Objective: To investigate the real-time cardiovascular response to the progressive overload exercise in different levels of spinal cord injury (SCI), and to find out whether regular exercise has effect on these cardiovascular responses.
Methods: The study enrolled 8 able-bodied individuals in the control group plus 15 SCI subjects who were divided into two groups by their neurological level of injury: high-level SCI group (T6 or above) and low-level SCI group (T7 or below). Also, subjects were divided into exercise group and non-exercise group by usual exercise habits. We instructed the subjects to perform exercises using arm ergometer according to the protocol and checked plethysmograph for the real time assessment of blood pressure, heart rate, and cardiac output.
Results: Six subjects were included in high-level SCI group (3 cervical, 3 thoracic injuries), 9 subjects in low-level SCI group (9 thoracic injuries), and 8 able-bodied individuals in control group. During arm ergometer-graded exercise, mean arterial pressure (MAP) was significantly lower in high-level SCI subjects of non-exercise group, compared with high-level SCI subjects of exercise group. In addition, HR was significantly higher in low-level SCI group compared with control group.
Conclusion: There are significant differences in mean arterial pressure of high-level SCI group according to usual exercise habits. We discovered that even in non-athlete high-level SCI, regular exercise can bring cardiac modulation through blood pressure control.
Keywords: Aerobic exercise; Cardiovascular physiological phenomena; Ergometer; Exercise test; Spinal cord injuries.