Summarize this content to 2000 words in 6 paragraphs Standing continuously for too long can inflict sore feet, lower back pain and stiffness in the hips, back and shoulders. The legs and ankles swell as gravity causes blood to pool in the lower extremities.“There appears to be general agreement among the study findings that prolonged standing without dynamic movement, even for periods as short as 30 minutes, leads to physical fatigue, discomfort, and pain in several body regions,” a review of research into the health effects of standing for long periods reported in 2015.Texas senator Ted Cruz’s advice Booker: “Wear comfortable shoes and don’t drink water.”Credit: APLong-term impacts of standing up too long without respite include a greater risk of varicose veins and chronic musculoskeletal pain. One study found people should avoid standing for longer than 40 minutes without a break.And aside from the physical pain, there’s what’s happening in Booker’s brain. He reached the 24-hour point without sleep, which brings about drowsiness, impaired judgment, reduced co-ordination and the release of stress hormones cortisol and epinephrine.That level of sleep deprivation is comparable to having a blood alcohol reading of 0.1, according to the US Centres of Disease Control.Dr Garston Liang, a workload expert at Newcastle University, described Booker’s speech as a “gargantuan” cognitive effort.“From a cognitive perspective, I’d say this person is a bit of an outlier,” he said. “You’re straining a lot of mental resources that you might have only a limited amount of. And for this individual, they’ve clearly pushed through usual signs of exhaustion, attention and fatigue to try to achieve a political outcome.”The exorbitant mental workload and lack of sleep will cost Booker in coming days, Liang said, as the intense drain on mental resources blunts his “ability to operate normally” as he recovers from the 25-hour feat.The Morning Edition newsletter is our guide to the day’s most important and interesting stories, analysis and insights. Sign up here.