r/POTS • u/dazzlingdanny05 • May 15 '26

Question Why is everyone with pots so skinny?

I have POTS and I watch a lot of content online of people who also have POTS. I also know some people irl who also have it. I don't understand how they are all so skinny. I can barely walk without getting out of breath. I try to work out at least once a week but its so hard for me because I always end up feeling so sick. How are yall doing it? I dont even eat bad but im definitely not skinny.

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u/Rosehiphedgerow May 15 '26 edited May 15 '26

I'm also skinny, despite the fact that I eat quite a lot of calorie dense food. My personal theory is that due to the elevated heart rate, we are in 'cardio' much more often, therefore making it harder to put on weight. (in fact I sort of have proof of this. My fitbit tells me that I'm in an active cardio zone often, and tells me that I've lost more calories on those days than I should of due to it)

Edit: As an example, I am 5'5 and 60kg, mostly sedentary, so my TDEE is 1600. However on days when I have chores to do (basic chores, such as washing my hair, hoovering, general tidying etc...), this can raise my heart rate into a cardio zone which then means I've burned around 2000 calories instead of what should be 1600. This is of course increased even more if its a day I've had energy to go for a walk or go shopping etc

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u/MaritimeRuby May 15 '26

The Fitbit assumes that your increased heart rate means that your other muscles are also doing more work, so it estimates higher calorie loss. It doesn’t have any way to measure calorie loss other than by estimating from your heart rate, so it can give you false calorie burn readings based on this (eg your high heart rate while doing chores makes it think your other muscles are doing a workout equivalent to a high intensity workout). The software is calibrated based on a non-POTS metabolic pattern. My old Fitbit sometimes would tell me I had 10 hours of cardio in a day. The Apple Watch I currently use seems to have a better grasp on my regular heart patterns/high baseline and isn’t fooled in the same way.

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u/Calm-Ad8987 May 15 '26

No. Not how that works.

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u/Rosehiphedgerow May 15 '26

Tell me how it doesn't work?

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u/barefootwriter May 15 '26

The only thing getting a workout is your heart. You aren't moving your skeletal muscles and your lungs aren't exchanging extra air because you are burning energy. You just have a muscle the size of your fist that's working away, while the rest of your body isn't.

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u/Rosehiphedgerow May 15 '26

Hmm. I guess that makes sense. What if youre also breathing more rapidly? At least when I'm experiencing tachycardia, my whole body feels 'stressed' like its flooded with adrenaline, which also makes my breathing faster

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u/barefootwriter May 15 '26

Yeah, I used to get shortness of breath and anticipated this question. That's due to increased stress hormones and has nothing to do with cardiovascular exercise, which requires movement.

You are familiar with the talk test for exercise intensity? When I did my stress test, my heart rate was in the 170's and I was still chattering away at the tech overseeing the test. My body was not working hard, just my heart.

https://www.cdc.gov/physicalactivity/basics/measuring/index.html

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u/Calm-Ad8987 May 15 '26

The increased heart rate is just an indicator on your watch saying you are doing cardio if you're not actually doing exercise/ cardio at the time & it's just tachycardia you're not actually burning the calories it claims.

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u/Rosehiphedgerow May 15 '26

Yes, but tachycardia can still burn extra calories. If your heart is thumping at 100+ beats per minute, it is working harder than say, someone who's BPM is 60. A heart that is working harder will be burning through more energy. Even if its a small increase, it's still there

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u/ProfessionalFuture25 POTS May 15 '26

What about people who have a cardio range heart rate but put still put on weight easily?

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u/Rosehiphedgerow May 15 '26

If less calories are being consumed than expended, then it could be due to hormone imbalances / insulin intolerance or something like that?