The word is out! For people with diabetes, physical activity is a must or as we say in our program, “It’s non-negotiable.” Whether one chooses to increase daily steps in a walking program, bicycling, water aerobics or dancing the benefits are inevitable. Blood glucose, blood pressure, cholesterol are all better controlled and of course weight loss in the form of fat loss occurs. Let us not forget, however the importance of weight/resistance training and its role in achieving improved physical activity.
Most people gain about ten pounds every ten years after the age of 40, but they also lose five pounds of lean muscle. That equates to an actual weight gain of 15 pounds! An appropriate meal plan developed by a registered dietitian can help get rid of the fat, but it will do very little to revive lost muscle. In order to stay strong and maintain lean muscle mass weight training is imperative, especially as one gets older. Also, as one increases strength, less time is spent in wheelchairs and individuals are less dependent on others to do things for them.
Increased muscle mass developed through weight training aids in the management of diabetes. Muscle is a major clearance site for circulating blood glucose. In type 2 diabetes, the body loses sensitivity to the blood glucose regulating hormone insulin. Blood glucoses build up within in the blood and as a result the stage is set for the development of complications. As lean body mass (e.g. muscle) increases, greater amounts of blood glucose are cleared from the blood. The greater the muscle mass the more calories burned at rest, equating to greater amounts of weight loss. It is important to note that the abdominal fat mass lost during weight training is the key behind the improvements in insulin sensitivity.
Researchers have investigated this relationship between weight training and diabetes. In one particular study published in Diabetes Care, researchers gathered 36 subjects between the ages of 60-80 and assigned them to one of two exercise groups: high intensity weight training and moderate weight loss; or moderate weight loss plus a control program, for six months. Subjects in the control group did stretching exercises instead of lifting weights.
The goal of the high-intensity lifting program was to train with weights that were about 80% of the maximum poundage a subject could lift for one repetition. The weight lifting participants did nine different exercises three times a week that worked muscles in their legs, arms and abdomen.
A test of long term blood glucose control showed significant improvements in the weight lifting group after three months of exercise, and improved further by six months. Subjects in both groups lost weight and fat, but the weight lifters showed gains in lean body mass while those who didn’t lift weights showed muscle mass losses.
Researchers concluded that by encouraging high-intensity weight lifting for people with diabetes, complications could be reduced in the long term. A similar study also published in Diabetes Care involving people with type 2 diabetes and high intensity weight training showed an A1c reduction from 8.7% to 7.6%. In addition, 72% of subjects assigned to the weight training protocol had a reduction in the dose of prescribed diabetes medications, all this after only 16 weeks!
For those in the non-weight training group, no change in A1c result occurred and a 42% increase in prescribed diabetes medication was noted. If, as a healthcare professional, you are concerned regarding the amount of weight lifted in the studies discussed, keep in mind that several studies have shown that weight training with as little as a pound and a half can boost strength and endurance, especially in the elderly adult.
Before any person with diabetes begins an exercise program it is extremely important that they have a medical exam. This should include an exercise test with EKG monitoring, especially if they have cardiovascular disease, are over the age of 35, have high blood pressure, elevated cholesterol, and smoke or have a family history of heart disease. Individuals with proliferative retinopathy should avoid weight lifting and should be encouraged to perform low impact, stressing cardiovascular conditioning (e.g. swimming/water aerobics, walking, stationary cycling).
Any person who is interested in beginning a resistive training program should be supervised by a certified exercise professional. It is important that the following components be included during the weight training instructional session:
- Determine what the person wants to achieve with the strengthening program
- Individuals who are interested in basic fitness can select exercises that use each other major muscle groups of the body (shoulders, back, chest, abdomen, and legs).
- Advise patients to exercise in a specific order to use the larger muscle groups first and then move to the smaller muscle groups.
- By working the larger muscle groups and then proceeding to the smaller groups, the demanding exercises are performed early in the workout while the energy supply is the greatest and the individual has a larger source of energy.
- For individuals with diabetes and no known cardiac disease, it is important to find out what physical characteristics are necessary to attain their goal before determining the appropriate resistance.
- The resistance used is determined through the individual’s repetition maximum (RM), which is defined as the amount of weight that allows for successful completion of a specified number of repetitions (no more, no less).
- For both muscular strength and endurance, 8 to 12 repetitions would be the most appropriate range.
- When working with persons with cardiac disease, particular attention must be focused on blood pressure and heart rate response. It is important to start with a lighter load and perform exercises that utilize a smaller amount of muscle mass, which in turn will decrease the myocardial oxygen demand on the heart.
- Performing 1 to 2 sets of each exercise has been proven to be beneficial to increase general muscle strength and endurance.
- Instruct the patient with low fitness level or little training experience to complete just 1 set of each exercise for the first 4 to 6 weeks. Once they are comfortable with the exercise and have demonstrated good technique, the number of sets can be increased.
- Rest for an adequate amount of time between sets to allow for successful completion of the next set.
- Before starting the weight lifting session, the individual should be taught proper weight lifting technique:
- Keep the body properly aligned
- Breathe properly, exhaling during the actual lift and inhaling while lowering the weight back down to the apparatus.
- Controlling the lifting movement.
- Obtain adequate range of motion
- Adjust the equipment to fit the body frame.
Patients do not have to rely on resistance equipment. They can exercise the same joints using inner tubes and elastic bands, cuff and hand weights, free weights dumbbells and wall pulleys. Individual contractions should not be held for more than 5 to 6 seconds to avoid large increases in cardiac afterloading.
How much aerobic and resistance training is enough? The Centers for Disease Control and Prevention as well as the American College of Sports Medicine recommend that adults engage in at least 30 minutes of moderate-intensity aerobic activity (walking, bicycling, water aerobics, dancing) on at least 3 nonconsecutive days up to 5 times per week (more will only improve health); scheduled every other day. For resistance training, even less frequent activity can significantly benefit your health. Amazingly, back strength begins to increase with only 75 to 90 seconds of training a week. However, for general strength and endurance gains it is recommended that at least 2 days at 15-20 minutes per session be performed.
Kristina Sandstedt, MS, CDE, CPT, ACSM ES received her Master of Science degree from the University of Montana- Missoula. She is a Certified Diabetes Educator, Certified Insulin Pump Trainer and Certified as a Clinical Exercise Specialist through the American College of Sports Medicine. She is the Diabetes Program Coordinator for Boone Hospital’s Diabetes Self-Management Center in Columbia, MO.
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Dunstan, D. Zimmet, P., et al. International Diabetes Institute in Victoria, Australia.
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