Abnormal run training heart rates


Hi, I am a newby here. I have a problem which I hope I can find some answers to here, I have searched and read what I could and cannot really seem to find the information I need to know. I am becoming quite desperate and confused now and hopefully I can get some answers here.
I am a runner and have been a runner for 30 years now, with a few years off here and there due to injury or motivation issues. In the 80’s I ran quite well clocking 14:25 (5000m), 29:52 (10000m) and 2:25 (Marathon). After a long sporting break of about 8 years or so I started running again in September 2015 and very slowly built up my condition so that I could train solidly and race now and then.
In October 2017 I began a Keto diet and am now into my 5th month of running keto, which has had its positive and negative effects. Especially the anti-inflammation effects have been a godsend. I no longer have painful ankles and hips like I did on my high carb diet, I wish I had known about that earlier. I dropped 6 kilos without even concentrating on dieting at all. I had no problems with the adaption phase, maybe a little tired the first week or two when running but nothing else. I measure my blood ketones every day and have been in moderate ketosis (1.5) since I started.
My problem however, is with my running and my heart rate. I am a data junkie and have all my data from all my runs of the last 30 years. I am always monitoring my body and training to look for anomalies or just to optimize my training as best I can. Here are my issues I have which totally confuse me and hope this forum can shine some light on them for me:

  1. Every morning I measure my blood pressure. Since I went Keto my blood pressure has dropped significantly from 120/80 every morning to 105-110/60-65. That is a large drop. Why is that?
  2. My resting pulse has gone up from an average of 42 beats in the morning to 50-54 beats.
  3. My training HR is constantly 20+ beats higher than before going Keto. An easy run for me last year was about 130 bpm. Now it is never under 150 bpm, and even a slight effort uphill or faster pace I shoot up over 160. I do not understand this because I have not changed my training at all. I thought it was only because I was new at keto and it would gradually get better, but it didn’t. After 4 months it hasn’t changed at all. Before Keto I could train comfortably at a 4:30 - 5:00 minute per kilometer pace, now I am lucky if I run under 6 minutes per kilometer. And I have the feeling it is getting worse rather than better. I have been running a constant 80-100km per week without any noticeable drop in my training pulse. Past experience has shown that a 10 week block of aerobic run training would decrease my training pulse at the same pace by a good 10 beats. It hasn’t gone down at all, in fact it has gone up. My HR is also very volatile I have noticed. A slight incline and it shoots up 10 to 15 beats immediately.
  4. Speed work: Last year before keto, as an example, I did a session of 10 x 400m in 1:20 (average pulse was 155-160). Last week, I wanted to do 10 x 400m, I was dying already by 5 and had to stop after 7 as I was totally exhausted. I was averaging 1:34!!! And my pulse was averaging 170+. I had totally no energy at all, and the more I did the less energy I had, my legs just got zapped completely. In fact any kind of fast running, fartlek etc, is pushing my HR up into the clouds, and my legs are like jelly.
    Anyway, after last week’s speed work I just wanted to stop my keto diet, go back to my old high carb days so I can run like I did last year. I was very depressed, and I still am. But before I take this step I thought I would write about my problem here, maybe someone can explain to me that it is something simple and I should not worry, but I fear it will not be so. Am I not suited to Keto run training? Why is my HR up so high, my blood pressure so low? Why is running so difficult now? I am quite desperate about this, I had some pretty high Age Group running goals for the future, and what I thought would help me by changing my diet, is not helping me at all, in fact it is doing quite the opposite. Running was always my greatest passion. But now I am starting to hate it! I would greatly appreciate it if someone could help me on this.


Wow, those are some serious speedy times that you did in the 80’s - very impressive ! I am still newish to Keto but my experience is similar to yours :
Positives : Weight loss, anti-inflammation effect, faster recovery ,improved blood pressure from 138/90 to 125/85 , deeper sleep.
Negatives : Running performance loss in 5k, big struggle going uphill compared to pre-keto , cold hands and legs all the time !

I had a banana and a date before my 5k this Sat’day and improved my 5k time by 45secs.


I am not sure my blood pressure has improved. It was 120/80 and dropped to a little over 100 to 60, I am sure that is not good. But your blood pressure has really improved.

