Background and purpose: non-specific chronic back pain is one of the factors of disability in people. Therefore, the aim of this study is to investigate the effect of eight weeks of resistance training on pain, flexibility and performance of nurses with non-specific chronic back pain.

Method: The present study is part of semi-experimental research. The statistical population included all male nurses suffering from non-specific chronic back pain in Tehran. The sample size of 20 male nurses was divided into two experimental (10) and control (10) groups. The experimental group did resistance exercises for 8 weeks and 4 days a week for 60 minutes in each session, and during this time the control group did their usual life activities. In order to measure the pre-test and post-test, to assess the amount of pain from the visual analog scale and to evaluate the flexibility and performance of the nurses, the tests of trunk bending forward and Esosterian disability were used, respectively. The data has been analyzed using covariance analysis, t-correlation test using SPSS version 23 software at a significant level (p ≤ 0.05).

Findings: The results of data analysis showed that resistance exercises reduced pain, flexibility and performance in the experimental group compared to the pre-test and the control group. Also, a significant difference was observed between the resistance training group and the control group in the post-test (p ≤ 0.05). Also, there was a significant difference between pre-test and post-test in the training group regarding pain, flexibility and performance, but there was no significant difference between pre-test and post-test in the control group (p>0.05).

Conclusion: The results showed the effect of resistance exercises on improving pain, flexibility and performance of nurses with non-specific chronic back pain.