Low-intensity exercise can increase muscle mass and strength proportionally to enhanced metabolic stress under ischemic conditions

Skeletal muscle bulk and strength are becoming important therapeutic targets in medicine. To increase muscle mass, however, intensive, long-term mechanical stress must be applied to the muscles, and such stress is often accompanied by orthopedic and cardiovascular problems. We examined the effects of circulatory occlusion in resistance training combined with a very low-intensity mechanical load on enhancing muscular metabolic stress and thereby increasing muscle bulk. Muscular metabolic stress, as indicated by the increases in inorganic phosphate (Pi) and a decrease in intramuscular pH, was evaluated by 31P-magnetic resonance spectroscopy during unilateral plantar-flexion at 20% of the one-repetition maximum (1-RM) with circulatory occlusion for 2 min in 14 healthy, male untrained participants (22 yr) at baseline. Participants performed two sets of the same exercise with a 30-s rest between sets, 2 times/day, 3 days/wk, for 4 wk. The muscle cross-sectional area (MCA) of the plantar-flexors and the 1-RM were measured at baseline and after 2 and 4 wk of training. MCA and 1-RM were significantly increased after 2 and 4 wk ( P < 0.05, respectively). The increase in MCA at 2 wk was significantly ( P < 0.05) correlated with the changes in Pi ( r = 0.876) and intramuscular pH ( r = 0.601). Furthermore, the increases in MCA at 4 wk and 1-RM at 2 wk were also correlated with the metabolic stress. Thus enhanced metabolic stress in exercising muscle is a key mechanism for favorable effects by resistance training. Low-intensity resistance exercise provides successful outcomes when performed with circulatory occlusion, even with a short training period.

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

Journal of Applied Physiology ◽

10.1152/japplphysiol.90368.2008 ◽

2009 ◽

Vol 106 (4) ◽

pp. 1119-1124 ◽

Cited By ~ 83

Author(s):

Tadashi Suga ◽

Koichi Okita ◽

Noriteru Morita ◽

Takashi Yokota ◽

Kagami Hirabayashi ◽

...

Keyword(s):

Blood Flow ◽

Resistance Training ◽

Resistance Exercise ◽

High Intensity ◽

Plantar Flexion ◽

Blood Flow Restriction ◽

Resonance Spectroscopy ◽

Flow Restriction ◽

Low Intensity ◽

Intramuscular Ph

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 31P-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 (H2PO4−) levels and intramuscular pH at rest and during exercise were obtained. We found that the PCr depletion, the H2PO4− 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.

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Muscle metabolism during exercise in young and older untrained and endurance-trained men

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.5.2125 ◽

1993 ◽

Vol 75 (5) ◽

pp. 2125-2133 ◽

Cited By ~ 104

Author(s):

A. R. Coggan ◽

A. M. Abduljalil ◽

S. C. Swanson ◽

M. S. Earle ◽

J. W. Farris ◽

...

Keyword(s):

Magnetic Resonance ◽

Muscle Mass ◽

Citrate Synthase ◽

Metabolic Response ◽

Plantar Flexion ◽

Muscle Metabolism ◽

Resonance Spectroscopy ◽

Age Related ◽

Rate Of Increase ◽

Response To Exercise

To examine effects of aging and endurance training on human muscle metabolism during exercise, 31P magnetic resonance spectroscopy was used to study the metabolic response to exercise in young (21–33 yr) and older (58–68 yr) untrained and endurance-trained men (n = 6/group). Subjects performed graded plantar flexion exercise with the right leg, with metabolic responses measured using a 31P surface coil placed over the lateral head of the gastrocnemius muscle. Muscle biopsy samples were also obtained for determination of citrate synthase activity. Rate of increase in P(i)-to-phosphocreatine ratio with increasing power output was greater (P < 0.01) in older untrained [0.058 +/- 0.022 (SD) W-1] and trained men (0.042 +/- 0.010 W-1) than in young untrained (0.038 +/- 0.017 W-1) and trained men (0.024 +/- 0.010 W-1). Plantar flexor muscle cross-sectional area and volume (determined using 1H magnetic resonance imaging) were 11–12% (P < 0.05) and 16–18% (P < 0.01) smaller, respectively, in older men. When corrected for this difference in muscle mass, age-related differences in metabolic response to exercise were reduced by approximately 50% but remained significant (P < 0.05). Citrate synthase activity was approximately 20% lower (P < 0.001) in older untrained and trained men than in corresponding young groups and was inversely related to P(i)-phosphocreatine slope (r = -0.63, P < 0.001). Age-related reductions in exercise capacity were associated with an altered muscle metabolic response to exercise, which appeared to be due to smaller muscle mass and lower muscle respiratory capacity of older subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

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Free leucine supplementation during an 8-week resistance training program does not increase muscle mass and strength in untrained young adult subjects

Amino Acids ◽

10.1007/s00726-017-2427-0 ◽

2017 ◽

Vol 49 (7) ◽

pp. 1255-1262 ◽

Cited By ~ 7

Author(s):

Andreo Fernando Aguiar ◽

Alan Pablo Grala ◽

Rubens Alexandre da Silva ◽

Lúcio Flávio Soares-Caldeira ◽

Francis Lopes Pacagnelli ◽

...

