Acute changes in antioxidants and oxidative stress to vigorous arm exercise: an intervention trial in persons with spinal cord injury and healthy controls.

STUDY DESIGN: Intervention trial. BACKGROUND: Literature remains unclear on possible health benefits and risks assosciated with high intensity exercise for persons with SCI. Elevated oxidative stress levels might influence their ability to exercise at high intensity. We investigated several biomarkers of oxidative stress and antioxidant defense at rest, during and after vigorous exercise among persons with chronic SCI. SETTING: Sunnaas Rehabilitation Hospital, Norway. METHODS: Six participants (five males) with chronic SCI (AIS A, injury level thoracic 2-8, >1 year postinjury) and six matched able-bodied controls performed two maximal arm-cranking tests, with one-three days in between. During the second exercise test, participants performed three bouts with four minutes arm cranking at high intensity (85-95% of peak heart rate (HRpeak)), before they reached maximal effort. Blood and urine biomarkers for oxidative stress and antioxidant levels were collected at six time points at the day of the second exercise test; baseline, at high intensity exercise, at maximal effort, at five, 30 and 60 min post-exercise, and 24 h post exercise. RESULTS: Participants with SCI had significant lower levels of creatinine (∆16 µmol/L, p = 0.03), α-carotene (∆0.14 nmol/L, p < 0.001) and ß-carotene (∆0.51 nmol/L, p = 0.001) at baseline compared to controls. Urine and blood biomarkers of oxidative stress and antioxidant levels showed similar response to vigorous exercise in the SCI and control group. CONCLUSIONS: SCI participants showed similar changes in redox status during high intensity exercise compared to matched able-bodied. SCI participants had lower levels of exogen antioxidants both before, during and after vigorous exercise.

Exercise intensity during exergaming in wheelchair-dependent persons with SCI.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: It is challenging for persons with SCI, especially those who are wheelchair dependent, to find suitable and motivating aerobic exercise modes. Exergaming might be a good option, since it is relatively cheap and can be played at home, alone or with others. However, it is unknown if exergaming is performed at a sufficient exercise intensity. SETTING: Sunnaas Rehabilitation Hospital, Norway. METHODS: Twenty-two men and two women (n = 24) with chronic SCI (AIS A-C), all wheelchair users, were included during inpatient rehabilitation. All participant performed a maximal graded arm-crank test (pretest), while measuring peak oxygen uptake (VO2peak) and peak heart rate (HRpeak). The day after they had a practice playing session with three different exergames (X-box Kinect, Fruit Ninja; Nintendo Wii, Wii Sports Boxing; VR Oculus Rift, boxing). The following day, participants played each exergame for 15 min. During these 45 min of exergaming, exercise intensity, based on VO2peak and HRpeak from the pretest, was monitored. RESULTS: Approximately 30 of the 45 min of exergaming was performed at moderate or high intensity. Participants exercised on average 24.5 min (95%CI 18.7-30.5) at moderate intensity (>50-80% VO2peak) and 6.6 min (95%CI 2.2-10.8) at high intensity (>80% VO2peak). CONCLUSIONS: The participants were able to exercise at moderate or high intensity during exergaming in a considerable amount of time. Exergaming seems to be suitable for aerobic exercise at an intensity that can provide health benefits in wheelchair-dependent persons with SCI.

Effects of High-Intensity Interval Training After Stroke (The HIIT Stroke Study) on Physical and Cognitive Function: A Multicenter Randomized Controlled Trial.

