Recovery Off-Kinetics Following Exhaustive Upper Body Exercise in Spinal Cord Injury.
- 2020
Available in print through MWHC library: 1999 - Winter 2007
Background: People with spinal cord injury (SCI) present with impaired autonomic control when the lesion is above T6. This could lead to delayed cardiorespiratory recovery following vigorous physical activity. Conclusion: A reduced Ktoff during recovery may suggest inefficiencies in replenishing muscle ATP stores and lactate clearance in these participants with SCI. These findings may contribute to the observed lower cardiorespiratory fitness and greater fatigability typically reported in individuals with SCI. Copyright (c) 2020 American Spinal Injury Association. Methods: Participants were 19 individuals with SCI who presented with the inability to voluntarily lift their legs against gravity (age, 44.6 +/- 14.2 years; AIS A, n = 5; AIS B, n = 7; AIS C, n = 7; paraplegia, n = 14; tetraplegia, n = 5) and 10 healthy comparisons (COM; age, 30.5 +/- 5.3 years). All participants performed an arm ergometer cardiopulmonary exercise test (aCPET) to volitional exhaustion followed by a 10-minute passive recovery. O2 uptake (Vo2 ) and CO2 output (Vco2 ) off-kinetics was examined using a mono-exponential model in which tau off (tauoff ) and mean response time (MRT) were determined. The off-kinetics transition constant (Ktoff ) was calculated as DELTAVo2 /MRT. Student t tests were used to compare SCI versus COM group means. Objectives: To characterize and compare gas exchange off-kinetics following exhaustive exercise in individuals with SCI and an apparently healthy control group. Results: COM had a significantly higher relative peak Vo2 compared to SCI (1.70 +/- 0.55 L/min vs 1.19 +/- 0.51 L/min, p = .019). No difference was observed for tauoff between the groups, however Ktoff for both Vo2 and Vco2 was significantly lower in the SCI compared to the COM group.