Vo2peak And Stroke Volume Are Enhanced By Interval Hybrid Training In Spinal Cord Injured Individuals.

Abstract

PURPOSE: Spinal Cord Injured (SCI) individuals have limited exercise opportunities compared to the able-bodied population. The aim of this study was to examine physiological effects of aerobic high intensity interval training 4 times 4 minutes from combined arm ergometry and leg functional electrical stimulation (cycle FES) ergometry (hybrid exercise). METHODS: A group of 5 SCI individuals volunteered for hybrid exercise 3 times a week for 8 weeks after a previous control period. RESULTS: The body's ability to utilise oxygen maximally from pre- to post- test between control- and endurance training period during the hybrid protocol increased by 25,3% (P= 0, 012) from 24,50(± 3,12) to 30,09 (± 5,63) mL·kg-1·min-1 and during cycle FES ergometry by 26,2% (P = 0, 009) from 8,26(± 2,15) to 10,16 (± 2,06) mL·kg-1 min-1. Stroke volume of the heart and cardiac output measured during hybrid ergometry also improved significantly (P = 0,009) by 37,5% from 76,18(±10,33) to 104,74 (±18,76) mL·beat-1 from pre- to post- test between control- and endurance training period. Adding a 3% workload (W) from the legs contributed to a ∼24% increase in VO2peak peak probably from reduced pooling of blood in the legs during work. CONCLUSIONS: The present study revealed that aerobic high intensity hybrid interval training significantly improves VO2peak and stroke volume of the heart to the highest mean values for VO2peak ever reported from hybrid training in SCI individuals. The increased stroke volume of the heart in a similar magnitude as VO2peak is a reflexion of structural and functional changes in the cardiovascular system, for the first time documented for this patient group. The high intensity aerobic interval training using functional electrical stimulation along with arm cycling is proved sufficient enough to reverse the most important risk factors for cardiovascular disease in the SCI population.