scholarly journals Reactive hyperemia is not responsible for stimulating muscle protein synthesis following blood flow restriction exercise

2012 ◽  
Vol 112 (9) ◽  
pp. 1520-1528 ◽  
Author(s):  
David M. Gundermann ◽  
Christopher S. Fry ◽  
Jared M. Dickinson ◽  
Dillon K. Walker ◽  
Kyle L. Timmerman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Reactive Hyperemia ◽  
Blood Flow Restriction ◽  
Flow Restriction ◽  
Low Intensity ◽  
Mtorc1 Signaling

Blood flow restriction (BFR) to contracting skeletal muscle during low-intensity resistance exercise training increases muscle strength and size in humans. However, the mechanism(s) underlying these effects are largely unknown. We have previously shown that mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis (MPS) are stimulated following an acute bout of BFR exercise. The purpose of this study was to test the hypothesis that reactive hyperemia is the mechanism responsible for stimulating mTORC1 signaling and MPS following BFR exercise. Six young men (24 ± 2 yr) were used in a randomized crossover study consisting of two exercise trials: low-intensity resistance exercise with BFR (BFR trial) and low-intensity resistance exercise with sodium nitroprusside (SNP), a pharmacological vasodilator infusion into the femoral artery immediately after exercise to simulate the reactive hyperemia response after BFR exercise (SNP trial). Postexercise mixed-muscle fractional synthetic rate from the vastus lateralis increased by 49% in the BFR trial ( P < 0.05) with no change in the SNP trial ( P > 0.05). BFR exercise increased the phosphorylation of mTOR, S6 kinase 1, ribosomal protein S6, ERK1/2, and Mnk1-interacting kinase 1 ( P < 0.05) with no changes in mTORC1 signaling in the SNP trial ( P > 0.05). We conclude that reactive hyperemia is not a primary mechanism for BFR exercise-induced mTORC1 signaling and MPS. Further research is necessary to elucidate the cellular mechanism(s) responsible for the increase in mTOR signaling, MPS, and hypertrophy following acute and chronic BFR exercise.

scholarly journals Blood flow restriction exercise stimulates mTORC1 signaling and muscle protein synthesis in older men

2010 ◽  
Vol 108 (5) ◽  
pp. 1199-1209 ◽  
Author(s):  
Christopher S. Fry ◽  
Erin L. Glynn ◽  
Micah J. Drummond ◽  
Kyle L. Timmerman ◽  
Satoshi Fujita ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Older Men ◽  
Signaling Proteins ◽  
Flow Restriction ◽  
Low Intensity ◽  
Pressure Cuff ◽  
Mtorc1 Signaling

The loss of skeletal muscle mass during aging, sarcopenia, increases the risk for falls and dependence. Resistance exercise (RE) is an effective rehabilitation technique that can improve muscle mass and strength; however, older individuals are resistant to the stimulation of muscle protein synthesis (MPS) with traditional high-intensity RE. Recently, a novel rehabilitation exercise method, low-intensity RE, combined with blood flow restriction (BFR), has been shown to stimulate mammalian target of rapamycin complex 1 (mTORC1) signaling and MPS in young men. We hypothesized that low-intensity RE with BFR would be able to activate mTORC1 signaling and stimulate MPS in older men. We measured MPS and mTORC1-associated signaling proteins in seven older men (age 70 ± 2 yr) before and after exercise. Subjects were studied identically on two occasions: during BFR exercise [bilateral leg extension exercise at 20% of 1-repetition maximum (1-RM) with pressure cuff placed proximally on both thighs and inflated at 200 mmHg] and during exercise without the pressure cuff (Ctrl). MPS and phosphorylation of signaling proteins were determined on successive muscle biopsies by stable isotopic techniques and immunoblotting, respectively. MPS increased 56% from baseline after BFR exercise ( P < 0.05), while no change was observed in the Ctrl group ( P > 0.05). Downstream of mTORC1, ribosomal S6 kinase 1 (S6K1) phosphorylation and ribosomal protein S6 (rpS6) phosphorylation increased only in the BFR group after exercise ( P < 0.05). We conclude that low-intensity RE in combination with BFR enhances mTORC1 signaling and MPS in older men. BFR exercise is a novel intervention that may enhance muscle rehabilitation to counteract sarcopenia.

scholarly journals Effect of Resistance Exercise with Blood Flow Restriction on Muscle Protein Synthesis and mTOR Signaling in Older Men

