Effect of Blood Flow Restriction Exercises: Light and Long vs Hard and Short Protocol
【Supercategory：7. DESCENTE SPORTS SCIENCE Subcategory：7.45 Vol.45】
ABSTRACT
Resistance exercise with blood flow restriction （BFR） is a new training method providing significant training effects despite the use of low-intensity mechanical loads. It was previously demonstrated that BFR remarkably enhances muscular metabolic stress in resistance exercise and that the metabolic stress was effectively enhanced by increasing mechanical intensity but not BFR pressure. However, because of blocking the metabolic recovery by BFR, it is possible that even with low intensity, metabolic stress might gradually increase with respect to increased repetitions and reach sufficient level.
Therefore, in this study, the muscular metabolic stress during resistance exercise with BFR between light-long and hard-short protocols, adjusted by totally the same work volume（load × repetitions） were compared. Twelve male university students were recruited and performed unilateral plantarflexion at 30 repetitions/min in a whole body magnetic resonance system. The BFR exercise protocols were as follows: exercise with 10% of one repetition maximum （1-RM） for 360 sec（180 repetitions） , 15% 1-RM for 240 sec（120 repetitions） , 40% 1-RM for 90 sec（45 repetitions） . All protocols were same in total work volume（load × repetitions=1800） . In addition, a standard high-intensity protocol of 65% 1-RM without BFR （60 sec, 30 repetitions） was also performed for comparison. Muscular metabolic stress in the calf muscle, defined as phosphocreatine and intramuscular pH decrease were evaluated by using 31P-magnetic resonance spectroscopy.
Phosphocreatine depletion and intramuscular pH decrease at the end of each exercise were statistically similar and equal to or greater than that in 65% 1-RM without BFR. In conclusion, if the total exercise volume calculated as a product of mechanical load multiplied by repetitions were equal, metabolic stress in exercising muscle might achieve the similar level at the end of exercise with BFR and could provide similar successful training effects.
DECENTE SPORTS SCIENCE Vol.45/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
Resistance exercise with blood flow restriction （BFR） is a new training method providing significant training effects despite the use of low-intensity mechanical loads. It was previously demonstrated that BFR remarkably enhances muscular metabolic stress in resistance exercise and that the metabolic stress was effectively enhanced by increasing mechanical intensity but not BFR pressure. However, because of blocking the metabolic recovery by BFR, it is possible that even with low intensity, metabolic stress might gradually increase with respect to increased repetitions and reach sufficient level.
Therefore, in this study, the muscular metabolic stress during resistance exercise with BFR between light-long and hard-short protocols, adjusted by totally the same work volume（load × repetitions） were compared. Twelve male university students were recruited and performed unilateral plantarflexion at 30 repetitions/min in a whole body magnetic resonance system. The BFR exercise protocols were as follows: exercise with 10% of one repetition maximum （1-RM） for 360 sec（180 repetitions） , 15% 1-RM for 240 sec（120 repetitions） , 40% 1-RM for 90 sec（45 repetitions） . All protocols were same in total work volume（load × repetitions=1800） . In addition, a standard high-intensity protocol of 65% 1-RM without BFR （60 sec, 30 repetitions） was also performed for comparison. Muscular metabolic stress in the calf muscle, defined as phosphocreatine and intramuscular pH decrease were evaluated by using 31P-magnetic resonance spectroscopy.
Phosphocreatine depletion and intramuscular pH decrease at the end of each exercise were statistically similar and equal to or greater than that in 65% 1-RM without BFR. In conclusion, if the total exercise volume calculated as a product of mechanical load multiplied by repetitions were equal, metabolic stress in exercising muscle might achieve the similar level at the end of exercise with BFR and could provide similar successful training effects.
DECENTE SPORTS SCIENCE Vol.45/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
| Researcher | Koichi Okita |
|---|---|
| University or institution | Department of Sport Education,Hokusho University |
Keywords
blood flow restriction, metabolic stress, ischemia, training, muscle hypertrophy