Study aim: To evaluate the effects of resistance training and nano-curcumin supplementation on insomnia severity and selected sleep-related biomarkers in 18–25-year-old men with chronic Insomnia Disorder Design: 12-week randomized, placebo-controlled, 2×2 factorial, parallel-group clinical trial; n=80; individual randomization; computer-generated block randomization (block size 4) with sequentially numbered opaque sealed envelopes; double-blind supplementation. Settings and conduct: This study will be conducted at the Health Research Center of islamic azad university shahrekord branch. Participants will be will be randomly allocated with block sizes of four to tree intervention and one control groups. Blinding (using microcrystalline cellulose in control group) will be used to prevent bias. Participants/Inclusion and exclusion criteria: Inclusion criteria: male aged 18–25 years; Petersburg scale more than 5; clinician-confirmed insomnia disorder more than 3 months with daytime impairment. Exclusion criteria: other diagnosed sleep disorders; shift work; usage of sleep drugs in recent 6 months. Intervention groups: Intervention group 1: Resistance training (3 sessions/week for 12 weeks; 17:00–19:00) plus nano-curcumin 40 mg (Exir Nano Sina Company, Iran) twice daily for 12 weeks. Intervention group 2: Resistance training plus placebo (microcrystalline cellulose, Barij Essence Pharmaceutical Company, Kashan, Iran) twice daily for 12 weeks. Intervention group 3: Usage of nano-curcumin for 12 weeks. Control group: Usage of placebo for 12 weeks. Main outcome variables: Insomnia Severity Index total score, Total sleep time, Wake after sleep onset, Sleep efficiency, Urinary 6-sulfatoxymelatonin, Cortisol awakening response, interleukin-6