Blood Flow Restriction Training and Betaine Supplementation as a Novel Combined Modality to Augment Skeletal Muscle Adaptation: A Short Review

Abstract

Blood flow restriction (BFR) training and betaine supplementation are emerging training tools with growing evidence, potentially providing a synergistic stimulus to augment skeletal muscle adaptation. Betaine may facilitate stretch-mediated anabolism secondary to BFR-induced extracellularto-intracellular fluid influx, whereby their combination may promote a new, low-barrier avenue for athletes and clinical practitioners to elicit hypertrophy and strength. This review aims to (a) demonstrate existing evidence on BFR-and betaine-mediated skeletal muscle growth, (b) provide rationale for their combination as a superior anabolic stimulus, and (c) advocate for athletes and the elderly as prime demographics for a potentially valuable BFR-betaine synergistic therapy.

Comparison of skeletal muscle ultrastructural changes between normal and blood flow‐restricted resistance exercise: A case report

“…In conjunction with resistance exercise load, BFR is likely to induce mTOR activation through increased membrane tension that is caused by increased resistance to sarcolemma transverse movement by greater extracellular osmotic pressure during muscle contractions (Gehlert et al., 2015; Lin & Liu, 2019). Therein, BFR appears to be a modality that can produce similar benefits to traditional resistance training, whilst doing so under a potentially differential adaptation to structural remodelling that might be related to intramuscular swelling of both the extracellular and intracellular compartments (Loenneke, Abe, et al., 2012; Machek et al., 2020). It is imperative for future research to expand upon these data, using more precise methods, such as TEM, to substantiate our findings in a larger participant population and under different training time frames.…”

Human Serum Betaine and Associated Biomarker Concentrations Following a 14 Day Supplemental Betaine Loading Protocol and during a 28 Day Washout Period: A Pilot Investigation

“…Specifically, participants consumed 3 g twice daily (separated by ~12 h) betaine anhydrous (Vital Pharmaceuticals [VPX] Inc., Weston, FL, USA) for 14 days. This loading regimen was chosen to represent the highest betaine dose administered in the performance literature [ 9 ]. Furthermore, the present supplementation timeframe was selected to ostensibly ensure peak skeletal muscle betaine concentrations, predicated on prior rodent pharmacokinetic data [ 21 ].…”

“…This compound not only facilitates normal methylation and the prevention of HCTL accumulation, but can augment anabolic signaling through mechanisms including increased growth hormone (GH) secretion and subsequently elevated insulin-like growth factor-1 (IGF-1) concentrations, alongside potentiating both upstream and downstream mammalian target of rapamycin complex 1 (mTORC1) signaling [ 1 , 5 ]. Betaine is typically supplemented in doses between 2.5 and 6.0 g per day, usually split between two equivalent doses [ 9 ]. Very little research has detailed the effects of betaine supplementation on performance and body composition; however, it appears that it primarily augments muscular endurance via increasing overall volume in higher (8–15) repetition ranges [ 8 ].…”

“…Notwithstanding the aforementioned methyl metabolism enhancements, several betaine-associated performance benefits may be mediated through its role as an organic osmolyte, stabilizing intracellular protein structures (similar to molecular chaperones) and attenuating osmotic stress after being taken up by the osmoregulated betaine/γ-aminobutyric acid transporter (BGT-1; the predominant betaine channel in humans) [ 5 , 15 , 16 ]. Although this compound classically protects cells from cell shrinkage-mediated apoptosis in hypertonic environments such as the renal medulla, it has been postulated that it may also relieve glycolytic exercise-mediated hypotonic stress, which is characterized by short rest periods and concomitant localized acidosis [ 9 , 15 , 17 , 18 ].…”

“…This approach is especially valuable in exercise science research, producing sufficient statistical power with fewer participants in study designs that are often laborious and limited by resources [ 24 , 25 ]. Nevertheless, the available betaine supplementation literature commonly uses a wash-out period anywhere between one to three weeks, but no previous investigations have determined an appropriate post-supplementation washout timeframe and thus warrants investigation [ 9 ]. The current study therefore aimed to test the hypothesis that a 28 day washout period was sufficient to discernably return serum betaine concentrations and several associated parameters (total body water indices, hematocrit, as well as serum GH, IGF-1, and HCY) to baseline levels following a 14 day supplementation period.…”