Reliability & Validity Of Aquatic Deep Water Peak VO2 Testing For Individuals With Spinal Cord Injury

Abstract

PURPOSE: To understand the reliability of peak VO2 testing for individuals with spinal cord injury (SCI) in deep water and on land arm cycle ergometer; and to determine the relationship between these two testing conditions. METHODS: Nineteen participants (15 men, 4 women) with SCI enrolled in a pilot study to assess peak VO2 using a Cosmed metabolic cart and tubing connection unit (Aquatrainer): (1) in supported vigorous deep water exercise (aquatic), and (2) on land arm cycle ergometer. Participants randomized into either aquatic or arm cycle ergometer measurements, separated by 48 hours both conditions. Seventeen individuals (13 men and 4 women) completed both testing conditions and two others completed only arm ergometer sessions. RESULTS: Peak oxygen consumption correlated clinically and statistically significantly for both conditions, aquatic (n=17, r=0.93, p<0.001) and arm cycle ergometry (n=19, r=0.95, p< 0.001); and a Pearson correlation between aquatic and arm cycle peak VO2 existed (n=17, r=0.70, p<0.002). We hypothesized a priori lower extremity motor score (LEMS), age, gender, and weight could potentially impact peak VO2 outcomes. For these participants only LEMS influenced supported deep water peak VO2, n=14, B=0.66, p<0.008, and arm cycle ergometer peak VO2, n=16, B=0.54, p<0.025. CONCLUSIONS: Determining peak VO2 for individuals with SCI is highly reproducible for arm cycle ergometry and in supported deep water with the metabolic cart Aquatrainer connection. Additionally, supported deep water peak VO2 testing is reliable (R=0.93) and valid (r=0.70) compared to arm cycle ergometry (gold standard). Clinically it is important to assess peak VO2 after an aquatic intervention using the same conditions as the treatment conditions, and both supported deep water and arm cycle ergometer provide reliable and valid peak VO2 outcomes.