2009 ◽  
Vol 23 (S1) ◽  
Author(s):  
Christopher S Fry ◽  
Erin L Glynn ◽  
Micah J Drummond ◽  
Kyle L Timmerman ◽  
Satoshi Fujita ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Older Men ◽  
Mtor Signaling ◽  
Blood Flow Restriction ◽  
Flow Restriction

Blood flow restriction during low-intensity resistance exercise increases S6K1 phosphorylation and muscle protein synthesis

2007 ◽  
Vol 103 (3) ◽  
pp. 903-910 ◽  
Author(s):  
Satoshi Fujita ◽  
Takashi Abe ◽  
Micah J. Drummond ◽  
Jerson G. Cadenas ◽  
Hans C. Dreyer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Mtor Signaling ◽  
Blood Flow Restriction ◽  
Signaling Proteins ◽  
Flow Restriction ◽  
Pressure Cuff

Low-intensity resistance exercise training combined with blood flow restriction (REFR) increases muscle size and strength as much as conventional resistance exercise with high loads. However, the cellular mechanism(s) underlying the hypertrophy and strength gains induced by REFR are unknown. We have recently shown that both the mammalian target of rapamycin (mTOR) signaling pathway and muscle protein synthesis (MPS) were stimulated after an acute bout of high-intensity resistance exercise in humans. Therefore, we hypothesized that an acute bout of REFR would enhance mTOR signaling and stimulate MPS. We measured MPS and phosphorylation status of mTOR-associated signaling proteins in six young male subjects. Subjects were studied once during blood flow restriction (REFR, bilateral leg extension exercise at 20% of 1 repetition maximum while a pressure cuff was placed on the proximal end of both thighs and inflated at 200 mmHg) and a second time using the same exercise protocol but without the pressure cuff [control (Ctrl)]. MPS in the vastus lateralis muscle was measured by using stable isotope techniques, and the phosphorylation status of signaling proteins was determined by immunoblotting. Blood lactate, cortisol, and growth hormone were higher following REFR compared with Ctrl ( P < 0.05). Ribosomal S6 kinase 1 (S6K1) phosphorylation, a downstream target of mTOR, increased concurrently with a decreased eukaryotic translation elongation factor 2 (eEF2) phosphorylation and a 46% increase in MPS following REFR ( P < 0.05). MPS and S6K1 phosphorylation were unchanged in the Ctrl group postexercise. We conclude that the activation of the mTOR signaling pathway appears to be an important cellular mechanism that may help explain the enhanced muscle protein synthesis during REFR.

scholarly journals Activation of mTORC1 signaling and protein synthesis in human muscle following blood flow restriction exercise is inhibited by rapamycin

2014 ◽  
Vol 306 (10) ◽  
pp. E1198-E1204 ◽  
Author(s):  
David M. Gundermann ◽  
Dillon K. Walker ◽  
Paul T. Reidy ◽  
Michael S. Borack ◽  
Jared M. Dickinson ◽  
...  
Keyword(s):  
Blood Flow ◽  
Protein Synthesis ◽  
Time Course ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Human Muscle ◽  
Leg Extension ◽  
Or Groups ◽  
Mtorc1 Signaling

Restriction of blood flow to a contracting muscle during low-intensity resistance exercise (BFR exercise) stimulates mTORC1 signaling and protein synthesis in human muscle within 3 h postexercise. However, there is a lack of mechanistic data to provide a direct link between mTORC1 activation and protein synthesis in human skeletal muscle following BFR exercise. Therefore, the primary purpose of this study was to determine whether mTORC1 signaling is necessary for stimulating muscle protein synthesis after BFR exercise. A secondary aim was to describe the 24-h time course response in muscle protein synthesis and breakdown following BFR exercise. Sixteen healthy young men were randomized to one of two groups. Both the control (CON) and rapamycin (RAP) groups completed BFR exercise; however, RAP was administered 16 mg of the mTOR inhibitor rapamycin 1 h prior to BFR exercise. BFR exercise consisted of four sets of leg extension exercise at 20% of 1 RM. Muscle biopsies were collected from the vastus lateralis before exercise and at 3, 6, and 24 h after BFR exercise. Mixed-muscle protein fractional synthetic rate increased by 42% at 3 h postexercise and 69% at 24 h postexercise in CON, whereas this increase was inhibited in the RAP group. Phosphorylation of mTOR (Ser2448) and S6K1 (Thr389) was also increased in CON but inhibited in RAP. Mixed-muscle protein breakdown was not significantly different across time or groups. We conclude that activation of mTORC1 signaling and protein synthesis in human muscle following BFR exercise is inhibited in the presence of rapamycin.

