Rising resting heart rate due to HIIT

[vlaura]

I started doing high intensity interval trainings (HIIT) at the end of the January and I've noticed that my resting heart rate has slowly gone up (each day a little) from a regular 69-70 to a 79 (today). I'm 21, and usually do my HIIT workouts 2 days in a row and then rest 1 day. Workouts are approximately 40-60 min.

Is this something normal or should I be worried and take a bit longer breaks (although I feel totally fine)?

[bayman099]

Hi:  I do no think there is anything to worrry about at all/.

[JohnRi · Accepted solution]

Yeah, I think you should stop the HIIT altogether, and work on your cardio.  You should only do HIIT if your resting heart rate is 65 or lower.  This is from a website...

"Experienced exercisers seeking general fitness should take this simple test: Sit quietly, find your pulse, and count your heartbeats for one minute. If your resting heart rate is below 60, feel free to experiment with HIIT. “If it’s above 65,” says Robertson, “you need steady-state cardio training.” Drop other cardio activities and follow the recommendations for beginners.

Once your aerobic system is up to snuff, dial back the steady-state training and switch to HIIT. Make sure, however, that your resting heart rate stays below 65 beats per minute. If it shoots above 65, return to aerobic work and limit HIIT."

You can read more, at https://experiencelife.com/article/steady-state-cardio-vs-high-intensity-interval-training/

But if you are in good health, the steady climb is a sign you need to do more cardio get your rate down to 65 or lower.  Mine is 63 from walking for around 90 minutes 3 times a week, for 5 miles.  About to switch to walking 3-4 miles every day.  And hopefully switching to running after that...

Exercise should reduce your resting heart rate, not increase it, so be careful.  Good luck...

[Dominique · Accepted solution]

Based on my own experience (Fitbit Surge, about 1 year), a variation of 10 bpm in the resting HR as reported by Fitbit is very unusual. I saw it  for the first time last month: like you, my resting HR slowly increased from its normal 59-61 to 70, a level I had never seen before. I wasn’t sick per se, but probably unusually stressed. Since then, it has gone back to its more normal level.

Based on the precautionary principle, I would interrupt HIIT sessions for a while and see if the resting HR returns to its usual range. Better safe than sorry.

[emili]

there are as many articles that say stop as there are that say keep going. the one that stuck out to me was the one that said not to do it too long and not too close together. It recommended a month, twice per week-- not back to back days. Maybe it would be beneficial for you to stop for two weeks or so, see where your HR is and then go back but do it maybe tuesday and friday only with some other cardio or strength training in between....

[vlaura]

Yeah, I haven't been sick for a long time and my other health stats are all good, so I consider myself quite  healthy. 🙂

Although, I have been more stressed lately due to the beginning of a new semester at the university, but I don't think it has an impact on my resting heart rate (maybe it has). I'll try to make HIIT workouts once or twice a week from now on to see whether my resting heart rate drops a little.

[mbach]

When i first started working out regularly about 7 years ago i also had a pretty physical job and i notiecd if i did more than 3 classes a week or too many days in a row my resting heart rate was higher than normal. My resting rate for years has been 58-60 even after coffee or some exertion. SO i gave myself a rule back then that if I noticed that 10 point increase i would tak a few days off. I have had the surge since december and it is amazing to me that my HR is pretty low and  even in workouts i have difficulty keeping over 120. So the 10 point rule is a good one. Over trainning leads to injuries and depletion of all kinds of ggod stuff in our bodies. I have lasted because i listen to my body.

[vlaura]

Since I've reduced the amount of HIITs my resting heart beat has been quite stable (70 or 71bpm). So I guess taking longer breaks helps. 🙂

[keeponsteppin]

My guess is that your workout sessions were very intense and your body was in recovery mode.

Keep doing the HIIT once your heart rate has returned to normal.  This may take a few days.

[Mintyfresh24]

I know this post is old....but HIIT will usually cause your heart to be a little higher than normal for 24-36hrs after your session. Your body is essentially in an oxygen deficit from the work out, so it is burning more calories and your heart rate is likely elevated while "recovering" the next day (look up EPOC). If you do HIIT regularly it may APPEAR that your resting hr is increasing from where you started, but if you ever take a break you should see it fall back down (if you don't do the session you won't see the oxygen deficit and therefore wont see the heart working as hard to recover) This is completely normal. In fact it's one of the perks of HIIT training in itself. I definitely recommend a rest day between HIIT sessions to make maximum use of the calorie burn though, and the recovery day ensures you can give peak performance on your next session.