Abstract
Background and Objective: Body composition changes such as high body fat percentage, muscle weakening and resulting physical problems such as low back pain and weakness in balance and reduced walking speed are among the problems faced by the elderly. Accordingly, the purpose of this study was to investigate the effect of water-based aerobic training on the dynamic balance and walking speed of obese elderly men with low back pain.
Materials and Methods: This research was a semi-experimental study with pre-test and post-test design. The subjects were 36 elderly aged between 60 and 65 years old with low back pain, body fat percentage higher than 35%, waist-hip ratio of over 95% and visceral fat above 100 cm2. In this way, using a systematic non-random sampling technique, the samples were divided into experimental and control groups randomly (each group included 18 subjects). While the control group continued their daily routines, the experimental group performed aerobic exercises for 4 months and three sessions of 60 minutes. All body composition variables were measured using the body composition analysis, walking speed by walking speed test of 10m, and the ability to maintain balance time up and go test before and after the trainings. Independent and paired t-tests were used to analyze the data via SPSS software at the significant level of P < 0.050.
Results It was suggested that experimental group had a significant decrease in the in test time of 10 m walking speed (p = 0.001), time up and go test (p = 0.001), as well as in obesity variables (p = 0.001) and back pain (p = 0.001) after four months; however, no significant reduction was observed in any of the test times and variables of obesity and low back pain in the control group.
Conclusion: aerobic exercise seems to improve walking speed, maintain balance and also reduce obesity and low back pain in obese elderly people and can be used in conjunction with other training programs. However, this research has its own limits and further research is needed.

Key words: Keywords: Elderly, Water-Based Trainings, Abdominal Obesity, Low back pain