Heart rate during Keto adaptation



I was very concerned about this, because this week my heart rate has been really high. I wear a Fitbit Blaze. Yesterday my heart rate went up to 170 during lunch that lasted 3 minutes. Now that I’m going back to check on my resting heart rate, I can see that it’s been going up by 1 everyday since I started keto. I had already been on low-carb for about a month, and my heart rate had remained in the high 60s.

Since the spike happened during lunch, I blamed it on the salt and the company I was having lunch with. :worried:

Thank you so much for sharing! This is exactly the type of information I was looking for. I’ll be keeping an eye on my heart rate. It brings me hope that once my resting heart rate comes back down it means I’m fat adapted. :smiley:

(Reina ) #22

I wish I had found this site before spending 5 hours in the ER while on an out-of-town trip to Nashville this past weekend. I was 6 days into the Ketogenic Diet.

We were sitting the Federal Courtroom during my son’s High School State Mock Trial Competition when I felt the significant rise in my heart rate. Checking on my Apple Watch, I found it was 88 BPM. Normal is 60-66 while resting. I knew I was not flustered by the Trial, so I shifted in my seat and began slow breathing exercises in an attempt to bring it down. 90 BPM. I tried ignoring it and refocusing on the Trial for about 20 minutes. It continued to remain high and I now had slight throbbing in my right temple. I slipped out of the courtroom to the hallway which seemed cooler, stretched, took deep breaths, and slowly paced. 110 BPM. I decided to visit the 1st floor security station to ask if they had a medical station and could take my blood pressure. 117/72 was very high for me, as I normally run under 104/60. The officer looked at me very seriously and told me to go get checked out.

As my husband and I walked out of the courthouse, I began to experience a stabbing pain in my abdomen that wrapped around my left side and into my back. It stopped me in my tracks, but subsided after about a minute. As we walked slowly to the parking garage, I became very winded, checked my watch again and It showed 126 BPM. I reclined my seat and by the time I arrived at the hospital, just minutes away, my BPM was down to 77.

Long story sh- well, longer…:slight_smile: the ER doc found no evidence of a heart attack, aorta ultra sound was good, all blood work was excellent, but it was determined I was dehydrated, which I found laughable since I drink anywhere from 64 to 100 oz per day. I did feel much better after an IV of fluids - other than the remorse I felt for having missed the remainder of my son’s final round and the award’s ceremony where his team placed 9th in the State.

In retrospect, after evaluating all events of that day, I observed that the episode happened immediately following lunch: a burrito bowl (no tortilla, no rice, no cheese, no sour cream, bu with chicken, charros frijoles, veggies, avocado, and salsa).

I have been meticulously tracking my food intake and heart rate since with no unusual episodes until about an hour ago, immediately following my first meal of the day. I had been seated at the table reading after my meal when I felt the sudden flush in my face and the rise in my heart rate. It went up to 109 BPM. When I reclined in the sofa, much like the reclining in the car on my trip to the hospital, it almost immediately went back down to 77 BPM.

I am curious how many on this site have tracked the rise in heart rate immediately following a meal. Both meals where I experienced this episode were higher than 460 calories. I have had no reactions with smaller meals.

(Reina ) #23

Oh, the ER nurse also found high ketones in my urine, to which he surmised that I was “starving.” I have been taking in around 1400 calories a day and I am not highly active.

(Edith) #24

Allergic reactions can cause hearts to race. Maybe you reacted to a certain food?


My heart rate and blood pressure have gone up since I started keto.

Usually when Im running my HR is at ~150-160 but the last few times ive been to the gym its at 174 (i havent testing my resting HR)

My BP is also up by 10 points

(Greg Borchert) #26

I had a similar experience, where my waking HR that had been low 40’s jumped to low 50’s, and I’d notice a marginally higher than common HR at other times. I think it’s mostly hydration and minerals. At least it was for me. Once I started consciously hydrating and staying on top of electrolytes, my HR returned to where it has historically been.


Ahh, maybe Im not getting enough of my electrolytes and water then! Ill have to up that!

(Greg Borchert) #28

As far as electrolytes are concerned, I have been using a product called “Endure Performance Electrolyte” made by Trace Minerals Research, and also a flavored electrolyte powder called “Ultima Replenisher” made by Ultima Health Products. Both seem affordable. I have used them interchangeably, and they have definitely made a difference.
I don’t want to get into the great supplement debate here, but I also think Vitamin K2 helps, as does low dose aspirin, a little extra Vitamin C and added magnesium and zinc.

(Robert Williams) #29

I know this is old but very relevant. My resting heart rate should be right around 42bpm (I watch it obsessively). I have been Paleo for a year but just starting keto (just got over the keto flu! Fun stuff…) and Dominic’s feedback on actual performance is very relevant to me.

Now in ketosis my resting heart rate is 52, but I’ll report back in a week and with an update. If it is back in the 45-46 range I would consider it back to normal.

(Karen Barkley) #30

Does anyone know what effect Keto would have on someone with Paroxysmal Atrial Tachycardia?

(Robert Williams) #31

If anyone cares, it’s four (4) days later and after balancing my electrolytes (drinking bone broth and pickle juice when I had no bone broth) my resting heart rate is 45bpm. Athletic performance wise I feel great.