(Tom Seest) #4

I’m not a runner, so I’m not sure how much I can help. But, I have a few suggestions:

  1. Get your intracellular levels of electrolytes checked out. Usually, you’ll have to order tests like Magnesium RBC, Potassium RBC, etc. Your doctor should be able to help. If these are off, it would explain the higher heart rate and reduced level of productivity.
  2. Another easy check is to purchase a pulse oximeter and make sure that your circulation is good and that your oxygen levels are good.
  3. I would also look into Peter Defty’s VESPA product and program before returning to High Carbs. They do tailored coaching for athletes and run the blood lab work, and can find any deficiencies that may exist. It’ll cost a little bit of money, but it could bring you piece of mind. You can find more about this at: http://www.vespapower.com/

I hope this helps.


Thank you Tom. My bloodwork is good, I did have it checked recently. I am taking potassium and magnesium as a supplement twice daily and also plenty of salt and water. I have ordered a pulse oximeter to check that out, thanks for the tip there. I will update once I have it and have tested. Cheers!

I was wondering if anyone else, especially runners, or any endurance athletes have experienced this?


I started keto three weeks ago and have found I can not train at all like pre keto. I have been running seriously for about six years and I use the maffetone heart rate training method. I do most of my running at a heart rate of 130-135 bpm. I have found my heart rate jumping to 150bpm even at very moderate efforts and much slower than I normally run, and have found I have to slow to a walk to get my heart rate down to my 130-135bpm training range. I would also like some help for this.

I did lose about 4kg quite quickly, feel much better and am sleeping deeper and longer than I ever have.


Steven that is very similar to me. I think it is definitely keto related. I found an interesting statement today by Dr. Andrew Coggan on this high HR issue:


One of the negative consequences of inadequate carbohydrate intake is a reduction in plasma volume, and hence reduced cardiac filling pressure and hence reduced stroke volume. Your body attempts to compensate by increasing heart rate, but cardiac output still tends to be reduced, requiring greater shunting of blood away from your liver/kidneys/intestines toward exercising muscle. Skin blood flow also tends to be diminished, thus impairing exercise capacity in the heat.


I think that explains exactly what is going on. Now all I need to know is how to “fix” it.

(Jack Brien) #8

Have you tried bumping up your Na a bit more? My BP gets quite low, without me eating quite a bit of salt. I sweat buckets when working out. The low BP and increased hr could well be connected as an increased heart rate is a compensatory mechanism for low blood pressure and insufficient blood volume, though I normally see it when patients are bleeding out, which hopefully you’re not

(Tessy M.) #9

Inflammation, or a reduction of inflammation in your case is quite possibly the reason your BP went down.
Inflammation is considered the underlying issue for CV diseases.
The rest I can’t even explain, but I’m wondering if the pulse might be tied to this in some way.


Jack I almost spat my coffee out reading that last sentence, I got a laughing fit :slight_smile: I hope you don’t see too many patients bleeding out. Thank you for the infos, it sounds rather logical if you think about it. I will try experimenting with my salt intake.


I didn’t know that about the BP being affected by inflammation, thank you for that information, all these little bits of information give me a clearer and larger picture now. And as I said to Jack when I replied to his post, it all seems quite logical looking at it from these different perspectives.


I am not a runner but do a lot of cycling. Myself along with others on this forum have experienced lower blood pressure after a workout. Thoughts have been possible dehydration caused by lower blood volume and or blood vessels dilating causing lower pressure.

I initially experienced the higher heart rate. I now drink a cup of bouillion before going out for a ride. This seems to help.

I have also experienced a lack of max power. Have been keto and fat adapted for about a year. what seems to help is taking in a little carbohydrate if I am going for a hilly ride. Seems to help a little and does not knock me out of ketosis.

For some good information about all of the above listen to Brad Kearns Primal Endurance Podcast #90 with Peter Defty. Some of the information might be controversial but answers a lot of your questions.

The one point Peter Defty brings up that scares me a little is that if your body is in Ketosis to long it will not know how to burn carbs when needed.


Thanks for the insight. How to know if I am low in salt and is there good way to boost it? Do you know why avoiding carbs leads to lower salt since meat, eggs etc. are sort of salty.

