ABCbodybuilding - View Single Post - Blood Flow Restriction during Low-Intensity Resistance Exercise Increases S6K1 Phosphorylation and Muscle Protein Synthesis.
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Old 02-24-2008, 06:35 PM
MartinofSweden MartinofSweden is offline
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Default Re: Blood Flow Restriction during Low-Intensity Resistance Exercise Increases S6K1 Phosphorylation and Muscle Protein Synthesis.

This topic has been off for a while so I thought Iīd give it an update. Three very interesting studies have been published recently. One of them shows that itīs not necessary to achieve complete occlusion to get positive effects. Thatīs good news for wimps like me. Another study shows that the weight needs to be low and reps high to achieve desired effect. Heavy resistance training without occlusion is more effective than it is with occlusion. And the third and most interesting shows that there is a cross transfer training effect with vascular occlusion, but the non-occluded body part needs to be stimulated with strength training in order to claim the benefit of the subsequent workout of another bodypart with occlution. That sounded really confusing, I know, but check out these abstracts and read for yourselves:

1.Effects of Strength Training and Vascular Occlusion.
Laurentino G, Ugrinowitsch C, Aihara AY, Fernandes AR, Parcell AC, Ricard M, Tricoli V.
Department of Physical Education, Paulista University, Sao Paulo, Brazil.

The purpose of our study was to determine if vascular occlusion produced an additive effect on muscle hypertrophy and strength performance with high strength training loads. Sixteen physically active men were divided into two groups: high-intensity (HI = 6 RM) and moderate-intensity training (MI = 12 RM). An occlusion cuff was attached to the proximal end of the right thigh, so that blood flow was reduced during the exercise. The left leg served as a control, thus was trained without vascular occlusion. Knee extension 1 RM and quadriceps cross-sectional area (MRI) were evaluated pre- and post-8 weeks of training. We only found a main time effect for both strength gains and quadriceps hypertrophy (p < 0.001). Therefore, we conclude that vascular occlusion in combination with high-intensity strength training does not augment muscle strength or hypertrophy when compared to high-intensity strength training alone.

2.Effect of resistance exercise training combined with relatively low vascular occlusion.
Sumide T, Sakuraba K, Sawaki K, Ohmura H, Tamura Y.
Department of Sports Medicine, School of Health and Sports Science, Juntendo University, Japan.

Previous studies have demonstrated that a low-intensity resistance exercise, combined with vascular occlusion, results in a marked increase in muscular size and strength. We investigated the optimal pressure for reduction of muscle blood flow with resistance exercise to increase the muscular strength and endurance. Twenty-one subjects were randomly divided into four groups by the different application of vascular occlusion pressure at the proximal of thigh: without any pressure (0-pressure group), with a pressure of 50mmHg (50-pressure group), with a pressure of 150mmHg (150-pressure group), and with a pressure of 250mmHg (250-pressure group). The isokinetic muscle strength at angular velocities of 60 and 180 degrees /s, total muscle work, and the cross-sectional knee extensor muscle area were assessed before and after exercise. Exercise was performed three times a week over an 8-week period at an intensity of approximately 20% of one-repetition maximum for straight leg raising and hip joint adduction and maximum force for abduction training. A significant increase in strength at 180 degrees /s was noted after exercise in all subjects who exercised under vascular occlusion. Total muscle work increased significantly in the 50- and 150-pressure groups (P<0.05, P<0.01, respectively). There was no significant increase in cross-sectional knee extensor muscle area in any groups. In conclusion, resistance exercise with relatively low vascular occlusion pressure is potentially useful to increase muscle strength and endurance without discomfort.

3.Cross-Transfer Effects of Resistance Training with Blood Flow Restriction.

BASIC SCIENCES

Medicine & Science in Sports & Exercise. 40(2):258-263, February 2008.
MADARAME, HARUHIKO 1; NEYA, MITSUO 1; OCHI, EISUKE 2; NAKAZATO, KOICHI 2; SATO, YOSHIAKI 3; ISHII, NAOKATA 1
Abstract:
Purpose: This study investigated whether muscle hypertrophy-promoting effects are cross-transferred in resistance training with blood flow restriction, which has been shown to evoke strong endocrine activation.

Methods: Fifteen untrained men were randomly assigned into the occlusive training group (OCC, N = 8) and the normal training group (NOR, N = 7). Both groups performed the same unilateral arm exercise (arm curl) at 50% of one-repetition maximum (1RM) without occlusion (three sets, 10 repetitions). Either the dominant or nondominant arm was randomly chosen to be trained (OCC-T, NOR-T) or to serve as a control (OCC-C, NOR-C). After the arm exercise, OCC performed leg exercise with blood flow restriction (30% of 1RM, three sets, 15-30 repetitions), whereas NOR performed the same leg exercise without occlusion. The training session was performed twice a week for 10 wk. In a separate set of experiments, acute changes in blood hormone concentrations were measured after the same leg exercises with (N = 5) and without (N = 5) occlusion.

Results: Cross-sectional area (CSA) and isometric torque of elbow flexor muscles increased significantly in OCC-T, whereas no significant changes were observed in OCC-C, NOR-T, and NOR-C. CSA and isometric torque of thigh muscles increased significantly in OCC, whereas no significant changes were observed in NOR. Noradrenaline concentration showed a significantly larger increase after leg exercise with occlusion than after exercises without occlusion, though growth hormone and testosterone concentrations did not show significant differences between these two types of exercises.

Conclusion: The results indicate that low-intensity resistance training increases muscular size and strength when combined with resistance exercise with blood flow restriction for other muscle groups. It was suggested that any circulating factor(s) was involved in this remote effect of exercise on muscular size.
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