Effects of detraining on health indicators in people with spinal cord injury
Authors:   , Almada Lucas Barbosa 
Published: July 2024

Spinal cord injury (SCI) is a debilitating condition that causes motor, physiological, and sensory impairments, potentially leading to permanent disability, increased morbidity, and mortality, ultimately impacting an individual's quality of life (QoL). Physical exercise emerges as an effective alternative to mitigate these consequences and uphold the autonomy and QoL for this population. Detraining (DT), defined as the partial or total loss of adaptations induced by physical training in response to its complete interruption or insufficient stimulus, represents a significant concern. This thesis focuses on the impact of DT on health indicators in individuals with SCI. Two studies were conducted, a systematic review and an observational study, aimed at (1) verifying the state of the art regarding DT in individuals with SCI; and (2) To elucidate the long-term effects of DT on muscle strength (MS), functional capacity (FC), mental health (MH), and body composition (BC). The first study is a systematic review following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The investigation utilized databases such as PubMed, Web of Science, Embase, SPORTDiscus, and Cochrane, employing pertinent English keywords related to "Detraining" and "Spinal Cord Injury" along with their respective synonyms. Owing to the scarcity of research in this area, no timeframe was established for the eligibility of studies. The search, conducted in November 2023, initially identified 42 studies, which was narrowed down to 15 after removing duplicates. Post-title analysis, two more studies were discarded. Of the 13 abstracts scrutinized, seven were further excluded, leaving a total of six for in-depth analysis. The unique characteristics of these studies precluded the execution of a meta-analysis. As results DT seems to impact on health reducing cross-sectional muscle area, maximum oxygen uptake (VO2peak), altering BC and metabolic profile. In chapter II, the aim of the observational study was to assess the impact of DT during the pandemic on five individuals with thoracic SCI. Evaluations of MS, FC, BC, and MH were conducted using techniques such as strength assessments, DEXA scans and mental health surveys focusing on anxiety and depression. After a 33-month period of DT, notable decreases in functional agility and MS were observed, accompanied by an aggravation of anxiety and depression symptoms. Variations were seen in the total body mass and fat mass across participants. The outcomes regarding lean body mass also showed diversity, with one subject experiencing considerable decline. DT led to significant changes in BC when training was realized by inactive muscles, characterized by an increase in body fat and a decrease in muscle mass, particularly after ceasing testosterone-related training. This cessation of exercise regimens also notably impacted metabolic profiles, causing alterations in glucose levels, lipid profiles, and insulin sensitivity. Additionally, changes in hemodynamic factors, such as blood pressure and heart rate, were observed, increasing the risk of cardiovascular issues. A reduction in VO2peak was also evident following the DT period, indicating cardiorespiratory decline. Concurrently, the DT period during the pandemic resulted in a deterioration of both physical and mental states in individuals with SCI, underscoring the necessity of regular exercise for this group. This highlights the importance of personalized evaluations to fully understand the effects of DT, emphasizing the critical need for sustained physical training to mitigate adverse health outcomes. Keywords: Spinal Cord Injury. Detraining. Health.