General Mechanical Principles for Living in a POTS Body

There are two important principles for living in a POTS body:

1. Shorter is better

POTS is, at its core, a physics/fluid dynamics problem. It is hard to pump fluid up. The higher you have to pump, the harder it is. It takes very little effort to pump blood around the body when it is horizontal, but a lot when it is vertical. So one solution to this is to reduce the vertical distance your heart has to pump blood. Sitting is one way, but as I often say, sitting is still semi-upright. Lying down is even better.

One thing many people don’t realize is that putting your arms over your head, or even just bringing them up rather than letting them hang, increases the amount of volume that needs to get pumped back up. A lot of people complain about shampooing their hair; having your arms up, in combination with the vasodilation caused by hot water and the standing still you do in the shower, is why this completely does some people in.

2. Legs and core, engage!

The formal tilt table test has, until recently, been considered the gold standard for POTS diagnosis. The purpose of this test is to isolate the action of the hemodynamic system (the heart and blood vessels and blood volume) from the actions of the leg, butt, and core muscles, which, in everyday life, assist the heart in pushing blood around the body. Other versions of orthostatic testing, now preferred for diagnosis, also attempt to minimize muscle involvement. What this tells us is that engaging the leg, butt, and core muscles does something: it can reduce tachycardia and improve our tolerance for standing, and this is the logic behind countermaneuvers, in which we intentionally engage these muscles to better tolerate standing and prevent fainting. The principle here is: muscle engagement good, muscle laxity bad.

Scenarios

So let’s look at some common scenarios I (and many other people) deal with, both in terms of verticality and muscle engagement.

Grocery shopping is my nemesis. Two things are going on here: I’m walking around tall, and my muscles are super lax because I am moving at “browsing speed.” You don’t move fast in a grocery store — you mosey, and you stop frequently to look at and pick out items. You may even reach up on high shelves. And then you go stand in line. It’s bad, really bad. The same goes for browsing bookstores, antiquing, farmers’ markets, and thrift stores, and other forms of shopping. Museums can also be pretty taxing. It sucks that so many enjoyable things are done at “browsing speed.”

Cooking and washing dishes are quite similar to grocery shopping; kitchens are designed to have everything within arms reach, so we don’t move much and just stand a lot. We may also need to reach things stored high in cabinets.

Sitting to work is not terrible, but sitting is still semi-upright. I often sit cross-legged in my desk chair for this reason; this vastly reduces how tall I am. Another alternative would be to put my feet up. My recliner and a lap desk and laptop offer a third alternative. Interestingly, though, I’ve noticed another thing I do while sitting in my desk chair, and that is that I have my feet under me, on the floor or up on the base of my desk chair, actively pushing down. This engages my leg muscles in ways regular sitting would not. I only noticed this after a lengthy experience with the scenario that follows: riding in a car.

Riding in a car is something I don’t do a lot of; I largely walk and use transit. But we recently took a lengthy road trip and the amount of extra medication I had to take just to sit in a car for hours was wild. But I know why: unlike sitting at my desk, I cannot sit crosslegged in the car, nor can I sit with my feet under me, engaging my muscles. At best, I could lower my seat to reduce how tall I was, wear compression, and hydrate like mad. Driving adds slightly more muscle engagement, but not a lot.

Martial arts training is something I tolerate surprisingly well, for, I suspect, two reasons: our low stances make us quite a bit shorter, and my leg, core, and butt muscles are always engaged even when we are not moving. Our arms also tend to stay close to the body, at or below shoulder height. I was training judo while undiagnosed and unmedicated before the pandemic, and, while it was tiring, our focus on groundfighting (newaza) was the best case scenario for my POTS body.

Regular standing is not as terrible for me as it used to be, because I took lessons from my martial arts training and got in the habit of always standing with “soft knees” and tail tucked (pelvis rotated back, shortening the distance between the pelvis and the ribcage), which makes me ever so slightly shorter and increases my muscle engagement in my legs and core. It is tempting to lean against things, but standing under my own power actually makes me less tired. Another thing I did was go back to wearing Vibram Fivefingers as street shoes because they encourage me to move around more and thus engage my muscles more, even as I stand in one place.

I hope this helps explain why some seemingly easy activities are paradoxically more difficult than others, and gives you some ideas on how to improve your body mechanics in order to better tolerate your daily activities, as well as get a sense in advance of how different activities might affect your body.

Note: I originally posted this to the POTS subreddit on 24 Mar 2024, but neglected to also post it here at the same time.