Objective: The aim of this study was to determine the effect of high-intensity interval training during combined arm cycling exercise (ACE) and functional electrical stimulation leg cycling (hybrid exercise), on peak stroke volume and peak oxygen consumption in individuals with spinal cord injury (SCI).
Design: A baseline control trial at an outpatient SCI clinic (St. Olav's University Hospital, Norway) was conducted. Participants included six men with SCI in stable neurologic recovery (ASIA Impairment Scale grade A). The study intervention included aerobic high-intensity hybrid exercise training three times a week for 8 wks preceded by a 7-wk control period of regular daily activity. Main outcome measures were peak stroke volume during hybrid cycling and peak oxygen consumption during hybrid cycling, ACE, and functional electrical stimulation leg cycling. The tests were conducted at three time points: 1, baseline; 2, control; and 3, post-training.
Results: Data are presented as mean (SD). From control to post-training tests, a significant increase in peak stroke volume by 33% (P = 0.004), from 77.7 (9.9) to 103.4 (17.1) ml/beat, was found. Furthermore, between control and post-training tests, hybrid peak oxygen consumption increased by 24.4%, from 24.6 (3.9) to 30.6 (5.2) ml kg−1 min−1 (P = 0.003), and peak oxygen consumption during isolated ACE and functional electrical stimulation cycling increased by 25.9% (P = 0.001) and 23.5% (P = 0.007), respectively.
Conclusions: Training aerobic high-intensity hybrid intervals at 85%-95% of peak Watt was feasible for this group of SCI men and significantly increased peak stroke volume and peak oxygen uptake. Because aerobic capacity is directly linked to mortality and morbidity, the present study may be useful for designing training programs sufficient to reverse the risk of cardiovascular disease in SCI.
From the Dept. of Circulation and Biomedical Imaging (BB, JH, TK, JH) and Dept. of Clinical Neuroscience (GL), Norwegian University of Science and Technology, Faculty of Medicine, Trondheim; Dept. of Physical Medicine and Rehabilitation, St Olav's University Hospital, Trondheim (BB, GL, JH); and Hokksund Medical Rehabilitation Centre, Hokksund, Norway (JH).
All correspondence and requests for reprints should be addressed to: Berit Brurok, MSc, St Olavs University Hospital, Olav Kyrres gt 17 7006, Trondheim, Norway.
Parts of the results from this study have been presented at the International Spinal Cord Society Conference in Durban South Africa, September 1, 2008. This research received funding from St Olav's University Hospital, Sintef Unimed Innovation, and the Norwegian University of Science and Technology, Faculty of Medicine. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.