(Paz Efrat) #14

I am glad I found this post. I just started Keto 3 weeks ago and have recently began to experience the similar symptoms with higher heart rate and difficulty keeping up when working out. Here is what I have observed so far:

  • First few days of Keto: Foggy; craving food despite eating regularly throughout the day; no “Keto Flu” per se, just fog and cravings. Ketones level climbed a little each day to about 0.8 and then stopped climbing. Also lost about 5 lbs the first few days.
  • by end of week one: Fog mostly gone; felt more or less back to normal. Able to go for moderate jogs without any problem, but took it easy so as to not push myself too much too soon. Weight staid stable.
  • Week two: overall felt normal, as before the Keto diet started. Began going back to the gym for HIIT workout. Drank supplemental ketones prior to the workout and did well overall (this was my first time at the gym in a few weeks, so expected to have a bit of a hard time). Lost only about 1 lb the second week.
  • Week 3: Was very sore from workout at end of week 2. Still felt the same overall. Lost about 1lb more. Noticed that while working out at the Gym (HIIT again), my heart rate was much higher and I had a difficult time keeping up with running. My legs were very tired and I was out of breath.

My concerns are:

  1. Why is the heart rate and muscle fatigue getting worse over time. Shouldn’t I be getting stronger/better as I become fat-adapted?
  2. I am able to eat less, but not losing much weight. This is ok for now as I may be retaining water or lactic acid from working out and being sore.
  3. I noticed that my Ketone levels are staying low (about 0.3 mmol/L earlier today). My blood sugar is quite low at 65 earlier, so I know I am not consuming too much carbs or inadvertent sugars. Any explanations for why my ketones are not higher? Could it be because of the extra effort and being sore/fatigued that I am using them up?

(Jack Brien) #15

Keep an eye on your blood pressure and take more salt. Insulin is a salt retaining hormone that acts on the kidneys. Supposedly the situation improves as you become fat adapted. The Salt Fix is a good book


I listened to the podcast on my run today, Peter Defty brought up some eye opening points, and it made a lot of sense. He backed up his information well and I am inclined to believe everything he said, it answers most of my questions that is for sure. I also listened to the next podcast where Brad Kearns contradicted some of what Peter Defty said, mainly that training HR can be 15-20 beats higher in low carb runners and that one could raise there training zones accordingly. I have never been in much agreement with Brad Kearns’ training philosophy and do not agree with his contradictions.

Thank you Sasquatch for recommending this podcast to me, it has helped me a lot and answered a lot of my questions.


Pefrat. From what I have been reading over the last few days, this is not at all uncommon in low carb / keto runners. I think you should not worry too much about the higher HR. Listen to the podcast that Sasquatch recommended, it will answer some of your questions. But to your question 1) This is what is happening to me too, I am hoping that fat adaptation is different for everyone and some are adapted quickly and some not. I also believe it is an ongoing process and adaptation does not reach an end point. It continues over months and years. I guess we just have to be patient. To question 2) I cannot really answer that because I do not know the answer. To 3) This was also happening to me even though my carb intake was below 20 grams a day. The problem I found out was gluconeogenesis. I was consuming way too much protein of which the excess was being converted to glucose. Once I reduced my protein my Ketone levels shot upward immediately.


By the way I took your advice and had a cup of bouillon before my run today and my HR was indeed somewhat lower :slight_smile:


That’s good. Think it was Steve Phinney who said this.

(Candy Lind) #20

I’m chiming in over a month later, but there were a few things that caught my attention here:

@Kiwiness, I want to emphasize that @tdseest recommended checking intracellular and not blood serium electrolyte levels, because that is NOT what the doctor will normally check and it IS what can get royally screwed up on keto. Also, be VERY careful with supplementing potassium. The body will STORE potassium in the cells, given enough salt to control the process, and you can build up too much. This might be part of your heart rate problem if you’re still experiencing it.

@Jack_Brien’s salt advice (in a boullion cube! :stuck_out_tongue_winking_eye:)! I’m no athlete, but it constantly amazes me how much salt my body requires on keto. I routinely drink 4 .75 liter water bottles with 1/8 tsp. of salt added per day to make sure I’m getting enough. Salting my food doesn’t even come close. An athlete will naturally require even more. I agree that the reduction in inflammation lowers your BP, and there is an effect on volume as well. I will repeat the recommendation of “The Salt Fix” and suggest once again an intracellular electrolyte check. I’m very curious about those intracellular levels, if that is not what you tested previously. I hope things are going much better for you by now.

I wonder if @DaveKeto (also a runner, long-distance) had any heart rate and/or electrolyte issues when he started on keto? Maybe he’ll be able to shed some light.