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Physical Activity Q&A with Dr. Sheri Colberg, Part 2

Apr 7, 2010

Sheri_ColbergDr. Sheri Colberg, Ph.D, FACSM, continues her series on your most frequently asked questions this week.


Q: Dr. Sheri, what is the bottom line recommendation for a 41-year practicing Type 1 who wants to burn fat and build muscle? What type of exercise(s), intensity, and frequency will help me do this? I have been doing cardio or aerobics (elliptical and treadmill) for 15 min and weight resistance training (upper and lower body) for 90 min. My weight varies between 170 and 180 with time. I would like to get to 185 and hold it there. F.


A: F, the best way to build muscle at any age is with higher weight, lower repetition weight lifting (no more than 8-10 reps with the heaviest weight you can do that many times, at least in the last set of however many you do).

How often are you doing the 90 minutes of weight training? Optimally, it should be no more often than every OTHER day, or at least you should alternate upper body one day with lower body the next to allow adequate recuperative time. That’s all I can suggest without knowing more about your routines.

Q: Thanks for the feedback. I work out twice a week, Tuesday and Thursday morning. I don’t do 3 days a week because I need more time to recuperate and recover. I am active on the days off with outside yard work and around the house activities. My plan is to do more cardio on Monday, Wednesday, and Friday mornings on the ellipitical machine.

I need to change my workout routine as you suggested: lift heavier and fewer reps. Now I am doing 12 reps with a weight that I can just barely complete the exercise with. It’s interesting that some days I can just about finish 12 reps with a certain weight and on other days I can add weight and complete12 reps very easy. Do you know why that is? F.

A: F, we all have days we feel strong and others that we feel weaker. Push when you feel strong, and coast when you don’t feel that way. There’s really no need to push hard on the days you don’t feel up to it as you might end up injuring yourself. As long as you keep doing it, you’ll move forward with your training goals.

Q: Dr. Sheri, I would love to exercise, but I have needed a knee replacement for about three years and because I have had bypass surgery on that leg they didn’t want to operate until they had to. It got bad enough, they scheduled surgery and before the date came up I found out I had lung cancer and started chemo. I am in remission right now and they have given me a couple months break from chemo. Are there any exercises that you could recommend I take with these issues? I need to exercise! E.

A: E, without knowing more about your unique situation, I would guess that you could still safely participate in upper-body resistance training. In addition, you may be able to do some non-weight-bearing aerobic work, such as walking in a pool, aquatic exercise classes, swimming, and chair exercises or chair dancing. Depending on how your knee feels you may even be able to do a recumbent stationary bike or an elliptical strider machine, which is pretty gentle on knees. Doing any kind of activity that you can is sure to help with preventing further muscle atrophy and increasing your energy levels. Try out these things until you find which ones work for you.

Q: I have a question for you that may or may not be related to this topic, but I’m going to ask anyway. Following long (2-3 hours) or intense aerobic (running or cycling) workouts, I’ve been experiencing blurry vision. This blurry vision is the same symptom/feeling when my blood sugar gets extremely low (below 30). However, when I test, it’s usually in the 130-160 range. So I’m confused.

I think this might be glucose-related because the blurry vision is exactly the same feeling/symptom as when my blood glucose gets really low. It’s not life threatening by any means, but it would be nice if it didn’t happen. Do you have any ideas on what might be causing this? Or more importantly, how do I make it go away? Thanks in advance! G.

A: G, I really don’t know what is causing your post-exercise blurry vision. Sometimes rapid changes in blood sugars can cause visual changes, but I don’t know if that is the case with you. I would suggest that you simply continue monitoring your blood sugars like you have been doing. If this symptom persists, you may want to check with your ophthalmologist to see if he/she has any ideas.

Q: I’m a Type 1 and I’ve used your book The Diabetic Athlete in training for triathlons. THANK YOU for writing this book. After a two year layoff from exercise, I’m working out again and finding it hard to shed the 25 pounds I’ve gained. I’ve been working out for about 3 months now. Perhaps I’m getting older and my metabolism is changing (I’m 39 now).

My question is this: How do I ensure that I’m fueling my recovering muscles without eating a lot of food? I’ve lowered my post workout basal rate which controls my blood sugar. However, I still get really hungry and end up eating more food than I’d like. Should I just know that I’ll be hungry while losing weight? G.

A: G, Thanks for the comments about my first book.  A fully expanded and revised version of that book now called, The Diabetic Athlete’s Handbook was released in November 2008. I’m sure that will be helpful to you as well.

As for your issues with losing weight, changes in metabolism are mainly due to losses of muscle mass. When you start to gain some more muscle from exercising consistently, you may not find that it has changed that much in just two years. In any case, you do need some carbs to properly refuel, but try to keep the overall levels of insulin that you have to take as low as possible to help with your weight loss. It’s virtually impossible to lose much weight if you’re having to take high doses of insulin. Focus more on increasing your intake of quality protein sources (e.g., egg whites, lean meats, fish, and soy) and moderate your intake of carbs. You won’t go hungry doing that, either.

Q: I have been using the Glycemic Index in my meal plan and it seems to work for me with some foods. I use pumpernickel bread for sandwiches in place of white bread and for the most part the 2 hr post-prandial glycemic spike is lower. Of course what is on the sandwich is important also. So many variables!!!

I think the timing of my meal bolus is something I need to work on. Sometimes giving the insulin a head start by taking my bolus 15 to 20 minutes or more before I start eating seems to have an effect on post-prandial glycemic spikes. I would appreciate your comments on insulin bolus timing.

A: F, giving the insulin bolus a headstart is an excellent idea, particularly if your blood sugars are elevated at all at the start of your meal. The only danger is if you’re eating really low GI foods and the insulin hits your system before the food does. It just takes a little practice to time it out right for different meals. Another option is to give part of your normal dose 15-20 minutes before and the rest afterwards when you have a better idea of exactly how many carbs you ate.


If you have any physical activity, fitness, exercise, or nutrition questions for Dr. Sheri Colberg that you would like to see answered in my next column, please e-mail them to sheri@shericolberg.com.

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