Going back to the gym

Hello all! My son is 14 and was diagnosed about two months ago. We used to go to the gym together 2-3 times a week, but have not gone since before his diagnosis. As I’m sure it is with most people, he was in the ICU and in the hospital in general for about five days. So I really wanted to give him time to rest his body, and get his BG under control. He really wants to get back to going, so we are going to take it slow. Start with some treadmill waking and see how it goes. So my questions would be for anyone who works out or does any sort of athletics. I’ve done research online about this, but would definitely feel better asking this community.

I understand that everyone’s body is different, and his body will not react exactly like somebody else’s. But I guess what I am trying to do is just be prepared in general. We’ll have fast acting glucose, plenty of water, and all needed supplies with us.

I’ve read that he should eat some carbs beforehand, but recommendations on approximately how much? Like are we talking some fruit snacks, or something more substantial like a sandwich? How quickly does that type of exercise generally make your numbers go down when it come to the aerobic stuff like the treadmill? I’ve read that things like weight training (or using the machines) can make your numbers go up? (We won’t be getting back into that right now) And also that sometimes (all the time?) your numbers may not go up for hours or even a whole day later??

Any advice on how to prepare his blood sugar prior to going would be greatly appreciated, in addition to any general first-hand knowledge of what I can expect to see his numbers doing while we are there and afterwards.

Thank you all so much!

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hi @SarahSMS welcome to the Type One Nation forum. YOu have to get used to using your blood sugar meter (or cgm) as a tool. Is he 180 before the gym? yes… then no need to carb before. did he just bolus for lunch? yes… then he’s very likely going to drop while working out because of the insulin from lunch time.

please consider getting a plan from the CDE or doctor. Please also consider reading “Think Like a Pancreas” for starters.

many people find that lifting weights (anaerobic exercise) can raise blood sugar. many people find that aerobic exercise like treadmill, swimming, running bicycling, lowers blood sugar. all exercise makes my blood sugar drop if I don’t prepare and especially if I am active within 4 hours of a meal bolus.

carbohydrates makes your blood sugar go up fast, insulin makes your blood sugar come down slow. So you are either reducing insulin, or adding carbs, or both.

if your son is still honeymooning… he might not need any insulin for a meal before a workout, he may need much less. the way you tell is by frequently checking blood sugar and makin any adjustments you can. If he takes a long acting insulin shot then get a doctor recommendation (he may need to anticipate a workout and reduce his shot)

I use a pump and it has been decades since I was honeymooning. All I really need to do is decrease basal in my pump and then I can work out and I don’t’ need to add a ton of sugar. This allows me to control or lose weight. If I wanted to gain weight… I would use more insulin and more carbs. the increase in calories from the carbs and insulin will tend to help you gain weight. A plan (strength, stamina, muscle gain) and then if you are adding calories or cutting insulin - is the way to start a good program. Then I strongly recommend testing every 15-20 minutes with vigorous exercise and making sure he’s not going low. if he has a cgm, that’s easier by far, but please be aware a CGM may not be fast enough to catch a low during exercise

the basic increment for adding carbs is about 15 grams. or the equivalent of a slice of bread, 3 glucose tabs, 1/2 of a 30 gram carb gatorade, a small apple, etc. The carb content is listed on most packaged food or can be looked up online. Please be aware that carbs have a glycemic index, we refer to them as fast carbs or slow carbs here. to raise a low - use fast carbs, glucose, sucrose, to a lesser extent fructose. to stabilize after a workout… use slower carbs (or make a carb slow by adding good fats or protein).

exercise is great, don’t let it intimidate you or your son. you can get an idea of how sensitive he is to exercise by taking a brisk walk for 15 minutes, testing before and after and then 1/2 hour after.

hope this helps a little.


Does your son use a pump, or injections? If he is on a pump he can switch to Activity mode - how far in advance and for how long are things you would need to determine with trial and error, as are snacks.
That said, your nutritionist can recommend snacks with “staying power.”
Keep very detailed logs if you’re not already doing so - it will help you determine patterns to discuss with your doctor until you’re comfortable making adjustments on your own.
Here’s a link to an article about athletes with Type1:


Thanks Joe. I watch his Dexcom app for patterns with his food and keep my own logs for that. He’s on MDI right now. He can’t be considered for a pump for at least 6 months after Dx. I have the book and just started it the other day, so hoping to get more good info from that.
I’m so Type A and I want so badly for this to be a black and white situation that I can 100% plan for and be in total control of :sweat_smile: But I know that’s not reality.
I didn’t take into consideration his long acting injection and how exercise may affect that dose. We have an appt with his endo on Monday, so I’ll definitely talk to him about all of this.
I really appreciate your input!

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Thank you for the article! I’ll read that now. He’s on MDI for the first 6 months after Dx. Then we’ll consider a pump for him.

