Aquatic, deep water peak VO₂ testing for individuals with spinal cord injury

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.