Keyword(s):

Young Adult ◽

Resistance Training ◽

Training Program ◽

Muscle Mass ◽

Leucine Supplementation ◽

Resistance Training Program ◽

Increase Muscle Mass

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Normalized metabolic stress for31P-MR spectroscopy studies of human skeletal muscle: MVC vs. muscle volume

Journal of Applied Physiology ◽

10.1152/jappl.1997.83.3.875 ◽

1997 ◽

Vol 83 (3) ◽

pp. 875-883 ◽

Cited By ~ 20

Author(s):

M. D. Fowler ◽

T. W. Ryschon ◽

R. E. Wysong ◽

C. A. Combs ◽

R. S. Balaban

Keyword(s):

Skeletal Muscle ◽

Power Output ◽

Mr Spectroscopy ◽

Human Skeletal Muscle ◽

Plantar Flexion ◽

Metabolic Stress ◽

Muscle Volume ◽

Resonance Spectroscopy ◽

Plantar Flexor ◽

Spectroscopy Studies

Fowler, M. D., T. W. Ryschon, R. E. Wysong, C. A. Combs, and R. S. Balaban. Normalized metabolic stress for31P-MR spectroscopy studies of human skeletal muscle: MVC vs. muscle volume. J. Appl. Physiol. 83(3): 875–883, 1997.—A critical requirement of submaximal exercise tests is the comparability of workload and associated metabolic stress between subjects. In this study, 31P-magnetic resonance spectroscopy was used to estimate metabolic strain in the soleus muscle during dynamic, submaximal plantar flexion in which target torque was 10 and 15% of a maximal voluntary contraction (MVC). In 10 healthy, normally active adults, (PCr + Pi)/PCr, where PCr is phosphocreatine, was highly correlated with power output normalized to the volume of muscle in the plantar flexor compartment ( r = 0.89, P < 0.001). The same variable was also correlated, although less strongly ( r = 0.78, P < 0.001), with power normalized to plantar flexor cross-sectional area. These findings suggest that comparable levels of metabolic strain can be obtained in subjects of different size when the power output, or stress, for dynamic plantar flexion is selected as a function of plantar flexor muscle volume. In contrast, selecting power output as a function of MVC resulted in a positive linear relationship between (PCr + Pi)/PCr and the torque produced, indicating that metabolic strain was increasing rather than achieving constancy as a function of MVC. These findings provide new insight into the design of dynamic muscle contraction protocols aimed at detecting metabolic differences between subjects of different body size but having similar blood flow capacity and mitochondrial volume per unit of muscle.

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Comparison of Hamstrings and Quadriceps Femoris Muscle Thickness Increment between Agonist-Antagonist Paired Set and Traditional Set Resistance Training in Untrained Healthy Subjects

Surabaya Physical Medicine and Rehabilitation Journal ◽

10.20473/spmrj.v3i2.20976 ◽

2021 ◽

Vol 3 (2) ◽

pp. 60

Author(s):

Gutama Arya Pringga ◽

R. A. Meisy Andriana ◽

Indrayuni Lukitra Wardhani ◽

Lydia Arfianti

Keyword(s):

Resistance Training ◽

Muscle Mass ◽

Muscle Thickness ◽

Quadriceps Femoris ◽

Quadriceps Femoris Muscle ◽

Leg Extension ◽

Increase Muscle Mass ◽

Group 3 ◽

Femoris Muscle ◽

Group 1

Background: Resistance training is an effective way to increase muscle mass. Resistance training with agonist-antagonist paired set method can be an alternative to increase muscle mass within a relatively short training time.Aim: To compare the increase in hamstrings and quadriceps femoris muscle thickness between agonist-antagonist paired set (APS) and traditional set (TS) resistance training in untrained healthy subjects.Material and Methods: This study was an experimental study on 16 untrained healthy men which were randomly assigned to the APS and the TS group. Each group got leg curl and leg extension exercises with equal training volume for 6 weeks. For the APS group, 1 set of leg curls was followed by 1 set of leg extensions, repeated for 3 sets. For the TS group, 3 sets of leg curls were followed by 3 sets of leg extensions. Muscle thickness was compared from pre- to post-training and between the intervention groups using B-mode ultrasound.Results: Muscle thickness of the hamstrings and quadriceps femoris increased significantly from pre- to post-training in both groups (p<0.05). The increase in muscle thickness between the two groups was not significantly different (p> 0.05).Conclusion: Resistance training with the APS method did not give a higher increment of hamstrings and quadriceps femoris muscle thickness compared to the TS method in healthy untrained subjects.

