier weight for optimal results.

Myth: Working on your abdominal muscles will give you a flat belly.

You’ve probably always heard that if you want to get rid of that stomach flab that you have to do a lot of abdominal work, but don’t be fooled into believing that. As much as we’d all like to pick and choose where we lose our fat, it is not possible to spot reduce, and doing hundreds of crunches will not make you lose stomach fat any faster than you lose it from the rest of your body. If you want a flat belly, you can certainly work on toning up your abdominal region, but focus more on simply burning off excess calories. Doing harder workouts will also build more muscle, and having more muscle increases your daily caloric needs. One side benefit of including abdominal exercises, though, is that having toned abs makes it easier for you to pull in your stomach in case anyone is looking at it, even if you can’t spot reduce there.

Myth: The more exercise you do, the better off you’ll be.

There is a limited benefit to anything and that includes exercise that is excessive. When you do more than 60 to 90 minutes of aerobic exercise daily, you’re much more likely to develop overuse injuries—such as stress fractures, tendinitis, bursitis, and other joint issues. You don’t want to get injured because then you’ll have trouble working out. You are better off doing slightly more intense exercise for less long, which you can do with any type of interval training (including some of the latest crazes like HIT and CrossFit). You can push yourself a bit harder from time to time during a workout, or do the whole thing at a higher intensity if you can, while cutting back on the duration—and you will gain the same benefits, or even more, from your workout. Most of us don’t have time to work out all day anyway, so it’s good to know that we really don’t need to.

Myth: If you want to gain muscle mass, eat more protein.

Ah, yes, the protein myth. It is true that you have to eat some protein to gain protein (muscles are made of amino acids, the building blocks of protein). And, yes, physically active people do need more protein than sedentary ones, but not that much more. In fact, no training athlete needs more than 1.6 to 1.7 grams of protein per kilogram of body weight (~0.75 grams per pound), or just twice that of a sedentary person. Does that mean you need to take protein supplements or up the protein in your diet? Not usually. Most Americans already eat well over 15% of their calories as protein: about 75 grams of daily protein in a 2,000 calorie diet (or 112 grams per 3,000 calories), more than enough to cover protein needs. Taking in some protein (especially whey) with carbs right after hard workouts may be beneficial, but make sure your protein is coming from good sources without a lot of extra saturated or trans fats. Instead of spending money on supplements, try eating more egg whites or drinking chocolate milk post-exercise.

Myth: If you’re not sweating, you’re not working hard enough.

Everyone equates sweating with working hard, but that simply isn’t always the case. People vary in their sweating rates. Being physically trained improves your ability to sweat more and to start sweating sooner, but men always tend to sweat more than women. Sweating is related to not only exercise intensity, but also to the environment. If it’s hot and humid, you’re going to sweat more, even if you’re not working hard. You will also sweat less if you’re dehydrated or lose too much fluid while you’re working out as your body has mechanisms to limit fluid losses to keep enough in your blood. So, sweating is often not reflective of your effort level.

Aiming for an Ideal Exercise Blood Glucose

There is no official ideal blood glucose range to start with and maintain during physical activity, but we do know that being too low negatively impacts performance, as does being too high. As for what blood glucose target or range most athletes aim for, it depends on a number of factors, including the type, intensity, and duration of their activity. A consensus statement about exercise and type 1 diabetes published in The Lancet in 2017 suggested that a reasonable target for most people doing aerobic exercise lasting up to an hour is 126 to 180 mg/dL (7.0 to 10.0 mmol/L), only aiming higher for added protection against lows in some situations (1).

For anaerobic (power) exercise or high-intensity interval training session, you may want to start with your glucose lower—around 90 to 126 mg/dL (5.0 to 7.0 mmol/L) simply because the intensity of the activity may cause your blood glucose to stay more stable, fall less than during aerobic workouts, or possibly even rise slightly (1).

An ideal or optimal blood glucose target during most physical activities may be in the range of 108 to 144 mg/dL (6.0 to 8.0 mmol/L).

Most of the athletes surveyed for The Athlete’s Guide to Diabetes (2019) said the range of 80 to 180 mg/dL (4.5 to 10.0 mmol/L) was their stated target during exercise. Only a few of them aim for lower or higher than that range, although most admittedly have a narrower target.

Canadian Scott L. from British Columbia agrees with recommended ranges for performance reasons, saying, “My aim is to be 6.0 to 8.0 mmol/L [108 to 144 mg/dL]. I feel the strongest at 6.0 mmol/L [108 mg/dL], but it gives me less opportunity to catch lows. Above 10.0 mmol/L [180 mg/dL], I start to feel a little sluggish—and above 15.0 mmol/L [270 mg/dL] very sluggish!”

But the blood glucose target depends on the activity and other factors. Just to give you a few examples, Chris C., a resident of New Jersey, tries to keep her blood glucose as close to 100 mg/dL (5.6 mmol/L) as she can, saying, “With high-intensity interval training my glucose will jump here and there throughout the workout with the intensity of the exercises. As soon as I am done, though, my glucose usually starts to drop.”

New York resident Riva G. uses a similar range of 80 to 150 mg/dL (4.5 to 8.3 mmol/L) for all her activities, but she likes to start on the higher end for walking. Jason O. of Ireland also varies his target based on his activity: 126 to 180 mg/dL (7.0 to 10.0 mmol/L) for cycling, just to make sure he has some leeway if he needs to make a big effort, and a tighter range of 90 to 144 mg/dL (5.0 to 8.0 mmol/L) for walking. For surfing, he aims for 5.5 to 9.0 mmol/L (100 to 162 mg/dL) in the water but uses a different target range of 4.5 to 7.5 mmol/L (80 to 135 mg/dL) for all other sports. Likewise, Ginger V. from Vermont sets the lower end of her range at 80 mg/dL (4.5 mmol/L) for all her activities, but she varies the higher end depending on whether she is doing fasted (120 mg/dL [6.7 mmol/L]) or nonfasted (150 mg/dL [8.3 mmol/L]) exercise.

