Objectives: To evaluate the effect size on non-specific chronic low back pain (CLBP) of evidence-based physiotherapy (EBP) with and without the addition of deep water running (DWR) on pain, physical disability and general health state.

Materials and methods: Randomized, double-blind, controlled trial (therapists and assessors) involving 46 persons with CLBP over 15 weeks with two interventions, presented three times a week. Each group received EBP (personalized exercise program, manual therapy and health education) while one group performed supplementary 20 min sessions of DWR at the individualized aerobic threshold. Measurements were made pre and post intervention for pain, disability and general health. Range of motion of lumbar spine in the sagittal plane, maximum isometric strength and muscle endurance of lumbar and hip extensors was assessment.

Inclusion Criteria:

• Participants were diagnosed with non-specific CLBP, with no radiation to the legs, and lasting at least three months

Exclusion Criteria:

• Low back pain as a result of specific spinal disease, infection, tumor, osteoporosis, fracture, structural deformity, inflammatory disorder, radicular syndrome or caudal equine syndrome
• Patients not able to follow instructions
• Patients with any digressive condition