Training with Type 1 Diabetes

i would also suggest getting a Dexcom along with the insulin pump, but i would also suggest setting it up with “nightscout”, that way the Dexcom (or other CGM’s for that matter) can be monitored directly on a garmin bike computer/smartwatch/etc with a Connect IQ app… the following has been a real gamechanger for me since i can monitor everthing just by looking at my gps, i got a custom datafield with power, cadence, heart rate and bloodsugar - i can recommend going that route if its an option ofcourse

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Hey!
I’ll start with the age old caveat, what works for me might not be applicable but my experience as a T1 cyclist (used to race) would be;

For Aerobic workouts; Have any fast acting insulin out of your system before you train. By this I mean I do all my TR workouts in the evening. I have my lunch (usually high carb) no later than 1pm. This leaves 5 hours for the insulin to be absorbed. Depending on brand fast acting can have residual effects for 6 hours after injection (even fast acting).

I’ll then snack on something low GI an hour before I train to bump up the BG’s accepting this might take me a little higher than recommended.

The work out usually then brings me back to normal. And I have 30g of dextrose ready in a bottle just in case.

If I’m going out in the morning I don’t have any insulin with food but am out the door within 30 mins of eating.

Anerobic; glycogen dump from the liver will make BG’s skyrocket.
I don’t personally correct for the high with insulin as it’s a hormone response rather than food response. Usually sorts itself out. But I do an extended (15 min) cool down as if you stop straight after efforts you’re still releasing the sugar from the liver.

Recommendations for kit are helpful but your biggest bang for buck is understanding the science behind your condition. Tech is great but only if you understand how to get the best out of it. Think from a cycling perspective best kit might give you watts but training the right way will give you more.

BUT most importantly don’t let it stop you doing what you want to do. My best life experiences have come because I’m a diabetic and it opened up opportunities I would never have persued otherwise.

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I couldn’t agree with any of this more. This should be required reading for any diabetic athlete.

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Sorry for the late reply! But better late than never.

The insulin pump is a great first move. It improves hba1c, and I would like to reiterate what others have said here. Next step, for both better control AND workouts, is the continuous glucose monitor. Dexcom and Medtronic have them. I personally use the Medtronic closed loop insulin pump. The Novo nordisk team, an all type I diabetes pro cycling team has the dexcom with insulin pumps.

There are sports specific diabetes training camps. Short, one week, camps to help diabetic athletes fine tune their performance and MANAGEMENT of glucose during exercise.

I also recommend the Type I diabetes facebook group Race T1. They host online zwift competitions and social rides. The riders are a WEALTH of information and experience.

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I was exactly the same as your brother diagnosed as Lada type 1 at 30 years old. I am an MTB guy and most of my races are sub 1.5 hours although I do occasional marathon styles 3-5hrs. I am using the Medtronic 670g in automode. I start temp target 1-2 hours before a ride and end it 1-2 hours after after completing ride. For the more endurance style rides I take in 40-50 grams of carbs per hour. Also adequate hydration prior to riding is essential. Using the 670g I really haven’t had any issues comparing to my ride days prior to being diagnosed.

I have had type one for over 10 years now and do not have a pump and have no intention of getting one. I just can’t imagine having something attached with a tube 24/7 and would much rather take multiple injections a day. That being said pumps are amazing tech and some people love them (I have considered trying out an omnipod). I currently have a Dexcom G6 CGM and this is a gamechanger. My dexcom is also paired with garmin connect so I can see my BG on my garmin as long as I am in an area with cell signal.

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For what it’s worth, I know it’s only one opinion, but my wife used to really dislike the tubing but dealt with it. Then she tried Omnipod on a whim and has loved it ever since for it’s simplicity and lack of tubes. Omni has has a free trial kit that you could always try out too without needing to pay.

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A little inspiration for your brother and those of us with diabetes :blush:

I am new to the forum and realize this thread has been quiet for some time, but here goes anyway:
I am a longtime cyclist with borderline Type 2, have been able to get my A1C down through diet, and am using a Dexcomm to monitor my sugars. This has been a game changer (it’s like a powermeter for food and my body). On more intense rides (I bike in the morning) my blood sugars will go over 200 but then quickly drop once I stop riding or after about 90 minutes (when I’ve exhausted the glucose that my liver has dumped). FWIW: an hour after stopping I’m back to about 90-105 blood sugar level, and stay pretty consistent in that range throughout the day, as long as I manage my diet properly. I’m wondering if others have this same issue, if there is anything to do about this, and how high is too high? My endocrinologist says I’m fine, but he’s not an endurance athlete. I’m not asking for medical advice here, but do want to know how others manage this. I’m sure that this was going on for me for years, before the Dexcomm, but now that I have this information, I want to figure out how to use it.

