Objective: The purpose of this study was to compare a specific graded exercise test using deep-water running (DWR) with a cycle ergometry (CE) test on land to develop an equation to estimate aerobic threshold for training in DWR in patients with chronic nonspecific low back pain.
Design: This is a cross-sectional study of 23 subjects with chronic nonspecific low back pain. Maximal and submaximal heart rates (HR), blood lactate, and rating of perceived exertion in the aquatic and land-based graded exercise tests were investigated.
Results: The results suggest that both tests were undertaken at maximal intensity. DWR maximal HR was lower (-12%) than that in the CE test. For both tests, the maximal rating of perceived exertion was greater than 18, and maximum blood lactate was 8 mmol/l, with no significant difference between the CE and DWR tests. The lineal regression for estimate aerobic threshold for training in DWR in persons with chronic nonspecific low back pain was as follows: maximal HR DWR = 136.9 + (age × -0.544) + (maximal HR CE + 0.285). The correlation between maximal HR during DWT and CE tests was 0.538 (P = 0.008).
Conclusions: A graded DWR test can be used as an alternative in the assessment of aerobic fitness in chronic nonspecific low back pain.