Metabolic Stress and Blood Flow Restriction Training as Interventions for Skeletal Muscle Atrophy following Musculoskeletal Injury

Skeletal muscle loss poses significant health issues to both the general clinical population, but also athletes recovering from musculoskeletal (MSK) injury. Whilst resistance training is known to induce skeletal muscle hypertrophy (SMH), 70% of an individual’s one repetition maximum (1RM) is required to elicit such changes. This is not always feasible for the abovementioned populations due to rheumatic limitations and thus, targeting metabolic stress as a stimulus for skeletal muscle hypertrophy may be more favourable than that of mechanical tension. Blood Flow Restriction (BFR) training occludes venous out-flow, whilst sustaining arterial in-flow to the working muscle resulting in a pooling of anaerobic metabolites. As a result, resistance training loads as low as 20% 1RM are capable of eliciting hypertrophic effects equivalent to training at heavier loads, and this is mediated through both endocrine and intramuscular mechanisms. Safe administration of BFR is paramount, especially when prescribing to post-surgical athletes. As such, the coach or clinician in question must take careful consideration regarding pressure application, rest periods and various patient characteristics such as post-surgical timeframe and overall health status.

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Effects of combined treatment with blood flow restriction and low-current electrical stimulation on muscle hypertrophy in rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.00070.2019 ◽

2019 ◽

Vol 127 (5) ◽

pp. 1288-1296

Author(s):

Madoka Yoshikawa ◽

Takeshi Morifuji ◽

Tomohiro Matsumoto ◽

Noriaki Maeshige ◽

Minoru Tanaka ◽

...

Keyword(s):

Skeletal Muscle ◽

Blood Flow ◽

Electrical Stimulation ◽

Muscle Hypertrophy ◽

Combined Treatment ◽

Blood Flow Restriction ◽

Sectional Area ◽

Cross Sectional ◽

Flow Restriction ◽

Skeletal Muscle Hypertrophy

This study aimed to clarify the effects of a combined treatment comprising blood flow restriction and low-current electrical stimulation on skeletal muscle hypertrophy in rats. Male Wistar rats were divided into control (Cont), blood flow restriction (Bfr), electrical stimulation (Es), or Bfr with Es (Bfr + Es) groups. Pressure cuffs (80 mmHg) were placed around the thighs of Bfr and Bfr + Es rats. Low-current Es was applied to calf muscles in the Es and Bfr + Es rats. In experiment 1, a 1-day treatment regimen (5-min stimulation, followed by 5-min rest) was delivered four times to study the acute effects. In experiment 2, the same treatment regimen was delivered three times/wk for 8 wk. Body weight, muscle mass, changes in maximal isometric contraction, fiber cross-sectional area of the soleus muscle, expression of phosphorylated and total-ERK1/2, phosphorylated-rpS6 Ser235/236, phosphorylated and total Akt, and phosphorylated-rpS6 Ser240/244 were measured. Bfr and Es treatment alone failed to induce muscle hypertrophy and increase the expression of phosphorylated rpS6 Ser240/244. Combined Bfr + Es upregulated muscle mass, increased the fiber cross-sectional area, and increased phosphorylated rpS6 Ser240/244 expression and phosphorylated rpS6 Ser235/236 expression compared with controls. Combined treatment with Bfr and low-current Es can induce muscle hypertrophy via activation of two protein synthesis signaling pathways. This treatment should be introduced for older patients with sarcopenia and others with muscle weakness. NEW & NOTEWORTHY We investigated the acute and chronic effect of low-current electrical stimulation with blood flow restriction on skeletal muscle hypertrophy and the mechanisms controlling the hypertrophic response. Low-current electrical stimulation could not induce skeletal muscle hypertrophy, but a combination treatment did. Blood lactate and growth hormone levels were increased in the early response. Moreover, activation of ERK1/2 and mTOR pathways were observed in both the acute and chronic response, which contribute to muscle hypertrophy.

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The effects of practical vascular blood flow restriction training on skeletal muscle hypertrophy

Journal of the International Society of Sports Nutrition ◽

10.1186/1550-2783-11-s1-p18 ◽

2014 ◽

Vol 11 (Suppl 1) ◽

pp. P18 ◽

Cited By ~ 1

Author(s):

John O'Halloran ◽

Bill Campbell ◽

Nicholas Martinez ◽

Shane O’Connor ◽

Jonathan Fuentes ◽

...

Keyword(s):

Skeletal Muscle ◽

Blood Flow ◽

Muscle Hypertrophy ◽

Blood Flow Restriction ◽

Flow Restriction ◽

Skeletal Muscle Hypertrophy

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Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16244897 ◽

2019 ◽

Vol 16 (24) ◽

pp. 4897 ◽

Cited By ~ 9

Author(s):

Krzysztofik ◽

Wilk ◽

Wojdała ◽

Gołaś

Keyword(s):

Blood Flow ◽

Resistance Training ◽

Muscle Hypertrophy ◽

Data Extraction ◽

Metabolic Stress ◽

Efficient Solutions ◽

Blood Flow Restriction ◽

Mechanical Tension ◽

Flow Restriction ◽

Low Load

Background: Effective hypertrophy-oriented resistance training (RT) should comprise a combination of mechanical tension and metabolic stress. Regarding training variables, the most effective values are widely described in the literature. However, there is still a lack of consensus regarding the efficiency of advanced RT techniques and methods in comparison to traditional approaches. Methods: MEDLINE and SPORTDiscus databases were searched from 1996 to September 2019 for all studies investigating the effects of advanced RT techniques and methods on muscle hypertrophy and training variables. Thirty articles met the inclusion criteria and were consequently included for the quality assessment and data extraction. Results: Concerning the time-efficiency of training, the use of agonist–antagonist, upper–lower body supersets, drop and cluster sets, sarcoplasma stimulating training, employment of fast, but controlled duration of eccentric contractions (~2s), and high-load RT supplemented with low-load RT under blood flow restriction may provide an additional stimulus and an advantage to traditional training protocols. With regard to the higher degree of mechanical tension, the use of accentuated eccentric loading in RT should be considered. Implementation of drop sets, sarcoplasma stimulating training, low-load RT in conjunction with low-load RT under blood flow restriction could provide time-efficient solutions to increased metabolic stress. Conclusions: Due to insufficient evidence, it is difficult to provide specific guidelines for volume, intensity of effort, and frequency of previously mentioned RT techniques and methods. However, well-trained athletes may integrate advanced RT techniques and methods into their routines as an additional stimulus to break through plateaus and to prevent training monotony.

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