I've had POTS for more than 10 years now, since I had babies. Before POTS, I did sports galore to a very high level, did core and pilates regularly, I was really fit, into skydiving and scuba diving. I used to swim like a fish right up until the birth of my first child. Few weeks after his birth, I took him to his first swim lessons, I couldn't get out of the pool and walk properly, ridiculous exhaustion, legs feeling like lead. Thought it was just to do with the recent c-section, breastfeeding, tiredness etc. I had to have my Mum come with me to drive me home because I'd walk in and then crawl out. My POTS symptoms became more severe over time and really accelerated after my second baby. Soon I was having spells of being bedbound and having to use a wheelchair to get about. Eventually, I got so deconditioned that to get back to anywhere normal, I started with rowing, along the lines of the Levine protocol. I did loads of mindfulnees/breathing and meditating stuff. I used some special glasses and an earplug that helped desensitise me to certain stimuli (complex background info but this was really helpful) It took months but eventually I did my first run for 1 minute and 18mths later did my first 'fun run' of 2.5km. I'm back in work and exercising regularly these days. But I still can't crack this pool thing. I get similar when I fly and we circle, I pass out on descent and sometimes have to be carried off the plane. At nearly all other times I feel pretty normal. Doesn't matter if I swim or float I still have problems but I did see a brain training guy who suggested that I don't dive in, nor float, just get in steady, swim reasonably fast and then get out. This definitely helps. He reckons if I keep going, my brain will adapt. But I'm yet to find a window when I can be that incapacitated for long enough to crack it properly. If anyone finds the/an answer, please post!