OBJECTIVE: To assess the effects of high-intensity interval training (HIIT) on physical, mental, and cognitive functioning after stroke. DESIGN: The HIIT Stroke Study was a single-blind, multicenter, parallel-group randomized controlled trial. SETTING: Specialized rehabilitation units at 3 Norwegian hospitals. PARTICIPANTS: Adult stroke survivors (N=70) 3 months to 5 years after a first-ever stroke. Mean age was 57.6±9.2 years and 58.7±9.2 years in the intervention and control groups, respectively. INTERVENTIONS: Participants were randomized to standard care in combination with 4×4 minutes of treadmill HIIT at 85%-95% of peak heart rate or standard care only. OUTCOMES: Outcomes were measured using physical, mental, and cognitive tests and the FIM and Stroke Impact Scale. Linear mixed models were used to analyze differences between groups at posttest and 12-month follow-up. RESULTS: The intervention group showed a significant treatment effect (95% confidence interval [CI]) from baseline to posttest on a 6-minute walk test of 28.3 (CI, 2.80-53.77) meters (P=.030); Berg Balance Scale 1.27 (CI, 0.17-2.28) points (P=.025); and Trail Making Test Part B (TMT-B; -24.16 [CI, -46.35 to -1.98] s, P=.033). The intervention group showed significantly greater improvement on TMT-B at the 12-month follow-up (25.44 [CI, -49.01 to -1.87] s, P=.035). The control group showed significantly greater improvement in total Functional Independence Measure score with a treatment effect of -2.37 (CI, -4.30 to -0.44) points (P=.016) at 12-month follow-up. No significant differences were identified between groups on other outcomes at any time point. CONCLUSIONS: HIIT combined with standard care improved walking distance, balance, and executive function immediately after the intervention compared with standard care only. However, only TMT-B remained significant at the 12-month follow-up.

Changes in cardiorespiratory fitness and activity levels over the first year after discharge in ambulatory persons with recent incomplete spinal cord injury.

STUDY DESIGN: Secondary analysis of a clinical trial. OBJECTIVES: To investigate changes in cardiorespiratory fitness (CRF) and activity level in ambulatory persons with SCI during the first year after discharge from inpatient rehabilitation. SETTING: Sunnaas Rehabilitation Hospital, Nesoddtangen, Norway. METHODS: Thirty persons with incomplete SCI, all community walkers (25 males and 5 females, 18-69 years old) were recruited to a clinical trial of a 12 weeks home-based aerobic exercise program of either high or moderate intensity. During the last week of inpatient rehabilitation (baseline), participants performed a maximal exercise test on a treadmill (peak oxygen uptake; peak VO2) and a 6-min walking test (6MWT). Also, total daily energy expenditure (TDEE) and daily amount of steps were measured continuously during 7 days in the participants' homes. All tests were repeated after 3 and 12 months (post tests). RESULTS: Twenty of the 30 clinical trial participants performed baseline and both posttests and are included in this secondary analysis. We found no statistically significant between-group differences in the time course over the first year of either peak VO2, 6MWT, or physical activity outcomes. Therefore, data from both exercise groups and the control group were merged for secondary analyses, revealing statistically significant increase over time in peak VO2, 6MWT, and TDEE. The increase over time in the average daily steps did not reach statistical significance. CONCLUSIONS: Ambulatory persons with SCI were able to increase their CRF levels over the first year after discharge from inpatient rehabilitation, despite a minimal increase in activity levels.

Effects of moderate- and high-intensity aerobic training program in ambulatory subjects with incomplete spinal cord injury-a randomized controlled trial.

STUDY DESIGN: Randomized controlled trial. OBJECTIVES: To investigate if high-intensity interval training (HIIT) exhibits a higher increase in physical capacity and activity levels compared to moderate-intensity training (MIT) and treatment as usual. SETTING: Sunnaas Rehabilitation Hospital. METHODS: Thirty ambulatory participants with incomplete spinal cord injury (SCI) were recruited at discharge from inpatient rehabilitation. Two intervention groups performed a 12-week individual training program at home by walking or running, depending on their physical ability. The MIT group was instructed to exercise three times a week at 70% of maximal heart rate (HRmax), while the HIIT group was instructed to exercise twice a week at 85-95% of HRmax. The control group received treatment as usual. Pre- and post-tests consisted of maximal exercise testing on a treadmill (peak oxygen uptake (peak VO2)), a 6-min walking test (6MWT), and 7 days of continuously activity monitoring (total daily energy expenditure (TDEE) and daily number of steps). RESULTS: The HIIT, MIT, and control groups showed an increase in peak VO2 from pre- to post-test. However, no between-group difference in physical capacity (peak VO2 and 6MWT) and physical activity levels (TDEE and daily number of steps) were found between these groups. CONCLUSIONS: Performing HIIT did not exhibit a greater increase in physical capacity and activity levels than performing MIT or "treatment as usual" in ambulatory participants with SCI. Further studies are needed to elucidate both short- and long-term effects of HIIT and MIT in this SCI subpopulation.

