Introduction: The cellular mechanisms preventing muscle atrophy after anterior cruciate ligament (ACL) regeneration are not well understood. The aim of present study was to investigate the effect of blood flow restriction (BFR) training on serum levels of some muscle atrophy factors in male athletes after ACL reconstruction surgery.
Materials and methods: Twenty male athletes after ACL reconstruction surgery were selected and randomly divided into two groups of BFR training and control (10 in each group). Subjects in both groups performed resistance training (at intensity of 30 to 70 percentage of 10 repetition maximum, 2- 4 sets) for 12 weeks. Furthermore, subjects in the training group performed BFR training (resistance training combined with putting the pressure cuff in the upper thigh at a pressure of 120-180 mm Hg) during 12 weeks. Blood samples were collected before and 48 hours after the last training session and used for analyzing serum levels of atrogin 1 and muscle RING finger protein 1 (MuRF1). Data analysis was done by analysis of covariance and paired t test, and P<0.05 considered significant.
Results: Twelve weeks of BFR training significantly decreased serum levels of atrogin 1 (P=0.01) and MuRF1 (P=0.035) in the post-test compared to the pre-test. In addition, significant differences were observed between the BFR and control groups for atrogin 1 levels (P=0.047).
Conclusion: The findings showed that BFR training reduces the concentration of major proteins associated with muscle atrophy such as atrogin-1 and MuRF1 and plays an important role in inhibiting atrophy and consequently can increase muscle mass following injury.

Introduction The cellular mechanisms of muscular hypertrophy resulting from Blood Flow Restriction (BFR) training have not been well studied. The aim of the present study was to investigate the effect of BFR on serum levels of proxis-1-alpha (PGC-1α), insulin-like growth factor-1 (IGF-1) and myostatin in male athletes after anterior cruciate ligament surgery.
Materials and Methods: 20 people were selected from the volunteers and randomly divided into 2 groups (10 people in each group) 1. BFR exercise; 2- Control. Subjects in both groups performed resistance training movements in 2 to 4 sets with an intensity of 30 to 70% RM. The subjects in the BFR group performed resistance training movements by closing the pressure cuff in the upper thigh with a pressure of 120 to 180 mm Hg. Data were analyzed using analysis of covariance and paired t-test.
Results: The results showed that 12 weeks of BFR training significantly increased the serum concentration of IGF-1 and significantly decreased the serum levels of myostatin in the post-test compared to the pre-test (P = 0.009). The results also showed that BFR training did not have a significant effect on serum PGC-1α concentration.
Conclusion: Overall, the results showed that BFR training leads to changes in serum levels of myostatin and IGF-1, which is of particular importance compared to traditional resistance training.

Introduction: To the best of our knowledge, no study has been evaluated the effect of a combination of resistance training and electrical muscle stimulation (EMS) on muscle hypertrophy factors in injured athletes. The aim of this study was to investigate the effect of EMS on serum levels of some molecular markers of muscle hypertrophy in male athletes after anterior cruciate ligament surgery (ACL).
Materials and Methods: Twenty male athletes after ACL surgery were selected and randomly divided into two groups: EMS and control (10 subjects in each group) of. Subjects in both groups performed resistance training (at intensity of 30-70 percentage of 10-repetition maximum, 2-4 sets). Whereas, subjects in EMS group performed resistance training with EMS at frequency of 35-70 Hz. Blood samples were collected before and 48 hours after the last training session to measure serum levels of sirtoin-1 (SIRT1), visfatin and nitric oxide (NO).
Results: The finding showed that 12 weeks of EMS significantly increased serum levels of SIRT1 (P < 0.001), visfatin (P = 0.02) and NO (P = 0.01) in post-test compared to the pre-test. The results also revealed that the EMS training significantly increased SIRT1 (P < 0.001) and NO (P = 0.021) levels in comparison with the control group. However, there was no significant difference between two groups in visfatin levels (P > 0.05).
Conclusion: The results suggest that EMS training could possibly be a good alternative to the traditional resistance training to stimulate factors related to muscle protein synthesis.