Catecholamines response of high performance wheelchair athletes at rest and during exercise with autonomic dysreflexia.

Autonomic dysreflexia presents a special situation in high-lesion spinal cord injury, however, intentionally or self-induced autonomic dysreflexia directly before or during competition to increase performance, so called 'boosting', is also being reported. In order to examine the influence of autonomic dysreflexia on plasma catecholamines, cardiocirculatory and metabolic parameters, 6 spinal cord injured wheelchair athletes with high-level lesions underwent wheelchair ergometry without (ST1) and with (ST2) autonomic dysreflexia. At the point of exhaustion significantly higher values for norepinephrine and epinephrine were observed in ST2 than in ST1. During autonomic dysreflexia a significantly higher peak performance (77.5 vs. 72.5 watt), higher peak heart rate (161 vs. 149 x min(-1)), and peak oxygen consumption (1.96 vs. 1.85 l x min(-1)), with comparable peak lactate (7.11 vs. 7.00 mmol x l(-1)) were reached on average. The blood pressure values in ST2 were partially hypertensive and higher than in ST1. In conclusion, autonomic dysreflexia, as a sympathetic spinal reflex, leads to a higher release of catecholamines during exercise. This results in higher peak performance, peak heart rate, peak oxygen consumption, and higher blood pressure values. The peak lactate, as an indicator of the anaerobic lactate metabolism, was unchanged. However, autonomic dysreflexia presents an unpredictable risk, caused predominantly by hypertensive blood pressure values, for high-lesion spinal cord injured persons at rest and more so during exercise; it is seen as a prohibited manipulation by the doping guidelines of the International Paralympic Committee.