11) EXERCISE AND TYPE 2 DIABETES
a) Introduction
Exercise is somewhat unique among all the various treatments for type 2 diabetes. Every single other treatment has "experts" who loudly opinion that the treatment doesn't work: weight loss doesn't work, diet control doesn't work, don't control carbohydrate intake, go ahead and eat refined carbohydrates, go ahead and eat feedlot saturated fats, don't take medications, etc. But on exercise the evidence is just too overwhelming. The more exercise anyone with type 2 diabetes does the better the disease will be controlled and the slower it will progress. And no "expert" is contradicting that.
There is absolutely no question that exercise of any type benefits a person with type 2 diabetes. Independent of weight loss, exercise increases insulin sensitivity, raises beneficial HDL cholesterol levels, and lowers triglycerides. And exercise is essential to maintain weight loss. One study has shown that less than 40% of individuals with diabetes exercise on a regular basis. This survey had 22,000 individuals and 75% of these individuals had been told to exercise by their physicians. What is really discouraging is that the worse the diabetic condition, the less likely the individual was to exercise. In other words, the individuals who absolutely must exercise are not exercising. And we won't pull any punches, this is a matter of personal responsibility, not a matter of genetics or hormones. Type 2 diabetes causes depression and depression can cause a person to put off an exercise program. But even a little bit of will power can punch through this. And even those with sizable disabilities can find suitable exercises.
If the diabetes is not well controlled and blood sugar readings are consistently above 170 mg/dl, then caution needs to be advised in an exercise program. Exercise activates two organs in the body: it activates the pancreas to produce more insulin and the liver to produce more blood sugar. If the pancreas cannot produce more insulin, then the blood sugar put out by the liver can increase blood sugars to dangerous levels. The diabetes needs to be brought under better control with insulin injections prior to starting an exercise program.
The type of exercise recommended is dependent on the type of damage to be controlled, whether or not it is concerned with the small blood vessels in the body serving such organs as the kidneys, eyes, brain and nerves ("microvascular") or with the large blood vessels serving the legs, the heart, and the lungs (macrovascular" or "heart disease"). The higher priority for anyone with diabetes is to control "heart" disease, so lengthy "aerobic" exercise at least three times a week is recommended as the first level of exercise for a person with diabetes. "Aerobic" exercise is walking, running, etc. for a minimum of 150 minutes per week and a minimum of 30 minutes per session (50 minutes is much better). But it is also desirable to control small blood vessel disease which leads to kidney problem, nerve damage and blindness. Small blood vessel damage is benefited by just about any sort of exercise of any intensity at frequent intervals. The important point for microvascular damage is that the exercise should be frequent, with some exercise every 16 hours or less.
From a small blood vessel viewpoint it is important for a person with diabetes to exercise more frequently than a "normal" individual because the blood sugar (glucose) reducing effects of exercise typically last only 10 to 16 hours (some research indicates that resistance exercise with weights and resistance based gym equipment can extend the blood sugar reducing effect up to 30 hours). So the ideal is exercise to some extent each morning and each evening. Three times a week is fine for the "normal" individual; it doesn't cut it for the person with diabetes. It is important for a person with diabetes to get some exercise every day. So at least get out and walk every day. Any exercise is good for small blood vessel disease, even going up and down the stairs or walking around a mall. Studies have shown that exercise not only improves the outlook for those with type 2 diabetes, exercise also improves brain function considerably and significantly reduces the depression that often accompanies "getting older".
At the other end of the spectrum, large blood vessel disease has different exercise requirements. Beneficial effects on large blood vessel disease changes (heart disease, PAD, strokes, etc. the big killers of diabetes) require high intensity exercises for at least half an hour (preferably one hour) at least three times a week. But then there is the matter of patient compliance, some people just won't do high intensity exercise. If that is the case, frequent low intensity exercise is decidedly better than no exercise at all.
Most people with type 2 diabetes also have at least some degree of heart problems, so any exercise program has to be a gradual increase in intensity over a year or more. It is also vital that the individual slowly warm up with gradually increasing exercise and then gradually and slowly cool down with the exercise tapering off. Specifically the legs need to stay in motion for at least 10 minutes after a vigorous workout. The legs have a series of one way valves in their blood vessels which enable the legs to basically function as a "helper heart" and keep the blood circulating and the muscles fed with oxygen. If an individual suddenly stops vigorous exercise, the heart has to suddenly "go it alone" and a heart attack is a common result.
Any vigorous exercise must be done more that two times per week; "weekend warriors" have a huge risk of heart attack and stroke. If an individual has type 2 diabetes and the choice is between vigorously exercising once a week and no exercise, no exercise is better! It is always best to check with your doctor prior to beginning any exercise program, especially if you have known heart problems. Most doctors will do some sort of heart health workup prior to allowing their diabetic patients to begin an exercise program. Also be aware that doctors are inbetween a rock and a hard spot when it comes to vigorous exercise. In our lawsuit happy culture if a doctor prescribes vigorous exercise they risk a lawsuit since vigorous exercise will slightly increase the possibility of a heart attack during exercise, especially if the vigorous exercise is not gradually built up over at least several months. But without the vigorous exercise a patient is much more likely to die in his sleep of a heart attack. And most heart attacks occur when the individual has not vigorously exercised. i.e. "in their sleep". But the doctor won't be sued if the patient dies in their sleep. If an individual is happy with 5% to 15% improvements in the outlook for type 2 diabetes and its accompanying heart disease, light to moderate exercise might do it. But if one wants a 50% to 80% improvements in outlook for both diseases, vigorous exercise is required. All the research supports this.
Of course "vigorous" is relative. The increase in heartbeat required to define "vigorous" is dependent on age and is called the "target heart rate". It typically will be modified by a percentage which is indicative of your heart health. Typically someone with type 2 diabetes will start out with a target of 70% of their "maximum target" heart rate, which is 220 minus their age. So if a type 2 diabetic is 60 years old their initial target is 70% of 160 or 112 beats per minute. If they are 80 years old this initial target becomes only 98 beats per minute. This heart rate can be calculated by counting the pulses in the wrist, it can be read off a monitor around the arm or chest, or it can be read off an exercise machine. After a year or more of vigorous exercise someone with type 2 diabetes might be approved by their doctors to go for as high as 90% of their maximum. The approved rate will rarely go above 90%.
Current Chapter: 11) EXERCISE
a) Introduction
b) Exercise and low Blood Sugar
c) Exercise and Weight Lose
d) Aerobic Exercise and Heart Disease
e) Exercise and Peripheral Arterial Disease
f) Proper Resistance Training
g) Exercise Myths
h) Exercise, Stress and Diabetes
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