Blood flow restriction during the resting periods of high-intensity resistance training does not alter performance but decreases MIR-1 and MIR-133A levels in human skeletal muscle

Figures

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  Fig. 1. The layout of the study. The protocol of the study is summarized in this figure. One week prior to the first BFR exercise, muscle biopsy samples were taken (black arrow). Three days following the biopsy participants conducted a 3RM test (black rectangle), two days afterwards a 70% 1RM test (black circle) was performed. After two days of recovery subjects started the BRF protocol (details in the text). Twenty four hours after the last BFR exercise session muscle biopsy samples were taken, followed by functional tests with similar timing to the pre-workout period. Abbreviations: d. = day, h. = hours.

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  Fig. 2. Changes at the average power during the training period. The average performance of the subjects was measured in every training session during the four week training period. Significant differences were not detected between the groups. However, the average performance significantly increased after 12 training sessions. Mean ​± ​SD, marks: ∗ p ​< ​0.05 vs. initial value in BFR group, # p ​< ​0.05 vs. initial value in C group.

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  Fig. 3. 3 RM and 70% of the 1RM results The three repetition maximum and the 70% 1 RM maximum were measured before and after four weeks of training. C1: result in the control group before the training period, C2: result in control group after the training period, BFR1: result in the occlusion group before the training period, BFR2: result in the occlusion group after the training period. Results are expressed as mean ​± ​SD, n ​= ​9 in each group, ∗p ​< ​0.05 compared to initial values in BFR, p ​< ​0.05 compared to initial values in control group.

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  Fig. 4. miR-1, miR-133a levels and the relationship between miR-1 and miR-133a BFR decreased the levels of miR-1 (A) and miR-133a (B) compared to values of the subjects trained without BFR. A strong correlation was found between miR-1 and miR-133a. C1: result in the control group before the training period, C2: result in the control group after the training period, BFR1: result in the blood flow restriction group before the training period, BFR2: result in the blood flow restriction group after the training period. Results are expressed as mean ​± ​SD, n ​= ​11 in each group, ∗ p ​< ​0.05 compared to initial values.

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  Fig. 5. The levels of miR-206, miR-133b, miR-486, and miR-499 BFR training did not alter the levels of miR-206, miR-133b, miR-486 and miR-499 compared to the training without BFR or the initial data.