Running Diabetes: The Pump

I am Type 1 diabetic runner. Which means that I am insulin dependent which I receive in specific doses via an insulin pump. I am not going to cover what diabetes is or the difference between the types and other general stuff here. There are plenty of really good information available, you can take a look in sites like The American Diabetes Association, JDRF (Juvinile Diabetes Research Foundation), WebMD, TuDiabetes, DLife and others. Here I will like talk about how I manage my sugars and diabetes while training, running and racing. For that purpose I have divided the topic in several segments, from basic to some running details.


The Pump


The pump I use is a Medtronic Minimed 530, with the CGMS (Continuous Glucose Monitoring System). There are other brands in the market, that can produce/have similar features. Do your homework to find what works best for you. I have been a pump user for the last +10 years and my A1C and glucose control has been much better ever since.

Now, the caveat, the amount of information you get and you need to use is vast. (CGMS, Meter measurement, Hydration, Rest state, Stress level, health, weather conditions, others) And the possible adjustments and variations when you take in consideration type of food intake can take you into a journey of insanity by itself. But once you get the hang of it, with some trial and error (A safe trial and error) it becomes very useful and good for your life. It is very important that during your training runs you learn to quickly identify the cues that you body will provide at different conditions. As a example once my sugars starts to go up outside my running range and I am doing a tempo run, pushing a run or hard workout, the muscles on my legs start to feel like burning, like they are on fire. In the other hand a rapid descend in sugars will make me feel light headed even if the sugars by itself are still with in range.

NOTE: Keep a running log and write down a few of the details of the runs. Even if you never go back a read the notes, the mere fact that you are writing it down will help process and remember the information.

Race preparation:

The Pump dynamics preparation for an event starts at least a week before, I start thinking about how long do I have with the current infusion set and reservoir. In my case, I use the infusion set up to seven days with a the reservoir lasting around 3 to 3 1/2 days before I have to change it. I always try to make sure that the infusion change lands a day or two before the race. That way the adhesive will have full strength to remain attached during the event. Also this provides enough window of time to make sure that the insertion of the infusion set was successful, effective and working fine before the event.

I keep an eye on how much I have left in the reservoir to make sure I will have enough to handle the race and post race with an estimation for adjustments.

NOTE: Use the information from the pump to help you out in determine how much insulin is in the reservoir. Start being conscious around how long the reservoir last with normal utilization and plan ahead.

Race day:

One thing I notice is that no matter what event it is, I always get nervous. That nervousness somehow affect my sugars, but with a standard routine I can control it better in the early hours of the morning and at least have a great running start. I do have a mental table with my common actions based on the sugars readings, I call that table my running sugar table.

NOTE: Your rehearsal training runs do not start when you start running. They start hours prior and perhaps the day before the training run. Make it a habit during every long run if possible.

Depending of the weather forecast, I will bring an empty plastic sandwich bag with me for just in case. My pump is water resistant, but not water proof. So, running a few hours in the rain might cause some problems, I need to prevent that.

Now, I have not have any problems during any race or training run with the pump itself malfunctioning. But, one summer, after a few very sweaty runs, the pump at that time malfunctioned later in the day with one of the buttons getting (I believe) shorten out due to the humidity collected during the runs. Medtronic quickly send a replacement and I have not any other issues in the past years with it.


I have been very fortunate that my pump have not failed and the infusion sets have lasted the duration of the events.

BASAL: For adjustments, during the early running month I played with reducing my basal rate 50%, then after that not working out so well, 25% quickly monitoring my sugars before, during and after. This action of lowering the basal came due to the early concern and fear for lows during the runs.  More recently I do not make adjustments to my basal rate, keeping a good eye to all the cues that my body and the CGMS provides me. Making adjustment only if necessary.

BOLUS: For bolus during the event/race I have been very careful. I never do the full dose to cover the carbs I consume during the events. Depending of the status of the sugars readings I will do 50%, 33% or none.

[vtftable cols=”{0}0-3:d9ead3;{/}”] {f1}Carbs;;;{f1}Normal;;;{f1}50%;;;{f1}33%;nn;
25g;;;3 Units;;;1.5 Units;;;1 Units;nn;

The key is to continuously monitor your sugars. I try to remember to every two miles do a quick CGMS check if not feeling optimal and if optimal feeling pace every 40min the time I take my fuel.

NOTE: These values are based and different to each individual. The key here is to learn, monitor, record and plan. Talk to your doctor and endocrinologist about your approach and reasoning. This is a continuous improvement process.

Event requiring away travels:

Nothing much special that any other long trip. Bring you extra supplies with you. At least one extra infusion set to what you normally will bring on a vacation trip for that timeline.

Final Notes:

I will continue to update this post with new relevant information and other details that I might have missed. Also coming up I will write more information around other areas like CGMS, Fueling, Training Plans & Runs and others in this series of Running Diabetes.