Boosting is the induction of autonomic dysreflexia (AD) to reflexively activate otherwise dormant thoracolumbar sympathetic circuitry to “boost” the capacity of the cardiovascular system and enhance exercise performance. AD is a life-threatening condition unique to individuals with spinal cord injury (SCI) characterized by a sudden increase in sympathetic activity below the level of the SCI. Here we report on the temporal HR response to an episode of unintentional boosting during a validated field-based exercise performance test in an athlete with tetraplegia.
An athlete with SCI (C6 motor-complete, sensory-incomplete) completed a 20 ×20 m repeated sprint field test on two consecutive days. During the 13th sprint on day 2, the athlete unintentionally boosted via bladder overdistension. Average HR when boosted (i.e., sprints 14–20) was considerably higher than before boosting (141 ± 4 vs 116 ± 7 bpm) and compared with corresponding sprints on day 1 (141 ± 4 bpm vs 120 ± 1 bpm). Average time to complete 20 m sprints when boosted was also faster than the corresponding sprints on day 1 (6.70 ± 0.05 s vs 6.87 ± 0.05 s).
This case report highlights the immediate effect of boosting on HR and field-based exercise performance and supports the suggestion that exercise performance in athletes with SCI is limited by cardiovascular capacity.
1School of Kinesiology, University of British Columbia, Vancouver, BC, CANADA;
2International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, CANADA; and
3Canadian Sport Institute-Pacific, Victoria, BC, CANADA
Address for correspondence: Christopher West, Ph.D., ICORD-BSCC, UBC, 818 West 10th Ave, Vancouver, BC, Canada V5Z 1M9; E-mail: firstname.lastname@example.org.
Submitted for publication March 2018.
Accepted for publication July 2018.