Acute physiological responses to combined blood flow restriction and low-level laser.
Eur J Appl Physiol
; 120(6): 1437-1447, 2020 Jun.
Article
em En
| MEDLINE
| ID: mdl-32318813
ABSTRACT
PURPOSE:
Blood flow restriction (BFR) is an innovation in fitness to train muscles with low loads at low oxygen levels. Low-level laser therapy (LLLT) is a bio-energetic approach to alleviate muscle fatigue during resistance training. This study investigated the immediate effect of LLLT pre-conditioning on BFR that accelerates muscle fatigue due to ischemia.METHODS:
Fifteen young adults participated in this study of a crossover randomized design. They completed a low-load contraction with various pre-conditioning (blood flow restriction with low-level laser therapy (LLLT + BFR), blood flow restriction with sham low-level laser therapy (BFR), and control). Force fluctuation dynamics, muscle oxygen saturation of hemoglobin and myoglobin (SmO2), and discharge patterns of motor units (MU) were compared.RESULTS:
Normalized SmO2 during low-load contractions significantly varied with the pre-contraction protocols (Control (83.6 ± 3.0%) > LLLT + BFR (70.3 ± 2.8%) > BFR (55.4 ± 2.4%). Also, force fluctuations and MU discharge varied with the pre-contraction protocols. Multi-scale entropy and mean frequency of force fluctuations were greater in the LLLT + BFR condition (31.95 ± 0.67) than in the BFR condition (29.47 ± 0.73). The mean inter-spike interval of MUs was greater in the LLLT + BFR condition (53.32 ± 2.70 ms) than in the BFR condition (45.04 ± 1.08 ms). In particular, MUs with higher recruitment thresholds exhibited greater LLLT-related discharge complexity (LLLT + BFR (0.201 ± 0.012) > BFR (0.154 ± 0.006)).CONCLUSIONS:
LLLT pre-conditioning can minimize the BFR-related decline in muscle oxygen saturation, leading to force gradation and MU discharge in a cost-effective and complex manner.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Músculo Esquelético
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Fadiga Muscular
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Terapia com Luz de Baixa Intensidade
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Treinamento Resistido
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Contração Isométrica
Tipo de estudo:
Clinical_trials
/
Guideline
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Eur J Appl Physiol
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Taiwan