Intermittent mild negative pressure applied to the lower limb in patients with spinal cord injury and chronic lower limb ulcers: a crossover pilot study.

STUDY DESIGN: Randomized, assessor-blinded crossover pilot study. OBJECTIVES: To explore the use of an intermittent negative pressure (INP) device for home use in addition to standard wound care (SWC) for patients with spinal cord injury (SCI) and chronic leg and foot ulcers before conducting a superiority trial. SETTING: Patient homes and outpatient clinic. METHODS: A 16-week crossover trial on 9 SCI patients (median age: 57 years, interquartile range [IQR] 52-66), with leg ulcers for 52 of weeks (IQR: 12-82) duration. At baseline, patients were allocated to treatment with INP + SWC or SWC alone. After 8 weeks, the ulcers were evaluated. To assess protocol adherence, the patients were then crossed over to the other group and were evaluated again after another 8 weeks. Lower limb INP treatment consisted of an airtight pressure chamber connected to an INP generator (alternating 10 s -40mmHg/7 s atmospheric pressure) used 2 h/day at home. Ulcer healing was assessed using a photographic wound assessment tool (PWAT) and by measuring changes in wound surface area (WSA). RESULTS: Seven of nine recruited patients adhered to a median of 90% (IQR: 80-96) of the prescribed 8-week INP-protocol, and completed the study without side effects. PWAT improvement was observed in 4/4 patients for INP + SWC vs. 2/5 patients for SWC alone (P = 0.13). WSA improved in 3/4 patients allocated to INP + SWC vs. 3/5 patients in SWC alone (P = 0.72). CONCLUSIONS: INP can be used as a home-based treatment for patients with SCI, and its efficacy should be tested in an adequately sized, preferably multicenter randomized trial.

Intermittent negative pressure applied to the lower limb increases foot macrocirculatory and microcirculatory blood flow pulsatility in people with spinal cord injury.

STUDY DESIGN: Experimental prestudy and poststudy. OBJECTIVES: Examine the acute effects of intermittent negative pressure (INP) applied to the lower limb on foot circulation in people with spinal cord injuries (SCIs). SETTING: Vascular laboratory, Oslo University Hospital. METHODS: Twenty-four people with SCI (median age 59 years, range 29-74) were exposed to lower leg INP (-40 mm Hg) using an air-tight pressure chamber connected to an INP generator. The contralateral leg was placed outside the pressure chamber. We continuously measured arterial blood flow velocity (ultrasound Doppler), skin blood flow (laser Doppler), skin temperature of the dorsum of the foot, heart rate (ECG) and systemic blood pressure (Finometer) during 5-min baseline (atmospheric pressure), followed by 10-min INP (alternating 10 s -40 mm Hg and 7 s atmospheric pressure), and 5-min post-INP (atmospheric pressure). Skin blood flow was measured on the foot placed outside the pressure chamber. A mixed effects regression model was applied to estimate the effect of INP on blood flow. To quantify flow fluctuations, we calculated cumulative up-and-down changes in arterial blood flow velocity per minute. RESULTS: Flow fluctuations increased during INP compared to baseline [32.3 cm/s/min (95% CI 26.9 to 37.7) vs. 15.2 cm/s/min (95% CI 9.8 to 20.6), P < 0.001]. Peak blood flow velocity and skin blood flow was reached 2-3 s after the onset of negative pressure and increased 33% (95% CI 16 to 46, P < 0.001) and 11% (95% CI -4.1 to 60, P = 0.14) above baseline, respectively. CONCLUSIONS: INP induced increased foot arterial blood flow fluctuations compared to baseline. SPONSORSHIPS: The Norwegian Research Council provided funding to Otivio (grant: 241589).