Objective: To determine the reliability of peak VO2 testing for individuals with spinal cord injury (SCI) in deep water and on land; and to examine the relationship between these two testing conditions. Design: Reliability study. Setting: Comprehensive rehabilitation center in Baltimore, MD, USA. Participants: 17 participants (13 men, 4 women) with motor complete and incomplete SCI. Participants were randomized into either aquatic or arm cycle ergometer first measurements. Intervention: Pilot study to assess peak VO2. Outcome measures: Peak VO2 measured with metabolic cart in supported deep water with the addition of Aquatrainer® connection, and on land with arm cycle ergometer. Two trials were conducted for each condition with 48 h separating each test. Results: Peak oxygen consumption reliability was statistically significant for both conditions, aquatic (r = 0.93, P < 0.001) and arm cycle ergometry (r = 0.96, P < 0.001). Additionally, aquatic and arm cycle peak VO2 correlation existed (r = 0.72, P < 0.001). For these 17 participants, lower extremity motor score influenced supported, deep water peak VO2, B = 0.57, P < 0.02, whereas age, sex, and weight did not impact deep water or ergometer values. Conclusion: Determining peak VO2 for individuals with SCI is highly reproducible for arm cycle ergometry and in deep water assessment. Additionally, aquatic, deep water peak VO2 testing is valid when compared to arm cycle ergometry. Although the peak VO2 relationship between deep water and arm cycle ergometry is high, variance in the two conditions does exist. Therefore, it is important to assess peak VO2 via the same exercise modality utilized in the treatment intervention.
Keywords: Aquatic test; Exercise test; Reliability; SCI; Validity.