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Anne Peters, MD, is director of the clinical diabetes programs at the University of Southern California (USC). Her latest book, “Conquering Diabetes” (Hudson Street Press, April 2005), has been hailed as one of the most “real” and readable diabetes guidebooks to date.
Diabetes Health recently had the opportunity to talk with Dr. Peters about her work with Olympic swimmer Gary Hall, Jr., and the delicate balance between blood glucose levels and sports.
Gary Hall, Jr., writes in his “Olympic Diaries” that he thought his swimming career was over until he spent an afternoon driving around Santa Monica, California, with you. What did you tell him?
Finding a doctor is like finding a friend. This relationship worked because we believed in each other. That day I just chatted with him, thinking, Could we form a partnership? Is he really willing to work with me?
In general, I’d say the doctor has to be willing to work with the individual patient’s own learning style. My thoughts were, Here’s this Olympic athlete who has already trained and competed. What do I know about his body? And about his sport? I’m the one who has a lot of learning to do.
What are some of the most notable situations or challenges you’ve faced in advising diabetes patients about exercise? Did you and Gary Hall or other top athletes learn by trial and error?
I’ve helped treat patients in professional waterskiing, golfers (long drivers), scuba divers, lots of swimmers, runners (sprinters, marathon runners, long-distance runners, hurdlers), cyclists, triathletes—almost every type of sport. What’s clear is that you have to be prepared. Patterns are only good for looking backward. They don’t tell you how you’ll respond at any given point.
Response of blood glucose differs by individual and by sport. For example, Gary doesn’t just train in the pool. He does weight training and running, too, so we had to learn his response to each activity.
Less intense activities like golfing usually don’t affect people’s BGs much (depending on whether you carry your own clubs!), and there tends to be lots of snacking, which makes it hard to track BG patterns. Oddly, I’ve had lots of patients have heart attacks on golf courses, which is strange, because it’s the least strenuous activity. Maybe when high-stress people finally take a break, their hearts give out.
Swimming actually made the lancet holes in Gary’s fingers stay open, and sometimes he could just squeeze the blood out without lancing his finger again. It was weird, but it made the testing easier. We didn’t test his forearms, because you don’t get an accurate reading there if BG levels are changing, and we wanted the most accurate results. You should use forearms for testing only if your BGs are stable.
What are the top concerns for exercising with diabetes, even for those who do not wish to compete?
First of all, no “one size fits all” for exercise. You need to establish your own starting point of fitness—your own familiarity with how your body reacts to sports.
And of course, it’s “safety first,” always. The key is to have rapid-acting carbohydrates on hand at all times. I always ask, “Do you have a plan to treat lows?” Then I deal with all the intricacies of exercise. But first I need to know that they’re safe.
You’ll find that there’s always a pattern, so I tell patients to write a log: Record your insulin dose, time of workout, activity, and what happened. Then you can make a plan to treat your own pattern.
But you also need to be ready for anything. For example, Gary always goes high during competition.except the one time he went down to 30 mg/dl. You never know. That’s just diabetes!
One school of thought is that diabetics should start with very high BG levels before exercising, so they don’t “crash.” But now many experts seem to be advising against this. What’s your standpoint on “starting glucose”?
It’s difficult to just pick a number that’s supposed to be a “starting glucose” for workouts. Timing of exercise relative to meals is very important. If you’re at 120 but haven’t eaten in hours, you will likely drop fast. So you need a snack. But if you’re at 130 and just ate a few hours before, your BG level is more steady, and you’re more able to store glucose (meaning energy).
The general rule for insulin users is to cut back their dose at the last meal before exercise. For mild exercise, you cut back by 25 percent, up to about a 75 percent insulin reduction for heavy exercise. If it’s been a long time since you’ve eaten, you won’t need any insulin change, just a snack before the workout so you won’t go too low.
Is there any “best time” to exercise?
You want to exercise at a time when you have some insulin in your body (so you don’t develop acidosis*), and you also want some food in your system to avoid lows. So the best time is actually about 90 minutes after eating.
It’s really all about the balance of the “Big Three” elements: Exercise, Insulin or medications, and Carbohydrates, plus water: you need to keep hydrated.
And not all types of exercise knock your blood glucose down. An easy jog will probably lower your blood glucose, while a spinning class can make it go up. That’s because very rigorous exercise or the stress of competition can make blood glucose rise due to stress hormones.
* Acidosis is a condition characterized by excessive acid in the body fluids.
What insulin dosing changes do you recommend for a type 1 who is starting on an exercise plan? Can exercise “destabilize” his or her BG levels?
I wouldn’t say “destabilize.” That’s too sweeping and negative. But exercise does change BG levels, just like when you’re sick, and your levels change. Diabetes is always shifting.
Exercise can affect you up to 12 hours afterward; you’re more insulin-sensitive. Overnight lows can be a problem for serious athletes. I recommend reducing insulin at the next meal after exercising if lows occur. A decrease in basal insulin overnight might also be necessary. What’s important is close monitoring to get a sense of patterns. Even if you’re not an Olympic athlete, you may need less overnight insulin when you exercise regularly.
Also, remember that BG levels are just a snapshot in time. You need to gauge, Am I going up or down? This is where continuous monitoring will revolutionize diabetes care. Unfortunately, exercise disturbed the sensors in the early models—the sweat and activity made for inaccurate readings. I’m hoping the next generation of monitors will perform better.
Well, even if you exercise, you still have diabetes. But exercise, if done regularly, can keep glucose levels for type 2s in normal range. Most of my type 2 patients can walk down a high blood glucose, even if they’re in the 300s.
I tell them that they need to start off slowly. And realize that mild exercise may not change their glucose levels immediately.
