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Endocrinology (including Diabetes)/Managing bld glucose while running competitively with Type 1 diabetes


QUESTION: Hello. My son is a 17 year old type 1 diabetic. He was dx almost 2 years ago. He is on an insulin pump and is very compliant and competent in managing his diabetes. His insulin needs are still changing as he is still growing and maturing so his setting are fequently changing. My son is about to start his senior year in HS. He is a 3 season athlete, running cross country, winter and spring track. He is having a big problem managing his blood sugar during runs, especially long fast runs. His dr has made several recommendations but what generally worked in the past no longer works. Currently, he is suspending one our prior to and during the run, having carbs ( Gatorade or chomps) and an extend bar prior to a run, giving  40 percent of a typical bonus one hr prior to a run. He also keeps an 80 percent temp basal for 10 hrs post exercise.  Last night he started the run at 220   and still dropped to 64 one and a half miles in. Then after the run his sugar is high again!He is depressed and frustrated. I have been on the computer and phone for 4 hrs trying to find someone in the area with expertise in this area. We live in Northern NJ. Any advice or referrals you could make would be appreciated.

Thank you!
Barbra Seltzer

ANSWER: Barbra,
  It is difficult to keep making adjustments from year-to-year as things change for your son.  It sounds like he needs a smaller bolus before his run, or maybe he can get by without one at all and just eat less (most cross country races are only 5K, meaning he doesn't need that many carbs during it).  Usually, having less insulin on board during the event (while still having a small amount) will help prevent lows during events lasting less than an hour (longer events require more food intake).  It's easier to correct a high afterwards than get low during the event and have that affect his performance.  He could just try suspending his pump during the run and not before and not take a bolus at all.  Boluses are just a lot of insulin at once compared to basal insulin dosing.
  There are a lot of runners out there that may be able to make additional suggestions.  Also, if you haven't read "Diabetic Athlete's Handbook," that may help explain some of the physiology better and give some athlete examples.  You can find out more info about that book on my web site at  Hope this helps.  Sheri

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QUESTION: Hi Sheri. Thank you so much for your prompt response . I think Jacob is already doing everything you suggested except he does Bolus if eating or if high prior to a run but at 50 percent if within 2 hrs of exercising. Are you suggesting he not bolus at all prior to exercise? And if so within what time frame? We visited your website and plan on ordering your book. Do you have any contact info for diabetic runners who might be able to help us ?
Thank you again!


  I would not have him bolus within two hours of running, given the low he experienced at his last meet.  If he does that, he may not want to suspend his pump quite as early, though.  I know a few marathoners.  One is Missy Foy, who has a running blog at  You may try contacting her through her site.  Also, the group called (web site at same) is a community of many diabetic athletes.  Sheri

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Sheri Colberg, PhD


I am an exercise physiologist with a PhD who specializes in diabetes--as such I CANNOT answer general questions about other endocrine problems as I am neither an expert in all areas of endocrinology nor am I a medical doctor. My expertise lies in answering questions about diabetes (of any type) and physical activity, so please limit your questions to those areas. I can help you if you want to begin exercise or if you're already a diabetic athlete, and I am prepared to respond to questions about physical activity to which even your diabetologist may not know the answer. I can give suggestions about changes in your diabetic medications that differing types and intensities of exercise may necessitate, but I will have to refer you to your regular health care team to get final approval to make such changes. I can also answer questions about physical fitness, exercise metabolism, prediabetes reversal, and prevention of type 2 diabetes and diabetic complications.


I have both personal and professional experience in the areas of diabetes and exercise/physical activity. On a personal level, I have had type 1 diabetes since 1968, and I have been an avid exerciser since I was a child. Professionally, I have been conducting clinical studies on diabetes and exercise since 1992, largely with funding from the American Diabetes Association. I am also the author of 8 books related to diabetes, exercise, and more: The Diabetic Athlete (2001), Diabetes-Free Kids (2005), The 7 Step Diabetes Fitness Plan (2006), 50 Secrets of the Longest Living People with Diabetes (2007), The Science of Staying Young (2007), Matt Hoover's Guide to Life, Love, and Losing Weight (2008), Diabetic Athlete's Handbook (2009), and Diabetes? No Problema! (2009).

I am a Fellow of the American College of Sports Medicine, a professional member of the American Diabetes Association (and professional volunteer for the ADA), and a former member of the Board of Directors of the Diabetes Exercise & Sports Association.

I have published research and review articles in the following journals and magazines: Diabetes Care, Diabetes, Journal of Diabetes & Its Complications, Diabetes Self-Management, Medicine & Science in Sports & Exercise, Journal of Applied Physiology, The Physician and Sportsmedicine, Journal of Clinical Investigation, International Journal of Obesity, FASEB Journal, The Diabetes Educator, Journal of Physical Education, Recreation, and Dance, Clinical Exercise Physiology, Clinical Diabetes Reviews, Insulin, ACSM's Health & Fitness Journal, Biomechanics, On the Cutting Edge, Diabetes Technology & Therapeutics, Microvascular Research, Drug Benefit Trends, ACSM Certified News, Diabetes Health, SportEX Health, Diabetes Focus, Diabetes In Control, dLife-For Your Diabetes Life, Pediatrics for Parents, and My TCOYD (Taking Control of Your Diabetes) Newsletter. I have also been interviewed in myriad other magazines, such as Men's Health, Men's Fitness, Diabetes Forecast, Countdown Magazine, Joe Weider's Muscle & Fitness, Health, Tidewater Parent, Barron's News, Diabetes New Day, and Newsweek International.

I have an undergraduate degree (1985) from Stanford University, a Master's degree in exercise physiology (1987) from the University of California, Davis, and a Ph.D. (1992) from the University of California, Berkeley, in the same field. I also spent two years in an NIH-funded postdoctoral research position in endocrinology (studying obesity, diabetes, metabolism, and exercise) at the University of Pittsburgh School of Medicine (1993-1994).

Awards and Honors
Fellow, American College of Sports Medicine (FACSM) - 1996 Old Dominion University Darden College of Education Young Investigator Grant Award 2003 Honor Society of Phi Kappa Phi, Old Dominion University Chapter 2004-Present Great Women of the 21st Century by the American Biographical Institute 2005 Edition Old Dominion University Darden College of Education Largest Research Grant Award 2006 Old Dominion University Darden College of Education Publications Award (for greatest number) 2006 Saint Louis University, The Max K. Horwitt Memorial Lecture Distinguished Lectureship Award 2008 Old Dominion University Darden College of Education Publications Award 2009 Old Dominion University Darden College of Research Grants Award 2009

Past/Present Clients
I have consulted for numerous groups, including Can-Am Care, Numera|Social, California Commission on Peace Officer Standards and Training(about candidates with diabetes), Animas Corporation (an insulin pump company), Therasense, Inc. (makers of the Freestyle blood glucose meters), Council of Healthcare Advisors, and the City of Chesapeake (Virginia) Health Department.

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