Hello, I am newish to the forum and Type 1 for about 18 years now. Thanks for bumping the thread, otherwise I may have never seen it!

I use a pump and CGM (Dexcom) with a smartwatch to monitor my glucose levels during rides/races. I often start my rides on the high side (200’s, sometimes 300+ but not on purpose) because I don’t want to be loaded with insulin while I am out on the bike. It’s a little different for T2 diabetics so keep that in mind. The CGM was a game changer as it enables me to monitor my BG during a race without needing to stop and prick my finger. I use a smartwatch to see the readings since my Wahoo does not have the same capabilities as a Garmin (I prefer the watch over a head unit display anyway).

For races over 3 hours, I will usually ditch the pump and just monitor my BG. For 3+ hour events, I have to pack the pump with me. My biggest worry is to have a low BG during exercise, so I am known to carry way too much food with me. I had a seizure one time due to extremely low BG, and it was not fun!

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Hey there, even tho i am a type 1 i can tell that its quite normal to see bloodsugars going to the higher side during more intense work is normal. The reason this happens is basically because the more intense rides causes your body to produce more cortisol and adrenaline which in return will raise your bloodglucose levels, its very normal.

I run a dexcom g6 myself and here is an example on how different ride intensities affect my bloodglucose:


The picture on top is some endurance riding followed by Pettit +1 and Obelisk, bloodsugars remain normal all the way through the ride, and on the picture below that is a warmup followed by the Ramp Test followed by endurance riding with a mate on Zwift… as you can see, after the ramp test were the body is quite stressed the bloodsugars just goes up up up despite not eating anything (and actually having abit more insulin than i normally would when riding) and after some time as the stress levels comes down again so does the bloodsugars (i am not bolus’ing aka taking any insulin to get it down, it just starts to decrease again on its own as i ride). Thats just the daily struggle of trying to predict the unpredictable with diabetes :smiley:

As your endo says, its all good and i dont think you should be concerned at all, especially if it “only” goes to about 200 it should not affect performance either, in my experience after 20 years as type 1 i feel performance first start to decrease as i get over 230’s.

So just keep riding it should all be good :smile:

And for reference… my bloodglucose on the picture above dont use the same units as you do, here in Denmark we use mmol/L in stead of mg/dL as you do, how so you can relate, 80 mg/dL = 4.4mmol/L and 200 mg/dL = 11.1 mmol/L.

I hope this can be of any help to help to you.

And also @RyanO i can see from your post that you and i are on the same setup with Dexcom, pump and bloodglucose on watch - i am fairly experienced with riding and avoiding having lows, in fact on usual outdoor rides i rarely carry more than 1-2 gels… so if you feel you got any questions on how you can use your pump more effectively to avoid lows while riding/wants to avoid having to carry food in excess then feel free to ask, im always happy to help if i can be of any use :smile:

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Thank you, @SirNorden. If any questions do come up, I will let you know. I feel like I have a pretty good grasp on things right now. We’re lucky to have this new technology. Things are much easier now than in the recent past!

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What program are you using to overlay your glucose with your workout?

How do you guys like your set up? I personally have the Medtronic closed loop, but thinking about switching over. Thoughts? Recommendations?

@RyanO yes we are idd fortunate to have these options nowadays, and there at coming more and more technology to the market these days… which is just gonna make it even easier for us. I cant imagine going back to the old-fashioned methods, taking a short look at the watch to see the glucose levels are just so much easier than having to stop and do the measurements with a glucometer… has def been a gamechanger for me and my racing performance, riding with normal glucose levels is just so much better!

