Long distance cycling (need insulin?)

I’m re-starting going for long bike rides 1-4 hours. Currently I take Tresiba basal and Fiasp bolus.

I’m wondering is there any reason for me to bring my insulin with me? In the past I’ve brought gatoraid, snacks etc… because I need them to keep my blood sugar up.

Since I’m on Tresiba I can’t really adjust my basal before a ride but I think the plus side is I shouldn’t need to bring any insulin because my basal will likely prevent me going/staying high on a long ride.

I’d prefer not to bring insulin because of all the vibration and possible heat exposure it would endure on the ride.

I’m curious what others do, thank you

I think you are good without it since you are exercising! Take your snacks

1 Like

Bring some preloaded syringes. (Get the syringes with 1/2 unit markings.)

If you put a unit or less, you can put the plunger cap back on the end. It will still fit without pushing any insulin out, and it will prevent the insulin from being accidentally expelled.


There is never a downside to having insulin with you.
Oh no, I didn’t use it!

So what? You wasted a couple syringes and a few units of insulin.

Also if you get delayed, if you get a flat or anything like that, you should have insulin with you. A 30 minute ride is one thing, but a 4 hour ride is a different story.


I am never separated from my insulin, because it has been keeping me alive for most of my life. I would take it along while on a long bike ride just in case of being in an accident. Sure, it will probably never happen, but it really shouldn’t be too difficult to take a little along just in case.


I don’t do really long rides anymore, but I used to. I used to the Great Ohio Bicycle Adventure (GOBA) every year, which is 50-100 miles a day, and lots of similar training rides.

I never once went without insulin, and never, ever, ever would.

True, you might not need insulin on a perfect ride, but then again, you might. If you exercise in such a way that releases adrenal hormones, it can actually cause your BG to spike. The bigger concern is that not all rides are perfect, though. You just can’t plan for everything. What if you over-correct a low? What if you consume enough ride fuel carbs to need a bolus? What if you get in an accident or have a breakdown which leaves you away from home for hours (days??) longer than you anticipated. When insulin is your lifeblood, is goes with you everywhere. Period.

Insulin is not nearly as fragile as you think it is. Vibration is no concern. Sure, it will introduce some air bubbles, that will fall out of suspension all on their own, but it will not degrade the insulin. Heat is also surprisingly not an issue. The guidelines the manufacturers give are for perfect long-term storage and FDA mandated for warehouses, pharmacies, and shipping standards… So the patients at the end of the line all get similar vials of insulin. But for short-term usage, that all goes out the window. It’s actually really difficult to denature insulin. Even “baked” insulin is only marginally less effective than pristinely stored insulin, and insurmountably better than NO insulin at all when you need it.

This is a pretty old thread, but it was the one that really launched the “don’t fear the heat” mind shift in the community:


I use insulin pens so I was concerned the hours of vibration and being outside in 80-95 degree temperatures might be an issue.

In the past I’ve never needed insulin because I’m always needing to consume carbs. I assume its my basal insulin causing me to go low when on a long ride. Since I take Treisba I can’t one afternoon decide to have a half basal, that decision would need to be made a couple days ahead of time.

If I do take my insulin I can’t imagine taking any until I see a number above 250. When I’m exercising insulin can be 4-5x more potent then normal.

For pens you can use a Frio to keep them cool. Cheap and reliable.

I also recommend carrying some insulin “just in case”. I play a lot of ice hockey and always bring some insulin in my gear bag. That’s just in case my pod gets knocked off etc. I use a spare hard glasses case to hold a vial with maybe 20 units in it and a couple syringes. Have never had to use it but it provides peace of mind.

1 Like

I think this questions might be answered differently depending on if you use a pump or basal shot.

It seems like a pump failure would result in DKA more rapidly because the insulin in your body would be gone fairly quickly without the pump. I don’t think the same is true for a long acting basal shot.

At minimum if I bring my shot I can stop and get a meal without worry.


Its worth your doctor prescribing a vial of insulin for the riding season. I always take insulin on a long ride, simply because I might have to stop for an extended period. If I do I have it, if not i waste it and go on.

A vial and 40 syringes will likely do it for an entire season. Ask your doctor to prescribe an emergency vial.

I would fill a syringe with 25 units. And take it with you.
I try to never be without insulin. I have a pump so I usually have a reservoir to draw from if I needed it.

When I was on mdi, I always had insulin with me and felt anxious if I didn’t.

If you had some afrezza you could keep it in your car or on your bike without worrying about heat or anything.