@SarahSMS Welcome Sarah, to the JDRF Community forum! What you posted tells me that your research has provided you with some accurate information, and @Joe has provided you with much of what I can offer.

You are correct in saying that “everyone is different” so what I offer may not apply ti your son. For me, gym workout has two points I can offer; I would eat a “normal” lunch and my meal bolus I:Cr [Insulin to Carbohydrate ratio] would provide me a little less bolus than on non-gym days. I’d then rider my bike the three miles to the gym for my warm-up followed by upper body “relaxed strengthening” - I’m an octogenarian. After ninety miles I’d ride an eight mile route back home; on rainy days I’d spend time on a treadmill or stationary bike. Yeah, a long boring intro.
Usually, I didn’t need to do anything to elevate my BG except to eat [for my safety] a few packaged PB sandwich crackers before my bike ride home; during my workout and biking my water jar had a scoop of powered Gatorade [with sugar] to maintain my BGL [Body Glucose Level]. Over the years I’ve learned the amount of Gatorade my body requires per hour/mile for activities.

This method has worked well for me, BUT occasionally, during gym I’d need to drink a juice box and on other days a couple of hours after supper my BGL would suddenly drop sharply and necessitate a good snack. Bottom line, diabetes is unpredictable so always be prepared and have handy carbs.


Thank you Dennis. I appreciate hearing your routine and how you handle things. It sounds like you have it down to as much of a science as diabetes will allow, in all its uncertainty.

I’m really looking forward to giving my son back some normality in his life by getting us back into a routine. The idea of exercise when you’re newly diagnosed is intimidating, since I know his body is still adjusting. But reading these replies has really made me feel a lot better about it.

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Apparently some people start on a pump right after diagnosis but I believe it’s important to know how to manage on injections as well, so it’s good he’s starting off that way.
The pump - particularly a “smart pump” combined with a CGM - is generally considered the best way to manage diabetes - but some people do just as well or even better on injections and may feel pressured to get a pump even if they aren’t excited or motivated to do so. Of course, your son may well really want one when the time comes - but if not he shouldn’t feel pressured to get one if injections are working well and he’s okay with them. Just a thought to keep in the back of your mind - and his. If he does switch to a pump be sure to review his “injection strategy” periodically - those needs may change and he should know what to use if he takes a pump break (which reminds me - I need to do that at my next visit!).
Sorry I’m getting a little off topic - I tend to do that now and then. Consider that something else to tuck in the back of your mind for now :blush:.

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Thanks Dorie! The way it’s set up here at the hospital where he was diagnosed, and where his support team is located, is that you have to do MDI’s for a minimum of six months before being eligible for a pump. And then there are courses that need to be taken at that point. But I am glad that it’s required this way because I see the importance of understanding how to do calculations and shots. We all know technology is not infallible! My goal is to get my son to know how to give himself his injections by the time he’s ready to switch to a pump. Since he is 14, he won’t have me here to give him shots for very many more years when they are needed. Understandably, he wants nothing to do with injecting himself at this point :sweat_smile: but he understands that we need to work towards that.

As much as I hate the fact that my son is going through this (and I do hate it with every bone in my body), I’m very, very grateful that it’s happening at a time with such advancements in management.


Here’s a link to a topic on fear of giving injections. Hopefully you’ll find some encouragement and tips from people who are managing it. My mom said she practiced on an orange (I guess she used water) while learning to do mine - maybe that’s a place to start.

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Hey, I’m Taylor and I’m a 16 year old boy. I’ve been diabetic for almost two years now. I am very physically active. So active that the day I came out of the hospital, I played in my schools basketball game. In addition to basketball, I also play football and water polo.

My advice is every time before your son works out, eat 15-20 grams of carbs AND 15-20 grams of protein. The carbs will keep him stable for a little bit, but the protein will boost his blood sugar over the long run. I usually eat a granola bar, one of the protein Nature Valley chewy bars. Those work great. It usually doesn’t spike me at all.

When I lift weights, my blood sugar can drop. It’s about a 50/50 chance that it either stays steady or drops. Usually those drops aren’t severe, and most of the time I never drop below 100. I usually need to eat something within 30 minutes of ending my workout (which as a teenaged boy, isn’t very hard for me) otherwise my blood sugar will drop. Cardio usually doesn’t affect me as much. My blood sugar usually doesn’t move at all, during or after the work out.

If I get low while I’m lifting, my first choice is Gatorade. Liquids usually absorb faster than solids, so any kind of juice works for me. And simple sugars over complex. Simple sugars absorb faster and shoot blood sugar up higher than complex. I’ve found that about half of a small Gatorade bottle is enough to get me working again. Once I see my numbers start to perk up, I can start training again.

