each time you lowerit, shoot for 20seconds of exercise untUyou can't goanymore.
Nearly fromthe beginning you're wipedout, yetyoukeep doing it at lower and lower resistance.
This is a realworkout.
Your goal wiU be to get your heart rate up to (but not above) the training level recommended by your physician.
If you can't reach the recommended rate when you can barely notice the resistance of your machine,increase your speeduntil you get to your pulse target.Try to maintain this rate for up to 5 minutes.
A major goal of cardiovascular exercise is to enhance your heart rate recovery time, i.e., to shorten it. (Cardiologists now beUeve that the faster your heart rate slows from your target to near resting rate, the better your cardiacfitness.) Aminimal test of recovery would be to slow your heart rate by 42 beats per minute from your maximum within 2 minutes of slowing your feet until you are barely walking or pedaling.
Todo this you sprint at top speed for 2-5 minutes and then drop to a veryslowspeedfor 3-5 minutes,and then sprint again,over and over.
When you think you've had enough,lowerthe resistance to zero but keep your legs moving veryslowly until your pulsehas returned to a value about 30 percent above your starting point.
This slow exercise pumps blood back to your heart from your legs, thereby greatly re ducing the hazard of a postworkoutheart attack.
I recommend that rather than timing your workout, you look at the calorie counter on the machine, if it has one, and decide on a particu lar number of calories that you want to shoot for.
Calories are a mea sure of work done and therefore a reasonable gauge of your workout.
Minutes or even mUes don't take effort into account.
I aim for about 200 calories.
When it getsup to that range,I caU it quits.
But the point of this kind of exercise isn't weightloss, so don't start looking at the calorie counter thinking that if you burn 200 more caloriesyou'U lose another pound , exercise just doesn't work that way.
IncidentaUy, I have a retired patient who actuaUy has the time and the stamina to continue intermittent sprinting for an hour.
AN IMPORTANT CAUTION
If you're doing cardiovascular exercise of this type,you haveto be very careful,especiaUy if you're a long-term diabetic, or a recent-onset dia betic over the ageof forty,or havea famUy history of coronary disease.
Using Exercise to Enhance Insulin Sensitivity 233
One rule isthatyouneverfinish acardiovascular workout and stop cold.
I had an overweight nondiabetic cousin who started jogging when he was about fifty years old.
He was in his second month of exercising, not doing anything more than jogging with friends.
One day, after they stopped jogging, he dropped dead of a heart attack.
He and his jogging buddies were in the habit of stopping cold after their run to chat.
Stopping cold is an extremely bad idea , if people are going to drop dead of heart attacks from running orbiking, it's mostoften im mediately after the exercise thatthis happens.
Why?
WhUe you're exercising, your heart isbeating veryrapidly because it and your legs require a lot of blood.
By pumping your legs up and down, you're pumping blood from your legs back to your heart.
The muscles thatare demanding alot of blood are both in yourlegs andin your heart, but theblood's getting pumped back to your heart byrun ning.
If you stop cold, your muscles are stiU going to demand alot of blood , they've been depleted of oxygen and glucose , and gravity isgoing to help them get theblood.
The problem is, they're no longer pumping theblood back to theheart.
Suddenly your heart isdeprived and, if your coronary arteries are narrowed by atherosclerosis, you're set up for a heart attack.
Whether you're on a treadmiU, bike, or stair climber, cut the resis tance setting to zero and proceed at averyslow pace after yourwork out until your heart rate slowly comes down to no higher than about 30 percent above your initial starting rate.
If your resting pulse is 78, you don't want to stop your biking, walking, or step cUmbing untU your heart rate is 101 or below.
PROGRESSIVE EXERCISE
As your strength and endurance increase for any exercise, it wiU be comeprogressively easier to perform.
If it becomes too easy, youwon't get any stronger.
The key to getting progressively more strength and endurance is to make the exercise progressively more difficult.
This canbe done for almostanyactivity.
If you are Ufting weights, for example, every few weeks (or months) you can add a very smaU weight (say a separate 2^-pound plate) to the weight stack for anyexercise.
When doing a cardiovascular exer cise, you might try to increase your maximum heart rate by, say, 2 beats per minute every 2 months, byincreasing your resistance setting
234 Treatment
or your speed.
A swimmer can assign a fixed time period,say30 min utes, for doing laps.
The goal would be to graduaUy increase the num ber of laps.
Thus, aftera month you might increase your speed to get 15V2 lapsinstead of 15lapsin 30 minutes, and so on.
Of course,a wa terproof wristwatch would be helpful.
Even walking can evolveinto both an endurance and a bodybuUd ing activity.
AU you need is awristwatch, a few Ughtweight dumbbeUs, and a pedometer.
The pedometer is a small gadget from a sporting goods store that you cUp onto your belt.
It measures distance by counting your steps.
Suppose you wish to set aside 30minutes per ses sion for walking.You begin by walking at a leisurely pace for 15 min utes and then returning at the same pace.
Record your distance from the pedometer.Thereafter, try to walkat least that distance in the same time period.
After ten sessions, you might try to increase distance by 5 percent over the same time.
