INTRODUCTION

In recent years, a wide range of females, especially young females, have chosen resistance training as their desired sports activity, and this training has become one of the important components of the physical fitness program (1). However, females constitute the highest proportion of consumers of food supplements and according to some reports, 77% of them have used at least one ergogenic substance or food supplement (3). Women who choose to engage in strength training should ensure adequate amounts of essential nutrients in their diet, meaning that their diet should include not only enough amino acids for muscle repair, but also healthy fatty acids for balance, hormonal system, and absorption of fat-soluble vitamins. Nevertheless, oxidative stress leads to changes in iron homeostasis and the reduction of antioxidants (5). In this regard, omega-3 has recently been considered as an ergogenic supplement that may prevent exercise-induced muscle damage by providing a protective effect as an antioxidant (5).

Preliminary evidence in previous studies shows that hormonal responses to training and nutritional interventions (for example, increasing the concentration of growth hormone or the ratio of testosterone to cortisol) are closely related to the improvement of anabolic conditions and changes in skeletal muscle size (9). Therefore, the present study aimed to investigate the effect of resistance training with body weight and omega-3 supplementation on the maximum strength of upper and lower body muscles and the levels of testosterone hormones and salivary cortisol in non-athlete women.

METHODS

This study was performed on 40 healthy females with a mean age of 23.38±3.6 years old. Moreover, their mean weight, height, and body mass index were 59.73 ± 8.27 kg, 135.20 ± 4.92 cm, and 21.91 ± 2.57 kg/m². They were randomly divided into four groups, namely omega-3 supplementation, resistance training and omega-3 supplementation, resistance training only, and control groups. The resistance training program was performed in three sessions a week with an intensity of 55-70% of one maximum repetition for six weeks. Moreover, three 1,000 mg omega-3 capsules were prescribed daily in three meals. The maximum strength of the upper and lower body muscles as well as the levels of testosterone hormones and salivary cortisol before and after the exercise and supplementation protocol were evaluated and the resulting data were analysed by the analysis of variance test.

RESULTS

The results regarding the range of maximum upper body strength changes indicated that the effect of resistance training (P=0.64), omega-3 supplementation (P=0.72), and the interactive effect of exercise and supplementation (P=0.33) were not significant. Moreover, it was observed that the effect of resistance training (P=0.11), the effect of omega-3 supplement (P=0.21), and the interactive effect of exercise and supplement (P=0.43) on the maximum strength of the lower body were not significant. In addition, the results indicated that six weeks of resistance training with body weight and omega-3 supplementation alone and interactively did not have a significant effect on the levels of testosterone (training: P=0.08, supplement: P=0.72, and training+
supplement: P=0.81) and salivary cortisol (training: P=0.44, supplement: P=0.38, and training+
supplement: P=0.31) in young women.

There was no significant change in the levels of testosterone hormones and salivary cortisol in non-athlete females after six weeks of resistance training with body weight and omega-3 supplementation. It seems that this protocol will not be suitable for maximizing anabolic conditions in young women.

Ethical Considerations

Compliance with ethical guidelines

The present study was conducted after obtaining the code of ethics in research under the number IR.QUMS.REC.1402.132. Informed consent was obtained from the participants, confidentiality was maintained and the participants were free to leave the study.

Funding

This study received no funding.

Authors’ Contributions

The authors contributed equally to the conceptualization and writing of the article. All of the authors approved the content of the manuscript and agreed on all aspects of the work.

Conflict of Interest

The authors declared no conflict of interest.

Acknowledgments

The authors would like to thank all those who helped in carrying out this research.