Introduction
Spinal cord injury, repetitive muscle contractions, cardiometabolic disease, cord injury, anabolic deficiency, chronic SCI
OXIDATIVE STRESS, AUTONOMIC DYSFUNCTION, SKELETAL MUSCLE ATROPHY, OXIDATIVE STRESS, OSTEOPOROSIS
Individuals with spinal cord injury (SCI) have a distinctive physiology, characterized by a decrease in lean body mass, adipose tissue accumulation, increased risk of osteoporosis, anabolic deficiency, autonomic dysfunction, and cardiometabolic disease [Redox status is a physiological equilibrium in human cells, in which oxidants and antioxidants constantly interact. Oxidative stress is a condition where the body’s antioxidant defense cannot attenuate the damaging effects of free radicals and other reactive oxygen species (ROS). Exercise and repetitive muscle contractions produces “normal” levels of ROS which is essential for normal cellular homeostasis and function. However, overproduction of ROS induced by exhaustive high-intensity exercise, may result in oxidative stress causing cellular damage and skeletal muscle atrophy [Spinal cord injury forces an extreme form of physical inactivity on the denervated muscle, and excessive ROS production is also demonstrated in prolonged periods of skeletal muscle inactivity [Physical activity and exercise is important after SCI to minimize a sedentary lifestyle, promote independent mobility and counteract the negative health issues related to SCI [The aim of this study was to measure biomarkers of oxidative stress and antioxidants, at rest, during and after a single bout of high-intensity arm cranking exercise in persons with chronic SCI (>1 year postinjury). We included a matched able-bodied control group to compare the changes in biomarkers. Our hypothesis was that persons with chronic SCI have a lower redox capacity in response to a HIIT exercise compared to able-bodied individuals.