(My Healthobs) #32

Hi, I’m glad to read some of these accounts.
This will be my second transition into ketosis and I’m certainly noticing elevated HR.
Rested lying 75 , usually 50
Sitting after 2min 81, usually 52
Standing after 2min 93, usually 62

This is day 2 of adaptation,This is extraordinary for me and I did not notice this the first time I went into ketosis.
My heart rate variability is also low, typically indicating a stress response. Typically rmssd is 30-35, this morning was 7.

I would be surprised if I am low on salt, I gym/sauna regularly and top up regularly to taste.
My recent workout was mild and strength based rather than cardio intensive, even my cardio intensive workouts only produce mild longer term elevations to RHR of 3-7 bpm and decreases of 10 rmssd.

Blood sugar is normal (5.6 on my meter that reads 4.6 on lab reports), ketones are 2.0 which I thought was quite a lot but I heard inflammation can raise ketones, last time I frequently saw 3-6mmol/l

Whilst I do have undiagnosed inflammation issues (Sjogrens/lupus)? my fitness is ok and I guess this heart rate will fall.
Feel fine otherwise, in fact I feel less inflamed than normal

(Rob) #33

Not my area but if you topped up due to gym/sauna use, you will probably need much more on keto and “to taste” probably won’t cut it. Keto is very diuretic and many ketonians take in 5-7g of sodium (10g+ of salt) without exercise. I don’t hit the gym at all but do well on 6g a day of sodium.

It’s worth looking at your actual intake if you log. You may be sodium sensitive but odds are you aren’t.

(My Healthobs) #34

Thanks, yeah ok, last time I was in ketosis I did 1teaspoon/day (2300mg na) in addition to an approx 1600mg through diet . I have a few of the salt sensitive genes so reading between James DiNicoliantonio and the mainstream recommendations it’s hard to know what to do, BP is typically 115-145 / 65-85 but I am seeing a correlation between salt and BP.
Anyway I’ll try more and see what happens, thx for feedback

(Omar Maarouf) #35

exact same effect , i was scared from the HRV it was so low for a week lower than even when am sick , its still low now after 11 days , but getting better , heart rate increased be 8 points resting , but started decreasing 2 days ago


I’m not actually doing Keto since I think I would have to get used to the recipes first, but I upped my fat, and decreased my carbohydrates.
Within a week my pulse rate was over 100. and still is I had added a small amount of MCT oil to my coffee. I searched and found online that it has caused fast heart bear. I stopped that two days ago but am still following high fat low carbs. Still high heart rate.
I have to wonder if there is a correlation even though i’m not strictly Keto. (Before I ate everything non or low fat so this increase in fats is a big difference for me.)

(Sonny) #37

Just adding my experience.

  1. Was in Ketosis last month, noticed elevated heart rate, got scared and got out of Keto - heart rate went back to normal.
  2. Tried to go back into Keto and started consuming full fat coconut milk and noticed heart rate going up. Assumed that I have Coconut allergy, stopped it, stopped trying for Keto and the heart rate went back down.
  3. Tried MCT oil to see if it would impact heart rate. MCT put me in Keto and heart rate went up. Figured that MCT oil is from Coconuts so stopped it. Fell out of Keto. But this time I continued Low carb, High Fat. Some mornings I wake up in slight Ketosis. Heart rate is still elevated, rises after a fatty meal. Supplementing with Magnesium, Himalayan Salt and Potassium and Bone broth. Sometimes I see a difference, other times I don’t.

Absolutely frustrating.


I know this thread is super old, but thought I would add in my experience just in case someone in the future finds it useful!

I’m on my 4th day of ketosis, but it was last night when I noticed my heart rate being abnormally high while going to bed. Typically, my resting heart rate is around mid-high 60’s. I measured it last night and it was high 70’s. It was definitely a cause of concern hence why I’m here.

According to what I’ve read, it’ll go back to normal after my body adjusts to this diet. I’ll try to update in a couple weeks on whether or not my heart rate goes back to normal.

(Cassandra Benoit) #39

I just wanted to also say, that out of nowhere my heart rate when as high as 119 normally 70’s 80’s. I was panicking. I am on my 2nd week of keto. I am also experiencing the constant sweaty small, so I guess this is a side effect as well.
Anyway, it is night te and it is slowly going back down. Not where it used to be but below 100. Also, this morning I woke up 3.4 pounds lighter from yesterday. A total of 13.8 pounds down in l.5 weeks. So, I will monitor it. I also have HBP and my readings have been all over the place today as well.
Will update sporadically.

Good luck all.

(Sonny) #40

Hey everyone, after almost 2 months of dealing with high heart rate, I think I have finally figured out my issue. Here is my process to troubleshoot this issue:

  1. At first I thought it was Keto in general and stopped it for a week to make sure it wasn’t a permanent condition.
  2. HR went back so started Keto again. Thought the issue may be the full fat Coconut Milk so stopped it but the issue continued.
  3. Stopped taking Synthroid to confirm it wasn’t overdose, but issue continued.
  4. Thought it was low elecrolytes so starting taking lots of Sodium and some Magnesium and Potassium but the issue continued.
  5. Noticed that HR went up after eating Almond butter so confirmed it using Apple Watch. So no more Almond butter.
  6. Noticed HR went up after eating Macadamia nuts so eliminated them.
  7. Noticed HR went up after eating Pecans so eliminated them.

At this point, I have lost an unacceptable amount of weight and the only fats that are not causing a reaction are Olive oil, Avocado and possibly Ghee (need to test).

I just started drinking spoonfuls of Olive oil to increase my calorie intake but feel weird about it. Would love to hear some feedback.