Subjects
hypermobility, hypermobility spectrum disorder, hEDS, orthostatic hypotension, orthostatic intolerance, hypermobile hEDS, POTS
HEDS, ORTHOSTATIC HYPOTENSION
Sixty individuals diagnosed with POTS by positive tilt table or autonomic reflex screen where they had met diagnostic criteria for POTS with heart rate increase of 30 beats per minute (bpm) or more, or over 120 bpm, within the first 10 min of standing or assuming an upright posture, in the absence of orthostatic hypotension and had been experiencing chronic symptoms of orthostatic intolerance for at least 6 months agreed to participate in this study. Exclusion criteria included (1) pregnancy or (2) regularly active (more than 30 min/week of structured moderate intensity aerobic exercise). Subjects were randomized to either the ET or SOC groups. Patients with hypermobile hEDS were eligible to participate, but because these patients have their own unique challenges regarding exercising, randomization was also stratified on the basis of whether the individual had hEDS or not to ensure equal distribution of those who had both POTS and hEDS between the ET and SOC groups. Classification of hEDS was confirmed by a documented clinical diagnosis; if there was no clinical diagnosis, participants who reported hypermobility were classified as having hypermobility spectrum disorder. All participants were asked to not take any medication that can affect their autonomic system for more than 24 h if feasible, if not they were evaluated under identical conditions (