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The best way to deal with problems associated with diabetes and exercise
begins with understanding of what goes on in the metabolic system of
normal people and what the differences are for diabetics. Only with
such understanding can you make intelligent choices about
pharmacological tactics. Relying on rules of thumb can cause more
problems it solves because of the wide variability of individual
responses and the wide variety of diseases that fall under the rubric
of diabetes. Not to mention, I have seen postings where the rules of
thumb were clearly misunderstood. |
| The new study, published in the journal Psychosomatic Medicine, showed that
the benefits of exercise persisted even longer. After six months, eight per
cent of those in the exercise group saw their depression return, compared
with 38 per cent who only took the drug. |
| When a normal person starts to exercise, the insulin output of his
pancreas goes down. At first blush, this seems backward since the
muscles are working hard and therefore require more glucose to be
transported from the blood into the cells. There are two reasons more
glucose can be transported with less available insulin. The first is
that during exercise insulin becomes much more efficient. The mechanism
of this effect is not fully understood, but it helps overcomes the
reduction in circulating insulin. |
| Exercise also produces effects at longer time scales. Sometime after
exercise, there is often a take up of blood glucose by the muscles to
replenish depleted stores. This most often occurs an hour or two after
exercise, but has been reported in the range of 1/2 hour to 48 hours.
Again, as is the case during exercise, artificially high insulin levels
will lead to hypoglycemia. The last rule of thumb is to watch for
hypoglycemia after exercise. |
| So much for too much insulin. What happens when the circulating insulin
level is too low? When levels are so low that even the increase in
insulin efficiency doesnt overcome the defect, glucose isnt
transported into the cells. Worse, since insulin levels are low the
liver continues to pump glucose into the blood. The result is bg levels
rise with exercise. The muscles get stressed due to lack of fuel and
the metabolism of fats kicks in, ketones start being produced and the
danger of ketosis or ketoacidosis looms. This is the basis for another
rule of thumb which is often misunderstood. The rule is usually stated
dont exercise when your bg is above 240 mg/dl (13.3 mmol/l) and
ketones are present in the urine. This makes sense because those are
signs that you have inadequate insulin supplies -- thats how many of
us got diagnosed. Exercise in those circumstances will make things
worse, not better. On the other hand, if you are 300 mg/dl (16.7
mmol/l) because you just drank a large regula. |