Time course of regional vascular adaptations to low load resistance training with blood flow restriction

2013 ◽  
Vol 115 (3) ◽  
pp. 403-411 ◽  
Author(s):  
Julie E. A. Hunt ◽  
Dermot Galea ◽  
Graham Tufft ◽  
Danny Bunce ◽  
Richard A. Ferguson
Keyword(s):  
Blood Flow ◽  
Resistance Exercise ◽  
Popliteal Artery ◽  
Reactive Hyperemia ◽  
Load Resistance ◽  
T Test ◽  
Blood Flow Restriction ◽  
Flow Restriction ◽  
Low Load ◽  
Transient Improvement

Distortion to hemodynamic and ischemic stimuli during blood flow restriction (BFR) exercise may influence regional vascular adaptation. We examined changes at the conduit, resistance, and capillary level in response to low load resistance exercise with BFR. Eleven males (22 ± 3 yr, 178 ± 4 cm, 78 ± 9 kg) completed 6 wk (3 days/wk) unilateral plantar flexion training with BFR at 30% 1 repetition maximum (1-RM). The contralateral leg acted as a nonexercised control (CON). Popliteal artery function [flow-mediated dilation, FMD%] and structure [maximal diameter] and resistance vessel structure [peak reactive hyperemia] were assessed using Doppler ultrasound before and at 2-wk intervals. Calf filtration capacity was assessed using venous occlusion plethysmography before and after training. BFR training elicited an early increase in peak reactive hyperemia (1,400 ± 278 vs. 1,716 ± 362 ml/min at 0 vs. 2 wk; t-test: P = 0.047), a transient improvement in popliteal FMD% (5.0 ± 2.1, 7.6 ± 2.9, 6.6 ± 2.1, 5.7 ± 1.6% at 0, 2, 4 and 6 wk, respectively; ANOVA: P = 0.002), and an increase in maximum diameter (6.06 ± 0.44 vs. 6.26 ± 0.39 mm at 0 vs. 6 wk; Bonferroni t-test: P = 0.048). Capillary filtration increased after 6 wk BFR training ( P = 0.043). No changes in the CON leg were observed. Adaptation occurred at all levels of the vascular tree in response to low load resistance exercise with BFR. Enhanced peak reactive hyperemia and transient improvement in popliteal artery function occurred before changes in artery structural capacity.

Low-intensity Resistance Exercise with Blood Flow Restriction Does Not Activate Coagulation System in Young Men

2010 ◽  
Vol 42 ◽  
pp. 740
Author(s):  
Haruhiko Madarame ◽  
Miwa Kurano ◽  
Haruhito Takano ◽  
Haruko Iida ◽  
Yoshiaki Sato ◽  
...  
Keyword(s):  
Blood Flow ◽  
Resistance Exercise ◽  
Young Men ◽  
Blood Flow Restriction ◽  
Coagulation System ◽  
Flow Restriction ◽  
Low Intensity

scholarly journals Blood flow restriction - short insight of the method

2019 ◽  
Vol 12 (23) ◽  
pp. 11-15
Author(s):  
Tiberiu Puta ◽  
Alexandra Mihaela Stănilă ◽  
Remus Datcu
Keyword(s):  
Blood Flow ◽  
Resistance Exercise ◽  
High Intensity ◽  
Recovery Process ◽  
Load Resistance ◽  
Blood Flow Restriction ◽  
High Intensity Training ◽  
Flow Restriction ◽  
Low Intensity ◽  
Intensity Training

AbstractIntroduction: The blood flow restriction method is a training method that is based on the partial occlusion of circulation during a workout. This technique combines low-intensity exercise with the occlusion of the bloodstream which produces results similar to high-intensity training.Aim: We aimed to identify the areas in which this method is applicable, its potential benefits and effects, recommendations regarding the rules of use for maximal effects (dosage, intensity, etc.), and also possible contraindications or warnings regarding the use of this method.Methods: We have analyzed a number of 20 articles on this topic from the field literature of the last 10 years, using ”google academic” as a search engine.Results: After this study we concluded that blood flow restriction is a method with wide applicability in the field of sports training, but also in the recovery process; however, it requires attention in choosing the necessary equipment. For healthy individuals, best training adaptations occur when combining low-load blood flow restriction resistance exercise with traditional high-load resistance exercise.Conclusion: Low-intensity resistance exercise with blood flow restriction is as effective as high-intensity training (for strength and muscle mass gains), but only the high-intensity protocol promotes significant hypotensive responses after exercise.

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