The Aetiology of Reduced Cardiorespiratory Fitness Among Adults with Severe Traumatic Brain Injury and the Relationship with Physical Activity: A Narrative Review

Abstract

Reduced cardiorespiratory fitness or cardiorespiratory deconditioning is a secondary physical impairment commonly reported to affect people after traumatic brain injury (TBI), both in the short-and long-term. Eleven studies have measured peak oxygen uptake (VO 2peak ) to evaluate fitness in this population. The mean (SD)VO 2peak from these studies was 27.2 (6.7) mL.kg −1 ·min −1 , which is markedly below the average fitness level of age-matched healthy individuals. The aetiology of cardiorespiratory deconditioning has not been well evaluated among people with TBI; however, studies on prolonged bed rest and studies on the acute consequences of TBI inform our current understanding. The primary aim of this paper is to present a model to describe the physiological factors contributing to the development of cardiorespiratory deconditioning among people with severe TBI. We propose that both central and peripheral factors contribute to reduced fitness, and that these changes occur because of both the initial brain damage and trauma sustained and the prolonged and initially extreme physical inactivity that is commonly experienced after this type of injury. Reduced fitness can significantly affect the ability to return to pre-injury activities. Given that reintegration into the community is a key goal of rehabilitation among people with TBI, interventions that can prevent or reverse reduced fitness need to be implemented.

The effect of physical activity on health outcomes in people with moderate-to-severe traumatic brain injury: a rapid systematic review with meta-analysis

“…Physical activity can reduce the risk of chronic health conditions for people living with disability and improve overall mood, cognition, and quality of life [7,8]. Except people living with TBI are typically inactive [9][10][11][12] due to injury-related physical and psychosocial outcomes [13,14], and environmental/accessibility barriers to participation [15]. Those who are most profoundly inactive account for a disproportionately high percentage of the deaths [16] and healthcare costs [17].…”

Leveraging Emerging Technologies to Expand Accessibility and Improve Precision in Rehabilitation and Exercise for People with Disabilities

“…Within this population, people with all types of disabilities experience physical, environmental, structural, social, and economic disadvantages that negatively impact their health and quality of life disproportionately, compared to those without disability. Specifically, when considering health disparities, people with disabilities are three times more likely to have comorbidities such as heart disease, stroke, and diabetes [2][3][4][5] and are more than four-fold more likely to experience mental distress compared to those without disability [6]. Moreover, physical disabilities that impact mobility can limit participation in physical activities and exercise [7,8], and, over time, chronic physical inactivity can lead to physiological deconditioning that further impairs physical function and cardiometabolic health [9][10][11][12][13].…”

“…Thus, there is a profound need for accessible and efficacious treatment strategies to improve physical and mental health in people with disabilities, particularly in those with mobility limitations. Physical rehabilitation and exercise training have emerged as promising solutions to improving health, restoring function, and preserving quality of life in populations that face disparate health challenges related to disability [3,5,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Specifically, clinical research studies have shown that rehabilitation and exercise programs provide an opportunity to simultaneously target multiple physiological systems and drive improvements in neural function, cardiopulmonary and metabolic capacity, muscle strength, endurance, flexibility, and vascular health [3,5,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] while also reducing mental distress and attenuating depression and anxiety [14][15][16][17][18]…”

Physical Activity Preferences of People Living with Brain Injury: Formative Qualitative Research to Develop a Discrete Choice Experiment

“…Traumatic brain injury (TBI) is a leading cause of long-term disability globally [ 9 ]. Adults and children who sustain a moderate-to-severe TBI often spend weeks or months in hospital with long periods of physical inactivity leading to reduced cardiorespiratory fitness [ 10 ]. When discharged from hospital, most people with moderate-to-severe TBI are independently mobile [ 11 ] yet continue to be less physically active in the community than their peers [ 12 , 13 ].…”