At the beginning of this year, I decided to take up running again—something I hadn’t done since running the London 10k with my flatmates nearly 20 years ago. As a 43-year-old with Type 1 Diabetes, I knew this wasn’t going to be as simple as lacing up my trainers and hitting the pavement. Apart from my unfit body, one of the biggest challenges I faced was managing my blood sugars during and after exercise, and figuring out how to get the most help from my Medtronic 780G insulin pump and sensor combo.
Over the last 8 months with the help of a well-timed academic paper and lots of trial and error, I slowly started to get the hang of it. I've safely run hundreds of kilometres in training runs, completed the 10k Race for Life in July and I'm gearing up to run a half marathon in October. My sugars haven't been perfect but they have been manageable and I've stayed out of trouble on the hypo front, which is a big win from my point of view.
This post is my attempt to share what has worked well for me in the hope that it might be helpful to anyone else thinking about running while also managing their type 1 diabetes along the way - just remember I am not a doctor and this isn't medical advice! Read on for all the things I’ve learned to think about when running with the Medtronic 780G, and my wish list for future pump improvements to make it a better running companion.
At the start: diabetes + running = a mess
I kicked off with a 5km Parkrun in the first week of January, just to see if I could run that far. I surprised myself by being able to run it all, slowly and uncomfortably. I stuck to a maximum 5km distance for the first few months. This meant that at the beginning of my running journey I was running for about half an hour at a time and I was super conscious about avoiding hypos. I’d overcompensate with carbs before running, leave my pump on the "Temp Target" (exercise mode) for too long (sometimes on purpose, sometimes forgetting to turn it off), and end up spending hours after my run with stubbornly high blood sugars.
Figuring it out: trial, error and an academic paper
A lot of the advice about exercising with diabetes is quite generalised and I didn't find it that helpful for the problems I was facing. I knew it was better to minimise insulin on board before a run and to set a temporary exercise target (but when and for how long?). What about eating before a run? How much do I eat, what do I eat, when do I eat it and do I bolus anything for it?
It felt like a constant guessing game, and it was frustrating - exercising is meant to be good for people with diabetes, right? I wasn’t sure how to strike the right balance between managing my diabetes and actually enjoying my runs.
As if by magic, I was searching online for help and I came across a newly published academic paper that was perfectly named: Exercising Safely with the MiniMed 780G Automated Insulin Delivery System by O'Neal et al. (2024).
I owe the writers of this paper a big thank you as their paper was not only about theory, they provided practical strategies for using the 780G during exercise which have been a game changer for me.
Here’s what I do before, during, and after running to manage my diabetes—and how I incorporate some key insights from the academic paper that helped me along the way.
Before I run - exercise settings, maybe a snack
Minimising Insulin on Board (IOB) before exercise
The paper emphasises minimising insulin on board before exercise. Having too much insulin active in your system increases the risk of hypoglycaemia. O'Neal et al. recommend reducing meal boluses by 25-50% before exercise and avoiding large meals 1-3 hours beforehand.
What I do: I pretty much always time my runs for first thing in the morning before I eat breakfast. I put my exercise gear on, have a cup of tea, do some warm up stretches and then head out.
Using the Temp Target (Exercise Mode)
The Temp Target should ideally be set 1-2 hours before exercise. If that’s not possible, setting it 20-30 minutes in advance still helps mitigate lows. When the Temp Target is on, the pump doesn't do bolus autocorrections, but it does adjust the basal rate in response to what is happening with your blood sugars.
What I do: I put the Temp Target setting on when I wake up so it is more like 30 minutes in advance of the run, and this generally works fine for me.
To snack or not to snack?
The paper highlights the importance of considering your pre-exercise blood sugar levels before deciding whether to have a snack. If your blood sugar is already in a safe range (e.g., between 7-10 mmol/L or 126-180 mg/dL), a snack may not be necessary. However, if you’re on the lower side, a small snack can help prevent blood sugar dips during exercise, and importantly, it recommends not announcing the snack to the pump (i.e. don't bolus for it).
What I do: I follow this guide and only have a snack before I run if my blood sugar is under 7.0 mmol/l. It's important to time this right though, about 15 minutes before starting the run. If I eat it too early I will start going higher, and if I eat it too late it doesn't get digested until after the run and will cause a spike.
