ECCENTRIC RESISTANCE TRAINING AND BLOOD FLOW RESTRICTION

Zachary Pope1 & Jeffery Willardson2; 1Oklahoma State University, Stillwater, Oklahoma; 2Eastern Illinois University, Charleston, Illinois Research into blood flow restriction (BFR) and resistance exercise has indicated the promising potential for use of this novel training modality in both rehabilitative and performance based settings; however, research into the effects of contraction specificity and blood flow restricted exercise have yet to be examined. PURPOSE: Therefore, the purpose of this study was to investigate the muscular strength and hypertrophic responses following a four week (two sessions per week) training intervention involving resistance exercise utilizing only eccentric muscle contractions with or without blood flow restriction. METHODS: Eighteen young, male, recreational weightlifters were recruited to participate in this study. Prior to the training intervention subjects attended three sessions. The first session was to obtain demographic information (age, height, body mass) and familiarize each of the participants with the testing and training equipment. After the familiarization session, two sessions (separated by 7 days) were performed to obtain each participants’ pre-training values for muscular strength assessed via elbow flexion one repetition maximum (1-RM). Additionally, upper-arm muscle cross-sectional area (CSA) was assessed during each of these sessions using an estimation equation derived from the circumference and skinfolds. Subjects were then randomized into three training conditions, eccentric resistance training only (ECC), eccentric resistance training with BFR (OCC), and a control training group (CON). Following each intervention, participants strength and CSA were reassessed and compared to pre-training values. RESULTS: Following training, results indicated no significant difference between (P \u3e 0.05) or within groups (P \u3e 0.05) for 1-RM elbow flexion strength. Regarding upper-arm CSA, there was a significant main effect for time (between pre- and post-training) when collapsed across groups (P = 0.01); however, there was no significant group x time interaction (P \u3e 0.05). CONCLUSION: The findings of the current study indicate that the addition of BFR to eccentric resistance exercise does not provide superior muscle strength nor size adaptations compared to eccentric resistance training without BFR or regular resistance training. Further research may resolve issues with contraction specificity with regards to blood flow restriction resistance training