@ktmccusk i did it using the analyzing tool in garmin connect, i have my bloodglucose written into the .fit files that my Fenix 6 records by the xDrip/Nightscout ConnectIQ app (Spike/Nightscout if you are on Apple devices). From there you can select it in the analyzer and overlay it to your power/heart rate data.
My current setup is a Dexcom G6 and a Medtronic 640G pump, back in the days i used to run both Medtronic pump and Medtronic CGM but i had huge problem with it while riding, basically everytime i started a ride (both inside and outside) the CGM dropped its signal to the pump after 5-10min of riding, and first regained connection half an hour after the workout was done, and it was each and every single day. It had me quite frustrated since the reason i got the CGM was because i am no longer able to feel when i am going hypo, it has to be really really low before i feel it. I have once managed to drop all the way down to 1.4mmol/L (25 mg/dL) during a ride on my local trails…only reason i figured out i was hypo was because i all of a sudden struggled to remember the route, and its a trail i have ridden hundreds of times, thats what caught my attention, otherwise i could not feel anything at all, and the CGM did not alarm me because that one had dropped connection… so after that incident i got a Dexcom CGM in stead and that one is just awesome, very accurate and does not require calibration, cant be more happy with that. Only downside ofc is that it cant communitcate with pump, however i dont see that as a negative since i just use my phone as reciever in stead and run it over xDrip+ and Nightscout, which is what enables me to have all the glucose data on my watch, while at the same time also having the numbers in the cloud so everytime i am out riding, the people around me can follow it aswell, it gives a good sense of security, i can highly recommend that setup (most cgm’s can connect to xDrip/Nightscout btw, not only Dexcom). I hope in very near future that i can get setup with the new Omnipod Dash (or similar type of pump that can be controlled trhough bluetooth), its not yet available here however i hope to get my hands on it soon, since that will enable me to fully close the loop through either OpenAPS or AndroidAPS, which is gonna take even more of the work away from me :smile:

But yea thats my setup currently, can highly recommend it (also with other types of CGM’s and pumps, xDrip/Nightscout as a datafield on the gps or as a watchface for daily activities is just awesome) :+1: :+1: :+1:

I love this thread and seeing so many diathletics! Go go go!

YES! I am less than happy with the Medtronic closed loop, and I am looking into the Omnipod system as my next step. A lot of type one diabetic cyclists feel like it out performs the medtronic system. Regardless I have really enjoyed having the closed loop.

I will have to transition to the xDrip/nightscout. The lack of notifications and alarms with lows is a serious issue for me as well.

Thanks for the responses! Really appreciate them. I think I have been under-sugaring myself (I know that sounds silly) and have been trying to keep my sugars down, even on hard rides, so that I end up not having enough energy and feeling flat. I’m going to try to fuel myself closer to what I used to do, let my sugars climb a bit more than I have, and then see what happens: hopefully they will drop after I end my ride, and my ride will be more productive. I really appreciate the feedback—Jonathan

Hi all,

Thanks @jonathansimmons for the bump, I hadn’t seen the thread. It sounds like you’ve got a good handle on it already. The levels you achieve 1 hour post ride are what I try to aim for. :+1:
I’m a long term cyclist and T1D, so some differences to T2D but also some commonality, so thought I would share some of my experiences in case they are useful.

  • Tech-wise I use Dexcom G6 CGM, xDrip/Nightscout and display my blood glucose levels on my Garmin. As others have said it’s a great set up. I don’t use a pump, but inject instead (slow acting/basal - Levemir, fast acting/bolus - Novorapid),

  • I find on nearly all rides my levels will drop over the course of the ride and level out to between 4.5 and 6.5 mmol/L (81 and 117 in mg/dL), a very similar range to @SirNorden’s top graphic. I very rarely see an increase in levels whilst cycling even when effort levels are higher, although I have a lower level of top end efforts in my riding plan.

  • I nearly always spike 15 ~30 minutes after a session. My assumption is that this down to the increased cortisol levels and residual food still being digested. Insulin sensitivity is also higher during exercise, so once exercise stops sensitivity will fall back again. I think glucose can be absorbed from the blood stream more readily without insulin during exercise, but this is really where one of @chad’s deep dives on nutrient timing and hormone interaction come into play (I think there are some which cover these areas already).

  • If I am on the turbo at home I will inject 15~30 mins before the end of the session to compensate for the spike above and also to cover my recovery drink (40g carbs/10g protein). N.B. I only do this at home so I know I have food to hand if needed.

  • I have found that any residual bolus insulin will dramatically increase the risk of a hypo on the bike, so I do not take any bolus insulin before rides, and prefer to have at least 2 hours gap starting after when I think my bolus insulin will have finished acting (so maybe 4~5 hours in total since last bolus depending upon dose).