During the run - vigilance, fuelling, avoiding hypos
Once I’m out the door, my focus is on keeping my blood sugars stable without disrupting my pace. Here’s what I’ve learned about managing diabetes mid-run:
Blood sugar vigilance
I don't have an Apple watch or a phone that works with the Medtronic app so I need to keep my pump handy to check my sugars. I've become quite good at unclipping my pump and waking up the screen without stopping my runs. Occasionally my pump stops communicating with my Guardian 4 sensor and I don't get any blood sugar readings - this happened on my 10k race - so I carry a finger pricking kit on longer runs just in case.
Hypos during exercise are slow to recover from
One of the hardest things to manage is low blood sugars during exercise. I’ve found that hypo treatments are slow to work while I’m exercising—they don’t kick in until after the session ends, and then there’s often a big spike. Because of this, avoiding hypos has become my top priority when running.
Basal rate adjustments can be a double-edged sword
One of the lessons I’ve learned is how the 780G adjusts basal rates, even in exercise mode. When you set the temp target, it raises your blood sugar target to prevent lows, but if your blood sugar starts to rise, the pump can still automatically increase basal insulin. This can happen if you’ve eaten a pre-run snack or if adrenaline from the run kicks in.
The issue is that the 780G doesn’t show how much basal insulin is being delivered in real-time; it only displays insulin on board (IOB) from boluses. There is a colour indicator on the graph which shows the basal being delivered but it's not quantified. This can make it tough to know what’s going on, leading to unexpected highs or lows during or after a run.
What I do: I suspended the pump before a recent run to stop it from giving me too much basal insulin after my pre-run snack. That worked out OK, but I was mindful of turning the pump back on again at the end of my run and I kept a close eye on my blood sugars.
Carbohydrate supplementation
For exercise lasting longer than 40 minutes, the paper suggests 30-90 grams of carbs per hour to prevent lows. I’ve found this especially helpful during longer runs when I need to keep my energy up without spiking my blood sugar.
What I do: I carry little packs of Skittles with me on my runs, and if I'm planning a longer run I will have some when I get to about 30-40 minutes into the run, then every 20 or so minutes after that. I find little and often works quite well. I am also experimenting with energy gels (so far they are like ingesting flavoured wallpaper paste, I'm not a fan). For me, it's a lot easier preventing a low than it is to fix one that has already happened on a run, so that's what I try to do.
Stop/starts can lead to injury
Managing blood sugar issues mid-run sometimes means stopping to check my pump or deal with a low, but I've noticed that the more I stop, the more likely I am to injure myself. The breaks in momentum can affect my stride and make me more prone to strain. Learning to minimise these interruptions and keep a steady pace has helped me avoid injuries and improve my performance overall.
After the run - spikes and sensitivity
Post-run blood sugar spikes
I learned early on how to manage post-run spikes. It's quite common for me to experience a post run spike, whether that's because of hormones or delayed digestion of the food I ate before or during the run. The 780G doesn’t automatically bolus for these spikes when the Temp Target is set, so I switch it off as soon as I get home after a run. This helps because bolus corrections can kick back in, even though they sometimes take a few hours to bring my sugars back down again.
Avoiding evening lows
With my post run spikes sorted out I have to switch to being vigilant about going low later in the day. After a run, insulin sensitivity tends to increase. The paper suggests reducing post-exercise meal boluses by about 25%, which helps avoid post-run lows.
What I do: I find my insulin sensitivity is greater in the evening after a morning run so I ease off on my dinnertime insulin. By that time any post run highs have usually stabilised so I feel confident doing this.
If I could wave a magic wand - my 780G running wish list
While I’ve learned to manage running with the 780G, there are still a few things I’d love to see in future versions of the pump. Here’s my wish list:
Pre-programmable Temp Targets Being able to pre-programme a Temp Target to start automatically at a set time would be great for early morning runs where it's impractical to set it early.
Bluetooth integration with audio stats Imagine getting real-time blood sugar updates directly into your headphones alongside other running stats like pace and distance. It would save me from fiddling about with my pump mid-run and help me stay focused.
Access to the Simplera Sync The next generation sensor, which is more streamlined and quicker to replace would be a huge improvement. I've been on a few runs without a sensor because it wasn't ready in time after a changeover - frustrating!
Smaller and lighter pump The 780G can feel bulky and bouncy during a run, depending where I clip it. A smaller, lighter version would make running more comfortable and less distracting.
Running with type one diabetes is more complicated but I still love it
I’m so glad diabetes hasn’t stopped me from enjoying running. The journey has been rewarding so far, and my training runs have helped me build the confidence to run longer without blood sugar issues holding me back.
If you’ve got tips or strategies for running with the 780G, or if you’ve figured out any great fuelling strategies for long-distance runs, I’d love to hear from you!
