Background and Objectives: It has been shown that low intensity physical activity rarely increases bone density or renewal. Therefore, the purpose of this study was to investigate effects of four weeks of plyometric training with and without vascular occlusion on serum levels of bone‌ alkaline phosphatase (BALP) and C-terminal telopeptide of type I collagen (CTX), as markers of bone formation and bone degeneration in inactive girls.
          Methods: This was a semi-experimental study with a pretest-posttest design. The study population consisted 36 inactive female students aged 23.84±1.096 years with a mean body mass index of 22.59±0.52 kg/m2 who were randomly divided into a plyometric training group without blood flow restriction, a plyometric training group with blood flow restriction and a control group. The experimental groups performed four weeks of plyometric training (three sessions per week), while the control group did not perform any exercise. Blood samples were obtained 48 hours before the first training session and 48 hours after the last training session. Measurement of BALP and CTX was carried out using commercial enzyme-linked immunosorbent assay kits. Collected data were analyzed using t-test and one-way analysis of variance. All statistical analyses were performed using SPSS software (version 23) and at significance level of ≤ 0.05.
          Results: The level of BALP was significantly higher in the low intensity exercise with blood flow restriction group compared to the control group (P=0.005) and the low intensity exercise group without blood flow restriction (P=0.003). The BALP/CTX ratio, as marker of bone metabolism, increased significantly following low intensity exercise with blood flow restriction compared with the other groups (P<0.05). However, low intensity exercise without blood flow restriction induced no significant change in the studied indices.
          Conclusion: Plyometric training with blood flow restriction could be as effective as high intensity training for improving bone metabolism and turnover, particularly in inactive individuals.