If he has the Omnipod 5 (which connects to Dexcom) then the activity feature is really nice, but only if you can keep the PDM near him. So when I’m lifting, I use the activity feature, but during my sports I just completely cancel basal. Now I’m not technically supposed to completely cancel basal for over 2 hours, but I do it anyways because otherwise I get low.

Personally, I don’t see any reason to ease into working out again. Like I said earlier, I went straight to a basketball game. Everyone is different, but I think it should be fine.

Last of all, I don’t work out if I’m below 100, especially for sports. If this happens, usually I just drink a lot of Gatorade. This’ll shoot me up, but because it’s not a complex sugar it doesn’t hold for very long. Usually it all works out though.

Hope this helps! Let us know if you have anymore questions.


Thanks Taylor! All of that was extremely helpful. I guess you’re right, we don’t actually need to tiptoe back into exercising. I guess that’s just the mom in me wanting to make sure that he’s not overdoing it :sweat_smile: I’m going to pick him up some of the protein granola bars, thanks for the tip!

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When it comes to carrying things in your pocket or purse to help with lows, there are a lot of options. There are glucose tablets, lifesavers or similar candy - carbs vary so check them out to detrimental how much or many to use. My favorite is Clif Bloks, which I found at a sporting goods store. I don’t care for the consistency of glucose tabs but do like the Cliffs - they’re a gel but not rubbery like gummies. They come in different flavors but some have caffeine if that’s a concern.
I do prefer liquids to raise my numbers quickly if necessary, but I chose these for something easy to carry around.

I personally work out at least three times a week, what I do personally is I usually eat according to my ratio, (for example, every 12 carbs is one unit for me, I eat around 15 or more but not much more) some people eat fast acting after, or even a honey bun or something, a lot of people would bring something that’s a complex carb (look it up on the glycemic index if you’re not sure, if you want to eat beforehand I HIGHLY suggest researching into the glycemic index) I work out for around 15-20 minutes, walking WILL, in most if not all people, as for any movement lower blood sugar, if you can get him a CGM to make sure to that’d be perfect for exercise especially, DO NOT let your child overwork them self because that can become dangerous, check glucose often if you don’t have a cgm on them. Good luck and happy hunting.


Hi! I wanted to jump in here with the convo. I have a very active 12 yo t1d son, and T1D myself for 36 yrs. Exercise effects him differently than me. For him, more than approx 1u of insulin on board, and he will likely drop hard. We try to dose and eat 2hrs prior. Im less sensitive. I say that because, there is no black and white…which can be maddening at times. You will find a lot of patterns that help you predict what will happen…but it just doesnt always respond the same. Which means, do what you expect to work, but be ready for other outcomes. Also know that Dexcom is 10-15 min behind, so when active, we will either treat before truly low or finger stick to know for sure.
There is a great Facebook group called Proud Parents of athletes with Type 1. There are lots of conversations with tips and ideas for sports.
We both use the Tandem (Tslim/Dexcom) and that helps prevent lows with activity.
He will find a new rhythm and routine. Best wishes to you both!


As you can see people have a lot of different solutions to this. Take a guess on one that seems like it will work and try it but watch the readings on the cgm. If that doesn’t work try something else. Ultimately he will find what works for him. I was diagnosed at 11 back in 1976. Initially I refused to give myself injections and my parents did that for me. When I was about 14 or 15 i went to camp Nejeda a diabetic sleep away camp for a week. They told my parents that they would help if needed, but as soon as I saw the other kids injecting i just started doing it and have ever since. Good luck to both you and your son.

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True and recent story on this note: I injured my leg a few weeks back and started physical therapy a couple of weeks ago. My first appointments were in the mornings - which have always been my best time for working out: in my case I ate a normal breakfast, took my usual insulin, and set Activity mode in my pump for a couple of hours, starting about an hour before my session. Things were perfect.
This week I switched to afternoons, knowing I might have to make some adjustments. I ate lunch at 11:00 - my usual time, and bolused as usual for the packaged meal I took. I lost track of time and only turned on activity about 30 minutes prior, and as luck would have it when I parked my car I was only about 120. Ordinarily that would be fine, but I tend to drop with exercise and the one block walk across the parking lot didn’t help, so by the time I checked in my next cgm reading was lower, and I had the dreaded :arrow_down: on my CGM. I chugged some juice and told my therapist I needed to go downstairs and grab a snack - but it was going to take some time for the numbers to stabilize so she came down to check on me and ultimately excused me from the session.
This is my 60th year on insulin and you always need to stay in tune with your body and learn its patterns, its needs. I could have tried adjusting my lunch bolus given that I would be exercising later - but I didn’t. And I should have turned in Activity sooner but I forgot. When things don’t work out, take them as learnings and adjust as necessary. I went again yesterday and did start activity an hour in advance. Still need to fine tune my lunch dose - I had to eat a snack before going in - but got through Thursday’s session with no problems.

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