The key is to find out what works best for you and maintain your blood glucose in that range during activities. Keep in mind that your glucose target may vary with the type of activity you do (mode, intensity, duration, etc.), exercise timing, insulin (or other medication) regimen, recent or concurrent food intake, environmental conditions, and multiple other factors. It’s not usually a one-size-fits-all solution.

References:

1. Excerpted from Colberg, SR, Chapter 5, “Using Technology and Monitoring to Enhance Performance,” in The Athlete’s Guide to Diabetes: Expert Advice for 165 Sports and Activities. Champaign, IL: Human Kinetics, 2019.

Updated Federal Physical Activity Guidelines: Do They Apply to People with Diabetes?

In mid-November 2018, the U.S. Department of Health and Human Services finally released new physical activity guidelines (as a 2^nd edition) to update their previous set from a decade before (1,2). Various activity guidelines for adults with diabetes have been updated several times in the interim, including a 2010 position statement on exercising with type 2 diabetes (3) published jointly by the American College of Sports Medicine and the American Diabetes Association; a 2016 ADA position statement on exercise and physical activity for all types of diabetes (4); and a consensus statement on being active with type 1 diabetes published in The Lancet in 2017 (5).

In those three sets of recommendations specific to diabetes, it was clear that everyone with diabetes can benefit from being more regularly active. Adults with diabetes should undertake a variety of activities, including aerobic, resistance, flexibility, and balance training (the last one particularly for adults over 40 or anyone with neuropathy), as well as stay more active on a daily basis just doing lifestyle activities or sitting less for better blood glucose management and weight control. The activity recommendations for adults and youth with diabetes have essentially been the same for everyone else of a similar age without diabetes.

So, what do the new federal guidelines add to the mix, if anything? Based on a review of the current research, the biggest change from the previous set of guidelines is likely that you don’t need to be active for a minimum of 10 minutes at a time for it to be beneficial to fitness and well-being. Given that many studies in the past decade have shown that breaking up sedentary behavior with short (3-minute) breaks can alter metabolism for the better, these recommendations are not surprising. They also recommend that people should sit less overall, again not a shocking guideline at this point. Studies done with people with diabetes have reached the same conclusions, so these updates certainly apply to everyone.

Another change in the federal guidelines applies to the weekend warriors: they now state that adults can derive similar health benefits if they perform all their weekly recommended physical activity in a single day or two rather than over the course of multiple days. However, whether this guideline applies as directly to people with diabetes is questionable. Past guidelines (3,4,5) have recommended that adults with diabetes not go more than two days without doing some physical activity, and many have recommended doing daily or near daily exercise for better blood glucose management. Given that the enhancing effects of your last bout of physical activity on insulin sensitivity may only last 2 to 72 hours, it seems unlikely that people with diabetes will gain all the same benefits by being a weekend warrior only—at least not when it comes to blood glucose management through reduced insulin resistance. For now, the recommendations for people with diabetes to do some type of exercise at least every other day will likely remain in place for that reason.

Finally, the new guidelines expanded out recommendations for all adults to get 150 minutes of moderate aerobic activity or 75 minutes of intense activity (or a combination thereof) each week to include up to double that amount—300 minutes moderate or 150 minutes intense aerobic training—and beyond for additional benefits. As if the bar weren’t set high enough already, you now have to find even more time to be active to gain optimal health benefits. While we already knew this was true, apparently the federal government also now recognizes how important it is for all of us to be the anti-couch potato and get as much as activity as possible to optimize our collective health! Luckily, the guidelines for doing resistance training at least two days a week are still unchanged, although we all know that doing three nonconsecutive resistance workouts a week is a preferable goal to maximize muscle gains and prevent losses of muscle (where we store carbohydrates) from aging and disuse.

In summary, these new federal physical activity guidelines really did not change what we should be doing already: getting at least 75 to 150 minutes of aerobic exercise weekly depending on its intensity (but closer to double that amount for optimal health), doing resistance training at least twice a week (but preferably three), stretching regularly, working on our balance ability if we’re older, moving more, sitting less, getting up more often, and taking the stairs instead of the elevator. So, go get active!

References:

1. Physical Activity Guidelines for Americans, 2nd Edition, 2018. Accessed at https://health.gov/paguidelines/second-edition/.
2. Executive Summary: Physical Activity Guidelines for Americans, 2^nd Edition, 2018. Accessed at https://health.gov/paguidelines/second-edition/pdf/PAG_ExecutiveSummary.pdf.
3. Colberg SR, Sigal RJ, Fernhall B, Regensteiner JG, Blissmer B, Rubin RR, Chasan-Taber L, Albright AL, and Braun B. Exercise and type 2 diabetes: The American College of Sports Medicine and the American Diabetes Association: Joint position statement. Diabetes Care, 33(12): e147–e167, 2010.
4. Colberg SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, Dempsey PC, Horton ES, Castorino K, and Tate DF. Physical activity/exercise and diabetes: A position statement of the American Diabetes Association. Diabetes Care, 39(11); 2065–2079, 2016.
5. Riddell MC, Gallen IW, Smart CE, Taplin CE, Adolfsson P, Lumb AN, Kowalski A, Rabasa-Lhoret R, McCrimmon RJ, Hume C, Annan F, Fournier PA, Graham C, Bode B, Galassetti P, Jones TW, Millán IS, Heise T, Peters AL, Petz A, and Laffel LM. Exercise management in type 1 diabetes: a consensus statement. Lancet Diabetes Endocrinology, 5:377–390, 2017.