Comparison of 1- Versus 3-Minute Stage Duration During Arm Ergometry in Individuals With Spinal Cord Injury

OBJECTIVE: To investigate the effect of stage duration on peak physiological response to arm ergometry incremental exercise testing in individuals with spinal cord injury or disease (SCI/D) in support of developing a more individualized approach to testing.

DESIGN: Parallel reliability study.

SETTING: University research laboratory.

PARTICIPANTS: Individuals with SCI/D (N=38) performed 2 peak oxygen consumption assessments comprised of 1-minute or 3-minute stages on 1 day.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Heart rate and oxygen consumption were recorded continuously from baseline through recovery. Every 1 minute or 3 minutes, resistance increased at an individualized level, and participants continued until volitional fatigue. The highest 30-second average was selected as peak oxygen consumption (Vo2peak) and peak heart rate. The highest workload achieved for ≥30 seconds was recorded as peak power output (PO).

RESULTS: Intraclass correlation coefficients (ICCs) were >.95 for the following variables: absolute Vo2peak (mean ± SD, 1min: 1.2±0.7, 3min: 1.2±.62L/min; 95% CI, .91-.98), relative Vo2peak (mean ± SD, 1min: 16.6±9.4, 3min: 15.8±8.0mL/kg/min; 95% CI, .90-.98), absolute peak PO (mean ± SD, 1min: 61±41, 3min: 66±41W; 95% CI, .92-.98), and relative peak PO (mean ± SD, 1min: .80±56, 3min: .90±.55W/kg; 95% CI, .91-.98). There was no significant difference in peak heart rate between 3 minutes (132±27 beats per minute [bpm]) and 1 minute (130±28 bpm); however, the ICC lower limit was <.75 (0.67-0.90). Total test time was significantly longer in the 3-minute (8:17±2:52min:s) than in the 1-minute (6:29±2:21min:s) protocol.

CONCLUSIONS: For measuring peak physiological values in an incremental arm ergometry test, stage duration is of little consequence because similar values were obtained for the main outcome measures in both protocols.