Join Dr. Marina Basina, MD, to answer all your questions regarding adjunct therapies to insulin and how they can impact exercise! The conversation may include discussions on GLP-1s, SGLT-2 inhibitors, Afrezza, mini-dose glucagon, and exercise. She can also discuss tips and tricks around AID and exercise (specifically Loop, DIY).
She will be answering questions live for 1-hour on December 16, 2025 at 9AM PT / 12PM ET / 6PM CEST. The discussion is open now, so you can post your questions ahead of time if you are unable to join live.
Hello! Here is a topic of discussion from one of our community members submitted via email:
“I am on a tiny dose of tirzepatide (1mg weekly) and I find that I am dropping very quickly when I exercise despite not much IOB, whereas it used to take about 1/2 hr unless I had too much IOB. Even on that tiny dose, it has had a remarkable affect on my blood sugars and insulin needs.”
Thank you so much for any thoughts and expertise you can provide on this topic, Dr. Basina!
I am Marina Basina, an adult endocrinologist at Stanford University and serve as the Medical Director of Inpatient Diabetes. My clinical and research interests include type 1 diabetes and pregnancy, automated insulin delivery systems, and the prevention of diabetes complications. I am a board member of Breakthrough T1D and serve on the medical advisory boards of several community organizations, including Beyond Type 1 and Sugar Mommas Type 1 Diabetes. I am also a principal investigator on multiple clinical trials.
I am grateful to have received several teaching awards, including a Master Teacher Award, as well as an award for excellence in clinical care.
Please feel free to ask questions—I will do my best to address them during the next hour. If time does not allow, I will continue responding over the coming days.
How often do you see adjunctive therapies being used in your clinical practice with people with Type 1 diabetes and do you see that their exercise management changes?
thank you for joining and thank you for the question. There are no studies evaluating the risk of low blood sugars with exercise in individuals with type 1 diabetes using GLP-1 medication class. There is a theoretical concern that GLP-1 agonist medications can contribute the loss of glucagon counter-regulatory response to low blood sugar, and therefore, contributing to hypoglycemia. Some of the tips (from my clinical experience, no clinical trial data available on this topic): exercise before the meal when you have lower insulin concentration in the body to suppress liver and muscle release of glucose (from glycogen stores breakdown), eating a small protein containing snack, reducing basal rates or starting an exercise mode 60-90 minutes before exercise. You can also try starting with resistance exercise before doing cardio type of exercise. For the low blood sugar correction, use chewable pure sugar source, such as glucose tablet, gummies, Glow dextrose to get sugar absorption faster from the mouth rather than relying on the stomach absorption because it can be delayed due to the use of GLP-1. Please let me know if I answered your question and if you have any additional questions. thank you
welcome to DiabetesWise and thank you for posting the question.
I use adjunctive therapies for individuals with type 1 diabetes very frequently in my practice. Insulin given via injections or subcutaneous infusion can’t fulfill all the physiological body’s requirements. Adjunct therapies help with some of the missing steps. I use mostly GLP-1 agonist class and metformin, sometimes SGLT-2 agents. There is some increase in the risk of diabetes ketoacidosis (DKA) with the use of these agents, so careful insulin dose adjustment and education on DKA prevention is needed. There are ongoing trials of the use of GLP-1 and SGLT-2 in type 1 diabetes, and I hope these classes will get approved soon because they offer many advantages in addition to the improvement in glycemic control. Please let me know if I can answer any specific questions. This is one of my favorite topics that I can talk about for hours
Thank you! How about Afrezza with AID use, do you see this happen in your clinical practice, if so do patients find it successful in managing exercise?
I usually take a very small dose of insulin with the carbs I eat about 30” before exercise so maybe I need to decrease that dose even further. I also use a 50% basal rate, but I probably should also have a higher target with exercise I do use glucose tabs or Glow gummies and they don’t absorb as quickly now either. The Glow gummies are absorbed in the mouth - I might be eating them too fast!
yes, I use Afrezza in AID. It might be particularly helpful in the management of AID and exercise due to its fast onset and short half life. As an example, if exercise is planned to be a couple of hours after the meal (if this the best time for a person to exercise), use of Afrezza helps with reducing post-meal spike and leaving minimal insulin on board before exercise. Other possible scenarios is resistance exercise/weights that can raise blood sugar early in the exercise but lead to low blood sugar after exercise. Using Afrezza can help with the initial rise of blood sugar and avoiding insulin on board when blood sugars start coming down after the exercise. There are many other possible scenarios when Afrezza would be helpful.
Hi Dr. Basina! Thank you so much for your time today! I have a question about GLP-1 use. I’ve read before that there is a sort of maximum “time limit” on the effective use of GLP-1 medications of around 5 years. Could you help me understand why that is and also what the options are for people who then reach that 5 year mark on a GLP-1 medication? Thank you so much in advance!
thank you for this follow up question. And sorry about your troubles with popups. I will let the admin know.
If you are using an automated insulin delivery system, consuming carbs 30 minutes before exercise may lead to automated bolus or increase in basal rate by the algorithm in response to the sensor glucose rise. This can cause subsequent low blood sugar. If your blood sugar is between 126 and 180 mg/dl (per the recommendations from consensus statement) and you have no insulin bolus on board, no additional carbs are needed for the exercise, especially if you started exercise mode or 50% basal rate reduction 90 minutes before exercise. Chewing slower might help with the sugars to be absorbed from the mouth.
Please feel free to send any follow up questions, thank you
One advice is to do a short exercise after each meal, even 5-10 minutes of brisk walking has been shown to reduce post-meal spike and decrease the number of insulin units needed to cover carbs in the meal, also to help with achieving one-hour glucose target of 140 mg/dl (pregnancy target). Exercise insulin management requires careful insulin dose titration and depends on the trimester of pregnancy because of the rising insulin resistance during pregnancy.
this is a really great question! Unfortunately, it has not been well studied. You are correct, there is some evidence that the effects of GLP-1 can plateau in about 4-5 years. This is mainly the effect on the weight loss but the studies have not investigated the loss of the effect on glycemic control and/or reduction of heart disease and kidney disease risks. I usually advise patients not to titrate the dose fast, but remain on a low dose or current dose, as long as weight continues to slowly come down or stable, then increase if there it starts trending up or you see the effect on appetite reduction is wearing off. You can also spread the injections to every 10-14 days if everything is stable and you are in the maintenance phase of the weight. I wish I can provide more information but the data is limited at this point. Thanks for the great question.
Thank you for taking the time to answer all of the questions today! Do you know what impact mini-dose glucagon has, especially if used around exercise and if it is being used in conjunction with an AID system? Also, what are you most excited about with the growth of new adjunct therapies in the future? I think we need more research on many of them!
interestingly you asked the question about mini-glucagon! Thank you for asking it. There is a recent study that was published on the use of mini-glucagon for low blood sugar prevention. The study did show that if mini-glucagon was given 5 min before exercise, helped with exercise-associated hypoglycemia reduction compared to placebo. In this study, the participants were fit and followed regular exercise routine, so we don’t know if the effect would have been different in someone who might be just starting an exercise program. Study participants were on insulin pumps and not multiple daily injections, so we don’t know if mini-glucagon would have the same effect or action in individuals using injections.
my clinical tips: it can be used if starting aerobic exercise and blood sugar is under 126 but insulin bolus on board, the timing of the previous bolus needs to be taken into account.
Sorry, no simple answer to this question, I think this should be individualized
