• Aquatic Exercise;
  • Chronic Low Back Pain;
  • Disability;
  • Quality of Life;
  • Body Composition;
  • Physical Fitness



To study the effects of an aquatic therapy program with different frequencies (2 vs 3 days per week) in chronic low back pain.


Non-randomized comparison trial.


Sport and spa community health club.


Fifty-four adults with chronic low back pain (48.9 ± 10.0 years).


Eight-week aquatic therapy program.

Outcome Measures

Pain (visual analog scale [VAS]), disability (Oswestry Disability Index), and quality of life (Short-Form Health Survey 36), body composition (weight, body mass index, body fat mass, body fat percentage, and skeletal muscle mass), and health-related fitness (sit and reach, handgrip strength, curl-up, Rockport 1-mile test).


Both experimental groups presented significant improvements in low back pain and disability (P < 0.001) compared with control group. The 3 days/week group showed significantly greater benefits at VAS flexion and disability (P < 0.001) than the 2 days/week group. Regarding quality of life, both intervention groups presented significant differences for Physical Role (P < 0.05), Bodily Pain (P < 0.001), General Health (P = 0.012), and Standardized Physical Component (P < 0.001) compared with control group. Both experimental groups significantly improved all health-related fitness parameters (P < 0.01). The 3 days/week group showed significantly greater benefits at curl-up and heart rate (P < 0.001) than the 2 days/week group. No significant changes between treatment groups and control were found in body composition.


Eight weeks of aquatic therapy program decrease levels of back pain and disability, increase quality of life, and improve health-related fitness in adults with chronic low back pain without effects in body composition. A dose–response effect was observed in some parameters, with greater benefits when exercising 3 days per week compared with 2 days.