I'm not sure if it has any relation to POIS, but I believe that I may have Hyperkalemic Periodic Paralysis. Starting about a year ago, I noticed that I would experience sudden episodes of leg weakness that would last a few hours. The weakness was very much noticeable when I would squat, sit, or walk down stairs. When engaging in these activities, my legs would feel incredibly weak and rapidly shake up and down. I also noticed some cognitive impairment during these episodes (bad memory, poor concentration, confusion). I went to a neurologist and had a CBC, and and EMG done and nothing showed up. Over time, I noticed that the main trigger for the episodes was the consumption of nicotine. It didn't matter if it was a cigarette, gum, or an e-cig. Nicotine seemed to precipitate an episode quite frequently. I have taken various other psycho-stimulant drugs such as Ritalin, Adderall, and Caffeine without them causing an episode. It also seemed like the episodes became more severe and frequent during POIS, a night after drinking, or after stressful situations. After doing a little bit of research, I came across a disease known as "Hyperkalemic Periodic Paralysis". In this disease, muscles are affected by an improper regulation of Sodium and Potassium. Excess sodium flows into the muscles and potassium is drained from the muscles. This leads to a drop in serum sodium levels (hyopnatremia), which may lead to neurological changes and the lack of potassium in the muscles leads to weakness. Smoking, stress, and alcohol consumption are listed as common triggers of episodes in people with the disease. One of the ways to prevent an attack is to consume carbohydrate rich foods when one feels an attack coming on. I often crave sugar when experiencing an episode.