Strength Training with Blood Flow Restriction Diminishes Myostatin Gene Expression

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Background

Laurentino et al., 2011 set out to investigate growth and differentiation factor-8, also known as myostatin, which is responsible for the regulation of muscle mass. Previous literature has described that an overexpression of myostatin can be associated with reduced muscle mass. With this understanding, investigationat The University of Sáo Paulo focused on the effects of strength and hypertrophy when either,low intensity paired with blood flow restriction or high intensity exercise was performed. Specificallyevaluating the varying responses of myostatin during these strength-training protocols.  These results can present a greater understanding into the manipulation of this physiological response.

Description of Work

Data collection and analysis was conducted on 21 active male participants, which were assigned to one of three groups. 10 participants were assigned to the low intensity (20% 1RM)resistance exercise group (LI), the low intensity with moderate blood flow restriction (LIR) contained 10 individuals and the remaining nine in the high intensity (80% 1RM) group (HI). The individualsparticipated in an eight-week training protocol, beginning with three sets and then progressing to four sets for the remaining four weeks.

Pre and posttest assessments were conducted on maximal dynamic knee extension strength, cross sectional area of the quadriceps, in addition to myostatin, follistatin-like related genes, activitinIIb, growth and differentiation factor-associated serum protein 1, and MAD-related protein mRNA gene expression. For blood flow restriction, a standard blood pressure cuff was used for complete vascular restriction and 80% of that pressure was used for resistance training. After completing the training protocol, the analysis showed increases in cross sectional area in the LIR and HI groups, a decrease in myostatinmRNA expression in the LIR and HI groups, as well as a increase in growth and differentiation factor-associated serum protein 1 and MAD-related protein.

Interpretation/Evaluation

The researcher’s exhibited doctoral level ability to introduce and organize collected data in order for the reader to understand and interpret. Including this elevated level of organization, introductory information was efficient in conveying the main theoretical concept and its association with hypothesis of the study. Each section of the research was thorough in its description and provided the standardization of each protocol, allowing for precise reproducibility of the experiment.

The standardizing of each component allowed for valid pre and post-test assessments for all individuals when conducted by multiple examiners. Utilization of advanced methods and machinery allowed for precise measurements and appropriate blood flow restriction for each participant. By dividing participants into three differing groups enhanced between group analysis to exemplify significant differences.

The inclusion of blood flow restriction at low intensity exercise proved efficacious in increasing both performance and physiological components, similar to high intensity training. For cross sectional area, significant increases were apparent in both the LIR and HI groups when compared to the control group (LI group). When evaluating myostatin, the LIR and HI groups presented significant decreases in this inhibitory factor.

The aim of this study to investigate strength and hypertrophy responses, with respect to myostatin has become a controversial and popular topic among researchers. These designed trials present a furthered understanding of this physiological response for researchers and practitioners alike. In combination with extensive background information, appropriate manipulation of this training variable within exercise prescription, may enhance adaptations for performance and aesthetic athletes.

 🔍 Strength Training with Blood Flow Restriction Diminishes Myostatin Gene Expression. GILBERTO CANDIDO LAURENTINO, CARLOS UGRINOWITSCH, HAMILTON ROSCHEL,MARCELO SALDANHA AOKI, ANTONIO GARCIA SOARES, MANOEL NEVES JR, ANDRE ́ YUI AIHARA, ARTUR DA ROCHA CORREA FERNANDES, and VALMOR TRICOLI. 0195-9131/12/4403-0406/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE. DOI: 10.1249/MSS.0b013e318233b4bc

Zak BrennanComment