David William McMillan

University of Miami | UM · Miami Project to Cure Paralysis

Background: A spinal cord injury (SCI) from trauma or disease impairs sensorimotor pathways in somatic and autonomic divisions of the nervous system affecting multiple body systems. Improved medical practices have increased survivability and life expectancy after SCI allowing for the development of extensive metabolic comorbidities and profound ch...

Psychedelic-assisted therapy (PAT) may treat various mental health conditions. Despite its promising therapeutic signal across mental health outcomes, less attention is paid on its potential to provide therapeutic benefits across complex medical situations within rehabilitation medicine. Persons with spinal cord injury (SCI) have a high prevalence...

The sensorimotor dysfunction caused by cervical and thoracic spinal cord injury (SCI) is concomitant with sympathetic nervous system dysfunction, evidenced by the high prevalence of orthostatic hypotension and autonomic dysreflexia. Although the International Standards for Neurological Classification of SCI evaluate sensorimotor function both above...

Astorino, TA, Robson, T, and McMillan, DW. Classifying intensity domains from arm cycle ergometry differs versus leg cycling ergometry. J Strength Cond Res 37(11): 2192–2199, 2023—This study compared the distribution of exercise intensity domains in response to progressive leg cycle ergometry (LCE) and arm cycle ergometry (ACE). Seventeen active me...

In recent decades, vagus nerve stimulation (VNS) therapy has become widely used for clinical applications including epilepsy, depression, and enhancing the effects of rehabilitation. However, several questions remain regarding optimization of this therapy to maximize clinical outcomes. Although stimulation parameters such as pulse width, amplitude,...

Individuals with spinal cord injuries (SCI) commonly present with component risk factors for cardiometabolic risk and combined risk factors for cardiometabolic syndrome (CMS). These primary risk factors include obesity, dyslipidemia, dysglycemia/insulin resistance, and hypertension. Commonly referred to as “silent killers”, cardiometabolic risk and...

Introduction/objective: Reduced cardiovascular function is common following high spinal cord injury (SCI), yet it is unknown whether cardiac structure and function are related to SCI-induced changes in body composition and metabolic profiles. The objective of this study was to examine the correlation between cardiac structure and function and body...

Among 1299 older adults with 24-h Holter monitoring data at baseline, followed for approximately 15 years, 190 incident hip fractures occurred. Increased heart rate variability was independently associated with reduced risk of hip fracture among female participants.PurposeAutonomic nervous system function modulates bone remodeling in rodent osteopo...

Many persons with spinal cord injury (SCI) have one or more preventable chronic diseases related to excessive caloric intake, and poor eating patterns. Appropriate nutrient consumption relative to need becomes a concern despite authoritative dietary recommendations from around the world. These recommendations were developed for the nondisabled popu...

Context: Persons with spinal cord injury (SCI) present with low fat oxidation that is associated with poor cardiometabolic health. This study compared changes in fat and carbohydrate (CHO) oxidation during moderate intensity continuous exercise in persons with SCI and able-bodied adults (AB). Design: Repeated measures, within-subjects study. Se...

Spinal cord injury (SCI) results in a multitude of metabolic co-morbidities that can be managed by exercise. As in the non-injured population, manipulation of exercise intensity likely allows for fruitful optimization of exercise interventions targeting metabolic health in persons with SCI. In this population, interventions employing circuit resist...

The peak rate of fat oxidation (PFO) achieved during a graded exercise test is an important indicator of metabolic health. In healthy individuals, there is a significant positive association between PFO and total daily fat oxidation (FO). However, conditions resulting in metabolic dysfunction may cause a disconnect between PFO and non-exercise FO....

Abstract Background: Environmental crises are a threat to all, but certain populations and regions are disproportionately affected by extreme weather events. For people living with disability, South Florida’s sociogeographic characteristics make it a desirable place to live. However, for five months of the year the Atlantic hurricane season challe...

Abstract Objective: Spinal cord injury (SCI) results in dysregulation of fat metabolism that leads to hypertriglyceridemia following ingestion of food (“postprandial lipemia”; PPL). It is not known if aberrant endogenous postprandial triglyceride responses, as in other populations, contribute to PPL in SCI. Further, predictors of postprandial fat...

Introduction Whole body energy expenditure and lipid oxidation (Lox) are upregulated during and after exercise. Persons with spinal cord injury (SCI) generally have a blunted ability to utilize fat during exercise, but it is unknown if their substrate partitioning is affected during recovery from exercise. Purpose To determine the effect of a sing...

Spinal cord injury (SCI) results in dramatic changes in body composition, with lean mass decreasing and fat mass increasing in specific regions that have important cardiometabolic implications. Accordingly, the recent Consortium for Spinal Cord Medicine (CSCM) released clinical practice guidelines for cardiometabolic disease (CMD) in SCI recommendi...

Spinal cord injury (SCI) results in an array of cardiometabolic complications, with obesity being the most common component risk of cardiometabolic disease (CMD) in this population. Recent Consortium for Spinal Cord Medicine Clinical Practice Guidelines for CMD in SCI recommend physical exercise as a primary treatment strategy for the management of...

Spinal cord injury (SCI) results in disordered fat metabolism. Autonomic decentralization might contribute to dyslipidemia in SCI, in part by influencing the uptake of dietary fats through the gut-lymph complex. However, the neurogenic contributions to dietary fat metabolism are unknown in this population. We present a subset of results from an ong...

