Most individuals with spinal cord injury (SCI) retain spared neural activity at and below the site of injury, activating these neural circuits may enhance neural plasticity to promote recovery of motor, sensory, and autonomic function. Individuals with SCI struggle with life-long autonomic nervous system (ANS) dysfunction with serious adverse consequences. The dynamic balance between the sympathetic and parasympathetic branches of the ANS is impaired in individuals with SCI at or above T6, which negatively impacts internal homeostasis during daily activities such as transferring from the supine to the seated position, regulating core body temperature (Tcore), and exercise performance. For the estimated millions of people living with SCI globally, impaired ANS regulation is common, and has been implicated in widespread cardiovascular complications, which are a leading cause of morbidity and mortality in this population. One of the most prominent consequences of cardiovascular ANS impairment is blood pressure (BP) instability, which includes hypotension, orthostatic hypotension (OH), and autonomic dysreflexia (AD). These BP impairments lead to an absence or reversal of the nocturnal BP dip, and increased daytime sleepiness, which detract from wellbeing, independence, social engagement and quality of life. Further, ANS cardiovascular impairment in athletes with SCI limits the heart rate (HR) response during competition, lowers BP, and increases fatigue, thereby compromising endurance and sports performance. In fact, some athletes with SCI enhance their performance in competition by self-inducing AD, a practice known as “boosting,” to increase BP and create a generalized efferent sympathetic response. In addition to cardiovascular complications, ANS deficits post-SCI also contribute to abnormal sudomotor function and dysregulation of Tcore. With climate change becoming increasingly apparent, the effects of wide variation in environmental conditions are anticipated to be more severe and more devastating to overall health, independence, and quality of life in individuals with SCI who lack adequate ANS thermoregulatory control. For these reasons, individuals with SCI prioritize restoration of ANS functions higher than regaining the ability to walk; however, there are no clinical interventions proven to be safe and effective for managing widespread ANS dysfunction following SCI. This project will focus on using non-invasive, transcutaneous spinal cord stimulation (TSCS) to restore intrinsic ANS control of BP and determine the effects on exercise endurance and Tcore. A recent report found that the use of TSCS in 6 individuals with cervical SCI (C3-C5) improved ANS regulation of HR, sudomotor, thermoregulation, and bladder control and a separate team found that TSCS restored ANS control of orthostatic BP, cardiac contractility, and cerebral blood flow velocity in 5 individuals with chronic motor-complete SCI (C5-T2). Most recently, the safety and efficacy ...