If you increase distance by this amount every ten sessions, you'U eventuaUy find yourself running.
You can then graduaUy increase your running speedin the same fashion.
Supposeyour doctor hastold you not to run because of a bad knee or fragUe retinal blood vessels.
Limit your speed to a fast walk, but start swinging your arms a Uttle bit.
Over time, try swinging them higher and higher.
When you think they are going so high that you look siUy, start with the dumbbeUs.
You might begin with a pair of 1-pound dumbbeUs and short swings of the arms.Wear gloves if the dumbbeUs feel cold.Again,graduaUy increase the distance you swing.
When you eventuaUy feel you look siUy, try 2-pound dumbbeUs.
After a yearor two, you may be goingat a very fast walk, swinging 5-pound (or even heavier) dumbbeUs.
Imagine what your physique wiU look like then.
You'U also probably feel younger and healthier.
The exercises I've mentioned above are by no means the only ones.
There are countless different ways you can exercise , voUeybaU, snowboarding, surf-kayaking, cross-country skiing, you name it.
The most important considerations are keeping within the restrictions your physician might place on your activity, and discovering what you like to do best , and sticking with it.
After that, aU you have to do is monitor and correct your blood sugars, record the exercise on your Glucograf form, and keep exercising in a progressive fashion.
The payoff, longer life,lowerstress, weight loss if you're overweight, and better overaU health , is usuaUy worth the time and effort.
15 Oral InsuHn*Sensitizing Agents, Insulin~Mimetic Agents, and Other Options
I f dietandexercise are not adequate to bring your bloodsugars un der control, the next level of treatment to consider is oral blood sugar-lowering medication, commonly known as oral hypo glycemicagents (OHAs).
There are three categories of OHAs, those that increase sensitivity to insulin, those whose action resembles that of insuUn, and those that provoke your pancreas to produce more insulin.
The first group is known as insulin sensitizers (or ISAs, for insulin-sensitizing agents); the second are the insulin mimetics (or IMAs, for insulin-mimetic agents), which act like insulin but do not buUd fat.
FinaUy, there are the original OHAs, like sulfonylureas.
I only recommend the insuUn sensitizers and insulin mimetics, for reasons that wiU become plain in shortorder. (Some drug companies have combined pancreas-provoking OHAs with insulin sensitizers, a move I strongly chaUenge.
TeU yourdoctor you do not want any prod uct containing an agent that works by causing the pancreas to make more insulin.This includes the old sulfonylureas and the new,simUar drugs caUed megUtmides and phenylalanine derivatives/) For people who stUl have sufficient insuUn-producing capacity, in sulin sensitizers alone may provide the extra help they need to reach their blood sugar target.
Some insulin-resistant individuals who pro-
In addition to causing beta cell burnout,sulfonylureas also impair circulation in the heart and elsewhere by closing ATP-sensitive potassium channels that re laxbloodvessels. Theyhave beenshown to increase aU causes of mortaUty, in cluding deaths from heart diseaseand cancer.
236 Treatment
duce Uttle or no insuUn on their own may find a combination of in sulin sensitizersand insulin mimetics usefulin reducing their doses of injected insulin.
There are three ISAs currently on the market, and at this writing I prescribeaU three of them , metformin (Glucophage), rosigUtazone (Avandia), and piogUtazone (Actos).
RosigUtazone and piogUtazone have simUar effects upon blood sugar,so it servesno purpose for one individual to use both.
A note: Sincebrand names vary from country to country, I wiU use only the generic names in my discussion of drugs in this chapter.
In my experience, however, not all genericmetformins match the effec tiveness ofGlucophage.
Some of the OHAs on the market are not insulin-sensitizing or -mimetic.
Instead, they provokethe pancreasto produce more insulin.
For several reasons, this is considerably less desirable than taking a medication that sensitizes you to insulin.First,the pancreas-provoking OHAscan causedangerously lowblood sugar levels (hypoglycemia) if used improperly or if meals are skipped or delayed.
Furthermore, forcing an already overworked pancreas to produce yet more insulin can lead to the burnout of remaining beta ceUs.
These products also facUitate beta ceU destruction by increasing levelsof a toxic substance caUed amyloid.FinaUy, it has been repeatedly shown in experiments , and I have seen it in my own patients , that controlling diabetes through blood sugar normaUzation can help restore weakened or damaged beta ceUs.
It makes absolutely no sense to prescribe or rec ommend agents that wiU cause them renewed damage.
In a nutsheU, pancreas-provoking drugs are counterproductive and no longer have any placein the sensible treatment of diabetes.
As it's far more productive to talk about good medicine, I wiU leave pancreas-provoking OHAsin the past, where even the newer ones be long, and from here on out discussonly insuUn sensitizersand insulin mimetics.
Then, at the end of the chapter, I wiU look at possible new treatment options for three specialcircumstances.
INSULIN-SENSITIZING AGENTS
The great advantage of insulin sensitizers is that they help to reduce blood sugar by making the body's tissues more sensitive to insulin,
OralInsulin-SensitizingAgents, Insulin-Mimetic Agents, and OtherOptions 237