Intramuscular metabolism during low-intensity resistance exercise with blood flow restriction

J Appl Physiol (1985). 2009 Apr;106(4):1119-24. doi: 10.1152/japplphysiol.90368.2008. Epub 2009 Feb 12.


Although recent studies have reported that low-intensity resistance training with blood flow restriction could stress the muscle effectively and provide rapid muscle hypertrophy and strength gain equivalent to those of high-intensity resistance training, the exact mechanism and its generality have not yet been clarified. We investigated the intramuscular metabolism during low-intensity resistance exercise with blood flow restriction and compared it with that of high-intensity and low-intensity resistance exercises without blood flow restriction using (31)P-magnetic resonance spectroscopy. Twenty-six healthy subjects (22 +/- 4 yr) participated and performed unilateral plantar flexion (30 repetitions/min) for 2 min. Protocols were as follows: low-intensity exercise (L) using a load of 20% of one-repetition maximum (1 RM), L with blood flow restriction (LR), and high-intensity exercise using 65% 1 RM (H). Intramuscular phosphocreatine (PCr) and diprotonated phosphate (H(2)PO(4)(-)) levels and intramuscular pH at rest and during exercise were obtained. We found that the PCr depletion, the H(2)PO(4)(-) increase, and the intramuscular pH decrease during LR were significantly greater than those in L (P < 0.001); however, those in LR were significantly lower than those in H (P < 0.001). The recruitment of fast-twitch fiber evaluated by inorganic phosphate splitting occurred in only 31% of the subjects in LR, compared with 70% in H. In conclusion, the metabolic stress in skeletal muscle during low-intensity resistance exercise was significantly increased by applying blood flow restriction, but did not generally reach that during high-intensity resistance exercise. This new method of resistance training needs to be examined for optimization of the protocol to reach equivalence with high-intensity resistance training.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Hypertrophy
  • Magnetic Resonance Spectroscopy
  • Male
  • Muscle Fibers, Fast-Twitch / physiology
  • Muscle Fibers, Skeletal / physiology
  • Muscle, Skeletal / blood supply*
  • Muscle, Skeletal / metabolism*
  • Muscle, Skeletal / physiology
  • Organ Size / physiology
  • Phosphates / metabolism
  • Phosphocreatine / metabolism
  • Physical Fitness / physiology*
  • Regional Blood Flow / physiology
  • Sex Characteristics
  • Weight Lifting / physiology*
  • Young Adult


  • Phosphates
  • Phosphocreatine