There are two very important points about exercising with type 2 diabetes. First, exercise alone will not cause weight loss. You have to reduce calorie intake for weight loss to be successful. Second, irrespective of weight loss, exercise helps improve cardiovascular fitness, as in avoiding heart disease.
Can everyone with diabetes start exercising, even if they’ve never been active before?
If someone comes to me to learn about exercise, I spend the first two weeks getting to know the person and their baseline requirements. How are they with their diabetes regularly? Then we deal with exercise. No doctor can just jump right in and say, “Here’s how you need to exercise.”
Your doctor should be looking at your family history, your lipids, whether you smoke—all the risk factors. And if you have complications—an ulcer in your foot or neuropathy—then you definitely need permission from your doctor before starting to exercise.
Sometimes older patients don’t even know they have heart disease. Most people with type 2 are at incredibly high risk and don’t know their arteries are clogged. Even for older type 1s, damage to blood vessels is a very real danger.
So it’s important to have a treadmill test for heart disease. An EKG alone isn’t enough. I need to know how your heart reacts to exercise. I want to make sure your heart is OK before you exercise. If you’re over 40 and haven’t exercised in years, you definitely should have this checked! But if you’re 40 and have been exercising for years, we’re less concerned. Still, it’s better to be safe than sorry, so I’d recommend the treadmill test as a starting point.
I did study them for Gary. Most of them are just hype. Others are highly refined training supplements for building muscle and enhancing performance. It also depends on the type of muscle you want to build, although most of the studies performed detect little difference with the supplements. The other thing to watch for at an Olympic level is to avoid using anything that could be picked up on a drug test as a banned substance.
Gary actually drank Muscle Milk and ate Platinum Performance Bars, which are high in fat, protein and fiber, to keep his nutritional needs filled without raising his BG levels. They were great. When he needed to raise his blood glucose, he would drink some sugar-containing sports drink.
For more “everyday” sports, you need different kinds of fuel depending on your workouts. You want to keep a balance between your insulin levels, your ingested carbohydrate and the release of glucose into your blood stream from your glycogen stores. For three days before a competition, you want to fill your glycogen stores so that you have stored glucose to release into your bloodstream when you are exercising. Most glycogen storage happens within 90 minutes after exercise. That is why it’s important to consume carbs after exercising and give insulin to enhance glucose uptake. Also, it’s extremely important to keep well hydrated.
My belief is that good nutrition keeps all of us—athletes and weekend warriors—in better shape than taking lots of expensive supplements that have not been proven to have much benefit.
However, if you came to me on one of these supplements, and you believe in it, I’d say OK. I wouldn’t protest unless it’s hurting you in some way—damaging your liver or putting an extra strain on your kidneys. I like to have patients bring in everything they are taking so I can make sure the supplements are safe. If they are, and a person likes them, then I think it’s fine, even if they may not be truly enhancing performance.
What are some “best practices” or lessons learned from your experience with exercise and diabetes?
In terms of getting started, realize that most people eat more when they exercise. Exercise alone doesn’t cause you to lose weight. You need to reduce calories to lose weight. But it still gives you great health benefits. A fit overweight person is much better off than an unfit overweight person.
Also, most people don’t go from A to Z right away. A rational person increases gradually. For example, they have clubs to help people train for marathons, where runners gradually work up to full speed. Inherent in working out is also adjusting your food and insulin. The key is to be prepared.
I’ve found that the patients who do best are the ones who are most involved, who ask a lot of questions and experiment themselves. I just had a patient who figured out that her BG went up after exercise, but her normal “whole correction” was too much. So now she takes a half correction after exercise. She worked out her own rules! I like that.
Essentially, I really, really want people to maintain whatever they love. I don’t want to take things away. People with diabetes feel that things are being taken away from them. So if you love lawn bowling or horseback riding, I want to help you so you can continue those activities. But if you have complications like retinopathy or such, then you do need to see a specialist for recommendations on which activities are safe.
What about your own personal exercise routine? Do you take any dietary supplements?
I don’t take supplements because my body doesn’t like them. They upset my stomach. If I could, I’d like to take a multivitamin, calcium, and vitamin B—especially calcium. But I’m very sensitive to any medication. For instance, I’m the last person to take antibiotics, and I couldn’t even tolerate prenatal vitamins when I was pregnant.
I have to rely on good nutrition and exercise. I usually eat cheese sticks for breakfast, Lean Cuisine for lunch and maybe steamed vegetables, brown rice and lean meat or fish for dinner. And I often have a glass of wine. I also snack—I rarely eat too much at one sitting. By grazing on things like carrot sticks or fruit or crackers, I never get too hungry and always have just enough fuel. I also never eat after dinner. It’s lucky, I guess, that I’m not a food person. I just eat to survive.
And as I mentioned in my book, I actually hate exercise. I just do it to stay fit. Somewhere in my early 20’s I read about the health benefits of exercise, so I made it a policy.
I used to run, but I injured my back. I’m the kind of person who gets hurt easily, but I don’t let it stop me. Now I do about 40 minutes on the treadmill for an “uphill” aerobic workout, and then about 10 minutes of weights for resistance training. I do it from 10:00 to 11:00 p.m., and each night it’s psychological torture to get myself to do it. But I’m compulsive about it. I’m certainly not an athlete, but I want to stay fit, and I always feel glad that I exercised when I am done.
What would your message be to people in the diabetes community who are serious about exercise?
My top “sound bite” would be that while exercise is important for everyone, it is imperative for people with diabetes. Diabetes is not a barrier to intense exercise, as long as you have the patience to learn how to adjust your medications and food intake to achieve optimal performance.
Photos By Mark Harmel
Mar 1, 2006