EWGSOP2 cutoff values for CS and WS are significantly associated with hip fracture risk in men, while the association with GS differed by age. In women the WS cutoff level was associated with risk of hip fracture. These results show that EWGSOP2 cutoff values, both as stand-alone measures and as a composite score, could identify hip fracture risk i...

Purpose: The purpose of this study was to assess the acute effects of exercise mode and intensity on postprandial macronutrient metabolism. Methods: Ten healthy males age 39 ± 10 yr with chronic paraplegia (13.2 ± 8.8 yr, ASIA A-C) completed 3 isocaloric bouts of upper-body exercise and a resting control. Following an overnight fast, participant...

Randomized crossover. To test differences in the duration and magnitude of physiological response to isocaloric moderate intensity continuous (MICE) and high-intensity interval exercise (HIIE) sessions in persons with spinal cord injury (SCI). Academic medical center in Miami, FL, USA. Ten adult men (mean ± s.d.; 39 ± 10 year old) with chronic (13....

2112 Board #31 May 28 2:00 PM - 3:30 PM

Introduction: Following spinal cord injury (SCI) lower extremity bone mineral density (BMD) losses are as high as 40% due to mechanical unloading and autonomic dysfunction. While lumbar spine (LS) BMD appears to be relatively spared, evidence suggests BMD by dual-energy radiographic absorptiometry (DXA) may overlook bone pathology in this region. T...

Background: Chronic spinal cord injury (SCI) increases morbidity and mortality associated with cardiometabolic diseases, secondary to increases in central adiposity, hyperlipidaemia and impaired glucose tolerance. While upper-body Moderate Intensity Continuous Training (MICT) improves cardiorespiratory fitness, its effects on cardiometabolic compo...

P141

Med Sci Sport Exerc; 51(Supplement):748 2671 Board #335 May 31 11:00 AM - 12:30 PM

A sedentary lifestyle occurring soon after spinal cord injury (SCI) may be in contrast to a preinjury history of active physical engagement and is thereafter associated with profound physical deconditioning sustained throughout the lifespan. This physical deconditioning contributes in varying degrees to lifelong medical complications, including acc...

Med Sci Sport Exerc:49(suppl);630

Objective: When matched for charge input, determine if caloric (kcal) expenditure and fuel partitioning measured during and immediately following a bout of functional electronic stimulation (FES) cycling differed when performed on two FES devices. Design/Method: Four males with spinal cord injury (SCI; age: 43±15 yr; weight: 77±6 kg; level of injur...

Persons with spinal cord injuries and disorders (SCI/D) frequently experience component and coalesced health risks of the cardiometabolic syndrome (CMS). The CMS hazards of overweight/obesity, insulin resistance, hypertension, and dyslipidemia—the latter as depressed high-density lipoprotein cholesterol and elevated triglycerides—are strongly assoc...

Homo sapiens constitute the only currently obligate bipedal mammals and, as it stands, upright bipedal locomotion is a defining characteristic of humans. Indeed, while the evolution to bipedalism has allowed for the upper limbs to be liberated from ground contact during ambulation, their role in locomotion is far from obsolete. Rather, there is rea...

Med Sci Sport Exerc. 2016;48(suppl):1025.

Interappendicular Neurological Coupling During Various Locomotor Tasks In Persons With Spinal Cord Injury

The purpose of this master's thesis was 1) to examine the effect of active arm swinging on electrical activity of leg musculature during assisted locomotor training in persons with spinal cord injury (SCI), and 2) compare persons with SCI to neurologically intact controls.

This study examined acute and chronic changes in perceptual measures (rating of perceived exertion (RPE), affect, and arousal) in response to two regimens of high intensity interval training (HIIT). Twenty three healthy sedentary women (mean ± SD age and VO2max = 23.0 ± 5.7 yr and 30.1 ± 4.4 mL.kg.-1.min-1, respectively) were randomized to complete...

Med Sci Sport Exerc. 2015;47(suppl):152.

Recently, a self-paced protocol demonstrated higher maximal oxygen uptake versus the traditional ramp protocol. The primary aim of the current study was to further explore potential differences in maximal oxygen uptake between the ramp and self-paced protocols using simultaneous measurement of cardiac output. Active men and women of various fitness...

Med Sci Sport Exerc. 2014;46(suppl):342.

Med Sci Sport Exerc. 2015;46(suppl):342.

Purpose: This study aimed to compare changes in maximal oxygen uptake (VO2max) in response to two regimens of chronic interval training. Methods: Twenty healthy sedentary women (mean ± SD age and VO2max = 23.0 ± 5.7 years and 30.1 ± 4.4 mL kg(-1) min(-1), respectively) were randomized to complete 12 weeks of one of two interval training regimes,...

Med Sci Sport Exerc. 2013;46(suppl):1133.

Introduction: The primary aim of the current study was to determine the effect of two doses of chronic high-intensity interval training (HIT) on changes in maximal fat oxidation (MFO) and body composition. Methods: Sedentary women (N = 23, age and V˙O2max = 24.2 ± 6.2 yr and 30.3 ± 5.2 mL·kg-1·min-1, respectively) completed either high (HI) (80%...

Humans demonstrate an innate desire to synchronize stepping when walking side by side. This behavior requires modification of each person's gait, which may increase for pairings with very different walking patterns. The purpose of this study was to compare locomotor behavior for conditions in which partners exhibited similar and sub-stantially diff...