Why Is Standing Still Worse Than Walking With POTS?

What Changes When You Stop Moving?

It seems backwards that standing in place would be harder than walking, which takes more effort. The difference is where the blood goes. When you're upright, gravity pulls blood down, and your body has to work to keep enough of it circulating to the brain. Walking helps with that. The muscles from your feet all the way up contract with each step and return blood to the heart, so more of it stays in circulation. Stand still and you lose most of that pumping.

The effect has been measured directly. In 20 healthy young adults with a pressure sensor in a leg vein, walking on a treadmill pulled the venous pressure down from its quiet-standing level, the drop was larger at a faster walking speed, and it was smaller when the joints weren't free to move (Kügler, 2001). Quiet standing was the high point for pressure in the leg veins in that study.

Standing still Walking

Is the Muscle Pump Weaker in POTS?

In some people it is. A study compared 12 people who had POTS with low blood flow to the calf against 10 controls and 7 people who had POTS with normal calf blood flow. In the low-flow group, a voluntary muscle contraction emptied 52% of the calf's venous capacity, against 76% in the controls and 80% in the normal-flow POTS group. Their calves were also smaller, 32 cm around against 39 cm in controls (Stewart, 2004). The authors' reading was that less blood flow leads to less muscle, and less muscle leaves a weaker pump.

That finding applied to 1 subgroup. The people with POTS and normal calf blood flow pumped as well as anyone, so a weak muscle pump doesn't explain every case.

Everyone Pools Blood When They Stand. Why Can't Your Body Correct It?

Our team's answer goes a step past the muscle pump. Everybody has blood that pools in the abdomen and the legs on standing. In a healthy system the brain recognizes it, tightens the vessels and squeezes that blood back toward the heart so it keeps circulating, with or without walking. In our team's view the core problem in POTS is on the sensing side: the system isn't detecting the change in blood flow well, so the correction comes late or falls short. Walking covers for the gap by doing mechanically what the reflex should be doing, and standing still removes the cover.

That also explains the heart rate. When less blood returns to the heart, each beat sends out less, and the heart speeds up to keep blood moving to the brain. In our team's view that fast rate is a compensation that's doing its job. How the pooling works is covered in blood pooling in POTS, and what counts as a normal rise is on why your heart races when you stand up.

What Helps When You Have to Stand Still?

The research on this comes mostly from fainting, with very little in POTS. A 2022 review of counter-pressure maneuvers found 45 studies, 12 in people with vasovagal fainting and 1 in POTS. The maneuvers included leg crossing, tensing the legs or the whole body, calf raises, marching in place, tiptoeing and squatting. Across the studies they raised standing systolic blood pressure by 14.8 mmHg on average, and most patients reported fewer symptoms (Williams, 2022).

The mechanism matches the muscle pump. In people prone to fainting on a tilt table, crossing the legs and tensing the muscles raised blood pressure within 3 to 5 seconds, and the whole effect came from the heart putting out more blood (Krediet, 2005). In 24 women whose blood pressure dipped right after standing, tensing the lower body after standing or activating those muscles before standing made the dip smaller and lowered symptom scores (Sheikh, 2022).

• Shift and march. Rock from foot to foot, rise onto your toes or march in place to keep the calves contracting.
• Cross and squeeze. Cross your legs and tense your thighs and buttocks.
• Compress. Waist-high or abdominal compression does part of the same job from the outside. Compression for POTS covers what the trials show.

Those will get you through a line. Our team's advice is to treat them as a bridge and keep asking the harder question, which is why your body isn't making the correction without help. A shower chair, a stool in the kitchen and a list of tricks are all ways of living around the problem, and the time is better spent finding out what's failing and working on it. How our team thinks about exercise once you're ready is on why standard exercise advice fails in POTS.

Standing Still and POTS: FAQ