I used to keep exubera in my desk at work for that reason.
However exubera was really terrible in general

As long as everything goes to plan you would be ok. The issue is you need to plan for the unexpected.

I never go without extra insulin or carbs. I don’t want to be a news story.

This is definitely a personal decision. And there is no right or wrong just what works for you.
I use to never leave the house without my kit that had everything in it. Just never know.
But even with going on walks for hours, I don’t take insulin with me. Carbs, of course! But my thinking is, I have my phone and if something were to happen, I could just call someone to help me, bring me some insulin, pump supplies etc. So if your bike ride keeps you in phone cell range, maybe not necessary. But if having it with you reduce your worry, ring some. Have fun getting back out there for those long rides!

1 Like

Agree on personal preference and previous experience. I’m not a pumper (MDI with Toujeo as basal and Humalog), go on rides of 1-1.5 hrs and never take insulin with me. Never overcorrected with that level of activity sending insulin sensitivity into overdrive (only 10-25g carb corrections) and have not considered that a major risk. Just bring enough snacks and keep eating carbs periodically to avoid lows. I hate feeding the insulin like that but keeping an eye on Dexcom through my Apple Watch is a fantastic tool - also gives me an excuse to take some periodic breaks. I suppose there’s some risk. I always bring my phone in case I’m unable to repair a flat tire or have a severe low.

I went for a 3 hour ride this weekend, I did bring the insulin but never needed it. I never went above 120. I did have to eat a lot of snacks to keep my blood sugar up.

I think its a lot different when you’re on MDI vs pump. Its never bad to have insulin with you but when on a long acting basal and exercising more then normal its likely you’ll be fighting going low.

1 Like

I am on MDI and I always have insulin with me even if I don’t plan on using it. I have it in case I might not make it home as planned due to some unforeseen circumstances.

1 Like

Since you said you use pens, another thing you can do is whenever a pen gets down to being almost empty, like 5 units or so, set it aside for cycling.

You can put one of them in your cycling pack, and you can rotate them out every few weeks. That way you don’t need to worry about them going bad, and you don’t mess up your regular pen.


@ChrisP I’ve been reading through this thread since the beginning, I am a T2DM using a pump cyclists. I can’t find data to confirm it, but there have been times after a couple of hours in the saddle that my energy level was decreasing, even though I wasn’t hypo.

I lent my copy of Sheri Colberg’s Athlete’s Guide to Diabetes, but it was from that book, iirc, that low insulin during long exercise can lead to fatigue.

There have been a few times that I have given myself a bolus slightly higher than the carbs I would eat. This seemed to improve my stamina while not jacking my BG into the stratosphere.

I would carry a syringe with some rapid insulin in my bag. Later I was carrying 2 pens in a case in my back jersey pocket. Now that I am on a pump, after reading this thread, I think I will carry a syringe of Rapid in my bag, in case of a pump failure.

You can’t absolutely depend upon electronic devices when your life is on the line.

Keep rolling along, Chris. Show a clean set of wheels to those behind you and keep the rubber side down.


I plan to bring insulin on any long rides even though I don’t expect to need it. I do need a lot of carbs though.

Last right
22 carb gatoraid
10 carb rasins
10 carb rasins
9 carb protein bar
20 carb peanut butter crackers
20 (5 tablets) carbs glucose tables

My sugar during the ride was 90-120 but I had to continually consume carbs. Next time I actually plan to bring more carbs, I finished the ride with only 6 glucose tablets in reserve.

1 Like

Unless I missed it upthread, there’s one additional consideration I would introduce as a distance cyclist myself. It’s pretty common knowledge that intense, non-aerobic exercise can trigger an adrenal response that raises BG. Cycling, being of the steady aerobic variety, doesn’t usually have that effect. But on rare occasions I have ended a ride considerably higher than I started out. In particular, riding in cold weather, near or below freezing, seems to have that effect. Like my adrenal system concludes I’m in an emergency situation—chased by a polar bear maybe?—not just getting my daily workout, and goes to work preparing me for a life-or-death encounter. I’ve had rides where I started out at 120 and ended up at 170. Sometimes riding in higher temps can do the same. It’s rare, but it’s definitely a thing.

I am using a pump rather than MDI, so the question of taking insulin along doesn’t apply for me. But I would just note that the BG lowering effect is not 100% reliable. It can go the other way!


When I got the Dexcom, I have seen this in action on the bike. If I do some hard intervals or hill climbs there will be a rise in BG. It is the stress that does it, same can happen in weight lifting. If I were stronger, both on the bike and when doing resistance the effect would be higher.

1 Like