  • I tend to keep my basal insulin unchanged (two injections 12 hours apart), however as my fitness increases I find I may adjust the morning dose down to maintain steady background levels.

  • For context my diet off the bike is relatively low carb (no rice, no pasta, no potatoes, no cereals, but lots of veg and meat) to minimise the need for higher bolus doses and reduce the chances of a roller coaster ride with levels.

  • Before and during workouts I will eat carbs, probably 50g (oats, honey) before the ride, only 25~50g per hour during the ride (but looking to increase). This level seems to be covered without taking insulin as above.

Obviously usual caveats apply, i.e. what works for me might not work for anybody else and things are always slightly different day to day
All part of the fun!

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Always happy to help @jonathansimmons actually i think the idea about looking abit into the on bike nutrition could help, as having a steady supply of carbs might actually lower the stress response abit so your body can preserve its energy stores for longer, so you can ride more before feeling flat. As long the glucose levels dont get too high so it impairs performance and still do come down to a good level afterwards it should all be good, as my endo says: going slightly too high (compared to normal levels) while riding is not the end of the world if everything is good the rest of the time, the total time in range is what matters.

@ktmccusk I heard that aswell about the Omnipod, and i must admit i kinda like thinking about beeing able to remote bolus/basal from my phone during a, in stead of having to “dig out” the pump from a pair of very tight bib shorts :sweat_smile: The transition tto xDrip/Nightscout might feel like abit of work to begin with, or well… the xDrip part is quite easy however Nightscout can seem abit harder but i found their guides easy to follow and when its setup properly… it just WORKS, and no missed alarms or notifications, in fact…idk if its just me but i find it almost impossible to miss an alarm i can hear my phone alarming me from almost 100m away :laughing: but that beeing said, if you were to transition into a Dexcom w/ Omnipod system you will stil have the option to have a closed loop, its gonna be a DIY solution tho through OpenAPS or AndroidAPS, but from the “loopers” i talked to who already has a DIY loop setup i only heard good things and it should work out just perfect!

And then ofc thank you to @MBW for sharing your experience, makes me happy to see i aint the only one dealing with the problem of residual bolus insulin on the bike, i need an approximately 2 hour “clear time” just like you do before a ride, also when having it with a meal. I need the bolus to have totally cleared my system overwise i go hypo.
For that very same reason i dont really eat anything during my rides, i found that as long as a workout requires less than 1800 kJ of work i can get away with not fueling and just run on my body’s glucogen stores, however… i must admit, when approaching the 1800kJ range i can feel the stores run low immediatly. The reason i dont eat during those less than 1800kJ rides is because of the temporary basal dosing i use, i found that perfect sweetspot were i can ride were the numbers are just more or less stable… i also think that might be the reason why the stress from those harder VO2 and anaerobic workouts cause my blood glucose to increase. I have however thought about changing that approach abit since bolusing during a ride is a total no go, i am VERY insulin sensitive, i only use about 30 IU total a day (basal + boluses) and thats on a diet with 650-800 grams of carbs daily (except for the one weekly rest day), in fact the lowest possible dose my pump can apply is 0.1 IU and thats enough to bring me from 13mmol/L (234 mg/dL) and down to beeing hypo. However i must admit i have thought about lately changing it to a setup to get the pump to mimic the way your Levemir does, by changing my basal dose slightly up so i will have to eat abit of carbs to keep the same stability, i was unsure about how many carbs would be needed but i will give your layout a try. I have been able to get away without the carbs so far since the mens elite mtb xco races are juuuuust short enough to keep me under the bonk limit however xcm racing has been a total mess for me, either i bonked or ended getting way too high which is just as bad for performance, so def gonna try that strategy out with mimic’ing the levemir and then try your hourly carb dosing, so thank you for sharing that :+1:

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Hi!
I am a T1D and wanted to know from fellow T1Ds as to how many carbs are you guys/gals, consuming during 60-90s min rides?
I usually do early morning workouts on the trainer, so do not have the luxury of eating 2-3 hours before the workouts. I have a gel ( 20g ), right before the session and if more than an hour ride then I have another gel at the 50-60 min mark. I take 30-40% insulin bolus for the carbs I consume pre ride and on the bike and then another bolus of 1.5-2 units, near the end of the session to counter the post ride bump in glucose. I am not taking to the usual recommendation of the 60-90 gm of carbs because I am afraid that the glucose then will either go too high if I do not bolus or too low if I do partial bolus for those.