Ketones next morning after sports

Hi there, I’m T1D for 26 years, pens (Novorapid / aspartum - fast acting + Levemer / detemir - long acting). I’m 34. Generally, I do the sports and exercises on daily basis. Nowadays I skiing, nordic walking, fast walking / running. My problem is that I have ketones early in the morning the day after I had a sport.

Well, a brief diary usually look like this:

13:00 skiing (no keto, no acting insuln, BG is OK)
14:00 stop skiing (no keto, BG is OK)
15:00 BG is OK
15:00 Bolus for lunch, lunch
21:00 Bolus for dinner, dinner
BG is fine and stable all the night, NO keto
04:00 keto is getting higher (++) meanwhile BG is fine and stable
07:00 keto is extremely high (++++) in case of skiing. But it is few lower in case of walking.

In a nutshell, than harder sport I had a day before, then higher keto I have in the morning next day. No sports no keto.

Having ketones I lose weight and that fact worries me a lot. Please advice.

P.S. If I eat several big burgers on the dinner for 300+ carbs then I don’t have ketones in the morning :smiley: But I don’t want to eat burgers every day. So, I suppose I need to correct my evening meals. I eat meat 2 times per day and I don’t want to increase my portions size nevertheless. May be to try something else like sport meal in additional to a regular dinner, etc…?

P.P.S. If I keep my BG is higher 12 mmol/l at the night then no ketones in the morning.

P.P.P.S. Sorry if such question was already somewhere here.

What do you usually eat on sports days?


I’m not the expert in this, nevertheless here’s a suggestion. Ketones are the result of burning fat for energy, which the body does especially when it can’t get enough energy from carbs or stored glycogen. The heavy exercise has consumed the glycogen from your liver, and you need to restore that. How about this. Right after the exercise, eat a large portion of high carbohydrate food with a sufficient insulin bolus. The intention is to restore the glycogen, so your body can use that during the night.


Can you tell me what you are eating before and after your sports activity? How many grams of carbs are you getting?


Generally, all these months I eat the stewed zucchini with boiled chicken breast, white bread for lunch as well as for dinner. Few sweet cookies and chocolate for a dessert, of course :yum: But winter is finally coming now and zucchini is getting out of stock :expressionless: In the winter I eat buckwheat porridge and potatoes sometimes. Every regular meal comes with about 70-100 grams of carbs.

On the breakfast I eat black bread with butter and cheese. Main dish is oatmeal, sometimes with a sliced banana. Also I eat curd sometimes.


Since it is different for walking versus skiing, it really sounds like the harder exercise is making your body try to produce more glucose.

What is your BG? You said it is okay, but what is the number?

Also, how often are you exercising? Is it daily?


I’m trying to keep my BG not less than ~6.5 mmol/l to have some “airbag”.

I go skiing 3-5 times per week afternoon. Nordic walking mixed with running is about 2 times per week. Normal walking with ~5 km/h speed during 1-2 hours - every evening.

P.S. I have ordered a smart cycling trainer and it is on its way to me now. I know keto will get higher much more when I start indoor cycling in additional to the existing activities :roll_eyes:


Don’t be silly, we are a forum, so if you have a question ask away, even if it has already been answered somewhere else. If we remember the thread, we may even be able to point you in the right direction. Glad you are keeping sport in your life.


Are you taking any other medications for diabetes, like metformin?

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I if you are not getting enough energy from the food that you eat then the body will use energy from stored fat generally from the abdomen. If you are burning visceral fat that will show up as ketones. If you have a low or average blood sugar then seeing ketones is not a problem it’s only a problem if your blood sugar is very high. So you may not have a problem at all unless you don’t want to lose weight because ketones indicate that you are burning visceral fat and will lose weight. Sorry if that’s not the situation with you but other type 1 diabetic should know that if the blood sugar was low ketones are not a problem for them.


I agree with what you are saying as far as low ketone levels with normal blood sugar, but the original post stated:

So I think there is an issue that should be resolved. Low ketone levels from burning fat is not an issue. A lot of people choose a diet that does that.

But the higher levels can cause problems.


That’s not entirely true. It’s possible to go into life-threatening DKA with BG below 200. This is called euglycemic diabetic ketoacidosis. Euglycemic diabetic ketoacidosis - PubMed

I’m not saying that the Atkins Diet or a Bernstein Diet is dangerous, but I’m reinforcing Eric’s observation that low ketones may be ok; high ketones are not good.


No, I’m not.


Not sure if this is the same phenomenon, but I ran into something similar a couple years ago.

During mid-2020 I was trying to get back in bike racing shape and doing ~12 hour/7000kj weeks. Because I was a little older and stuck at home, my diet was considerably different than before. Still eating “enough”, just lots less indulging in 3000 calorie fast food after a long workout.

I started to notice a faint sweet smell the hours after a moderate to hard workout. Got some urine strips and started testing regularly, but only occasionally got trace ketones (+, not ++++). Reviewed with my endo and had the appropriate tests but he wasn’t concerned. Eventually training dropped off and it went away.

In your case I’d be very worried about high ketones following exercise for a variety of reasons. I’d start by trying to quantify the energy output during exercise. There are plenty of guidelines and calculators to get a number but it boils down to: is it mild classic skiing for an hour or 3 hours of intense skiing? If its the former then caloric deficit isn’t necessarily to blame, if the latter then EAT!

If you do need more calories then its pretty easy. Stuff like fruit smoothies, recovery drinks, etc, are a fast way to get calories that aren’t as negative as burgers. Basically anything a typical swimmer/cyclist/skier/runner would eat for recovery. Only thing to watch is the bounce from high carb+potentially low bg. Need to be deliberate in what you eat and dose.


Might need extra hydration. Low carb electrolyte drinks?

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