RHR Plummeting Over One Week

[Graceoneil]

So, my RHR, on average, is normally something like 70-75. I've had my Fitbit almost a year, and on better or worse months, it can fluctuate up or down a few beats.

But, all of a sudden, over only one week, it has just plummeted from 73 to as low as 52 this morning. I have been doing lots of Zone minutes, but not super consistently -- let's just say I'm not on the treadmill at 8am or anything, I just do taxing activities, like shoveling the walk. Also, it feels fake because my Zones have all dropped significantly.

Trying to look this up is impossible, because it's mostly people who have it steadily go down over time because they're exercising, or talking about bradycardia. I wouldn't say 20 beats down in a week is a natural drop.

Could it be due to stress or bad sleep? I've been a bit iffy this week on both of those things, but I feel like the RHR would go up, not down? I am so confused. Has anybody else had this happen??

If it helps, I'm 23 and average BMI.

[t.parker]

It looks more like a device error (although it isn't impossible). Your zones will change based on that because now Fitbit uses HRR (reserve) to estimate your zones and it depends on RHR and MaxHR.

About bradycardia, if you are able to elevate your HR then it's all fine. People with bradycardia have a block preventing their heart to beat faster and it results in delivering not enough oxygen (so you may experience dizziness or even faint). My cardiologist gave me an interesting analogy. The heart and nervous system work like a gearbox in the car. With bradycardia, the link between brain and heart is broken and your heart cannot shift to the higher gear when your body needs more oxygen. If you feel alright then don't stress yourself too much about it.

Fluctuations of several beats even over one day are nothing unusual. I registered drops of 55 to 48 within one day, or an increase of 37 to 52 within 2 days (I think it was when I had Covid and extremely bad sleep). Dropping RHR is usually a good sign (if it's not a device error). My current RHR stays at 35-37 and is more or less stable but it doesn't mean really anything. Look at the big picture (over a span of weeks rather than days) because time smoothens potential reading errors.

[y2kcrash]

Wouldn't hurt to have your

TSH checked

[y2kcrash]

Also have you done an actual 60 second HR count manually to confirm the Fitbit results

[emili]

@Graceoneil hey there..totally understand the concern. Matters of the heart are always scary. I think if your RHR significantly increased, push the panic button, but a decrease is usually a good sign unless you don't feel well when it drops that low. If it is weighing on your mind, call your doctor for a consult. I am sure you will feel better when someone with an actual medical degree tells you not to worry. I would also take the advice of manually checking your HR first thing in the morning when you wake up. Look what your tracker shows and manually take the beats to see if it is within a few beats of accuracy. Just to rule out that your tracker isn't giving you false readings.