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The effects of resistance training with blood flow restriction on muscle strength, muscle hypertrophy and functionality in patients with osteoarthritis and rheumatoid arthritis: A systematic review with meta-analysis

PLoS ONE ◽

10.1371/journal.pone.0259574 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0259574

Author(s):

Leonardo Peterson dos Santos ◽

Rafaela Cavalheiro do Espírito Santo ◽

Thiago Rozales Ramis ◽

Juliana Katarina Schoer Portes ◽

Rafael Mendonça da Silva Chakr ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Systematic Review ◽

Blood Flow ◽

Resistance Training ◽

Muscle Strength ◽

Muscle Mass ◽

Meta Analysis ◽

Blood Flow Restriction ◽

Flow Restriction ◽

Low Intensity

Introduction Rheumatoid arthritis(RA) and osteoarthritis(OA) patients showed systemic manifestations that may lead to a reduction in muscle strength, muscle mass and, consequently, to a reduction in functionality. On the other hand, moderate intensity resistance training(MIRT) and high intensity resistance training(HIRT) are able to improve muscle strength and muscle mass in RA and OA without affecting the disease course. However, due to the articular manifestations caused by these diseases, these patients may present intolerance to MIRT or HIRT. Thus, the low intensity resistance training combined with blood flow restriction(LIRTBFR) may be a new training strategy for these populations. Objective To perform a systematic review with meta-analysis to verify the effects of LIRTBFR on muscle strength, muscle mass and functionality in RA and OA patients. Materials and methods A systematic review with meta-analysis of randomized clinical trials(RCTs), published in English, between 1957–2021, was conducted using MEDLINE(PubMed), Embase and Cochrane Library. The methodological quality was assessed using Physiotherapy Evidence Database scale. The risk of bias was assessed using RoB2.0. Mean difference(MD) or standardized mean difference(SMD) and 95% confidence intervals(CI) were pooled using a random-effects model. A P<0.05 was considered statistically significant. Results Five RCTs were included. We found no significant differences in the effects between LIRTBFR, MIRT and HIRT on muscle strength, which was assessed by tests of quadriceps strength(SMD = -0.01[-0.57, 0.54], P = 0.96; I² = 58%) and functionality measured by tests with patterns similar to walking(SMD = -0.04[-0.39, 0.31], P = 0.82; I² = 0%). Compared to HIRT, muscle mass gain after LIRTBFR was reported to be similar. When comparing LIRTBFR with low intensity resistance training without blood flow restriction(LIRT), the effect LIRTBFR was reported to be higher on muscle strength, which was evaluated by the knee extension test. Conclusion LIRTBFR appears to be a promising strategy for gains in muscle strength, muscle mass and functionality in a predominant sample of RA and OA women.

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Abstract 14927: Effects of Low Intensity Resistance Exercise Under Kaatsu Condition on Skeletal Muscle Size and Its Safety inCardiovascular Surgery Patients

Circulation ◽

10.1161/circ.142.suppl_3.14927 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

ogawa hironaga ◽

IKUKO SHIBASAKI ◽

Hirotsugu Fukuda ◽

Shigeru Toyoda ◽

Azusa Uematsu ◽

...

Keyword(s):

Skeletal Muscle ◽

Resistance Training ◽

Muscle Strength ◽

Cardiac Rehabilitation ◽

Muscle Mass ◽

Cardiovascular Surgery ◽

Muscle Blood Flow ◽

Leg Extension ◽

Low Intensity ◽

Hemodynamic Deterioration

Introduction: Surgery for cardiovascular disease is often accompanied by sarcopenia and physical frailty, and improvement of muscle mass, muscle strength, and ADL, is often difficult only with cardiac rehabilitation using aerobic exercise. The resistance training under moderately restricted muscle blood flow, named as KAATSU, induces muscle hypertrophy and strengthens muscle through low intensity exercise. However, it remains uninvestigated whether KAATSU resistance training using low intensity load (KAATSU-RE) increases muscle strength, and induces hypertrophy in patients early after cardiovascular surgery. Hypothesis: To investigate the effects of KAATSU-RE on skeletal muscle strength, hypertrophy and its safety in patients early after cardiovascular surgery. Methods: Nine patients early after cardiac surgery were included in this study (seven males, age 54 ± 18 years, BMI 23.0 ± 3.7 kg/m 2 , AVR 5 cases, MVP 3, Bentall operation 1). The patients performed leg extension exercise (20~30% 1RM) under KAATSU condition two times/week for three months. Training started after 200 m walking early after the operation. Skeletal muscle mass index (SMI) was evaluated using bioelectrical impedance analysis (BIA). The anterior mid-thigh thickness (MTH) was measured using B mode transverse ultrasound images. Physical functions (isometric knee extension peak torque, handgrip strength, and walking speed) were also measured at three points, i.e. baseline (before operation), ~7 days early after operation, and ~3 months after the training. Results: SMI and MTH decreased significantly from 7 ± 1.1, and 2.5 ± 0.4 cm preoperatively to 6.7 ± 1.0, and 2.2 ± 0.3 cm approximately 1 week after surgery. Approximately 3 months after the training, they increased significantly to 7.6 ± 0.8 and 3 ± 0.4 cm. During the rehabilitation period, hemodynamic deterioration and side effects including subcutaneous hemorrhage were not observed, and all the patients completely finished the study. Conclusions: These results suggest that KAATSU training safely increased muscle mass in patients in the early perioperative period of cardiovascular surgery. KAATSU training appears to be a promising and effective method for cardiac rehabilitation in patients with cardiovascular surgery.

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