ABSTRACT
Background: The present study analyzed the acute responses of parathyroid hormone (PTH) and bone-specific alkaline phosphatase (BSAP) to the low-intensity resistance exercise with blood flow restriction using different occlusion pressures. Methods: Twelve women completed the three protocols of this crossover study: resistance exercise without blood flow restriction (RE), resistance exercise with blood flow restriction and occlusion pressure corresponding to 70% of systolic blood pressure (RE + BFR70), and resistance exercise with blood flow restriction and occlusion pressure corresponding 130% of systolic blood pressure (RE + BFR130). All exercises were performed in a guided squat apparatus with load corresponded to 30% of one-repetition maximum test. Results: Relative to resting levels, PTH concentrations decreased significantly (p = .000) post-exercise in all groups and increased significantly (p = .000) 15 min post-exercise in RE + BFR70 and RE + BFR130 groups; PTH concentrations returned to resting levels after the 30-min recovery period in all groups. There was no significant difference (p >.05) between BSAP values at rest and 30 min post-exercise. Conclusion: In conclusion, our results showed that protocols with blood flow restriction using occlusion pressures equivalent to 70% and 130% of systolic blood pressure were more effective than RE alone to induce PTH peaks, and to promote a metabolic condition favorable to bone anabolism.
ABSTRACT
ABSTRACT The present study aimed to evaluate the acute behavior of the brachial artery resistance index (BARI) and popliteal artery resistance index (PARI) in response to low intensity strength exercises involving small (SMG) and large muscle groups (LMG) performed with and without blood flow restriction. Eleven men (age 23 ± 3.29 years) underwent a four-arm, randomized, cross-over experiment: Small muscle group exercise (SMG), small muscle groups with blood flow restriction (SMG+BFR), large muscle groups (LMG) and large muscle groups with blood flow restriction (LMG+BFR). The behavior of BARI and PARI was evaluated at rest, immediately after exercise, and at 15 and 30 minutes during recovery. Data analysis showed a significant reduction of the BARI from rest to post-exercise only in the protocols involving SMG, regardless of the BFR (p <0.05). Protocols involving LMG, with or without BFR, did not affect PARI (p> 0.05), but were efficient to promote significant increases in BARI (p <0.05) immediately after exercise. Our findings indicate that the exercises involving SMG, regardless of BFR, are efficient to promote local vasodilatation (brachial artery), but without systemic effects. None of the analyzed protocols affected the PARI behavior.
RESUMO O presente estudo objetivou avaliar o comportamento agudo do índice de resistência da artéria braquial (IRAB) e da artéria poplítea (IRAP) em resposta a exercícios de força de baixa intensidade envolvendo pequenos (PGM) e grandes grupos musculares (GGM), realizado com e sem restrição de fluxo sanguíneo. Onze homens (idade 23 ± 3,29 anos) realizaram um experimento randomizado, cruzado, com quatro braços: Exercício para pequenos grupos musculares (PGM), pequenos grupos musculares com restrição de fluxo sanguíneo (PGM+RFS), grandes grupos musculares (GGM) e grandes grupos musculares com restrição de fluxo sanguíneo (GGM+RFS). O comportamento de IRAB e IRAP foi avaliado em repouso, mediatamente após o exercício, e aos 15 e 30 minutos da recuperação. A análise dos dados mostrou uma redução significativa do IRAB do repouso para o pós-exercício apenas nos protocolos de PGM com ou sem RFS (p <0,05). Protocolos envolvendo GGM, independentemente do BFR, não afetaram o IRAP (p> 0,05), porém, foram eficientes para promover aumentos significativos do IRAB (p <0,05) imediatamente após o exercício. Nossos achados indicam que os exercícios envolvendo PGM, independentemente da BFR, são capazes de promover a vasodilatação local (artéria braquial), porém, sem efeitos sistêmicos. Nenhum dos protocolos analisados afetou o comportamento do IRAP.
Subject(s)
Humans , Male , Adult , Vasodilation , Muscle Strength , Physical Endurance , Popliteal Artery , Pulse/methods , Rest , Behavior , Brachial Artery , Arterial PressureABSTRACT
Abstract The aim of this study was to analyze the acute hemodynamic responses to strength exercise with blood flow restriction involving small muscle groups. The sample consisted of 10 male volunteers (22.6 ± 2.07 years, 1.78 ± 0.06 m, 76.32 ± 13.36 kg) who randomly performed two experimental protocols involving the elbow flexion exercise with the dominant arm: strength exercise of the elbow flexors with blood flow restriction (EFBFR) and strength exercise of the elbow flexors without blood flow restriction (EEF). A cross-over design with a seven to ten days interval between the experimental protocols was used. Systolic blood pressure (SBP), diastolic (DBP) and mean (MAP), pulse pressure (PP), heart rate (HR) and double product (DP) were evaluated at rest, immediately after exercise and at 15 minutes of recovery. SBP, DBP and MAP presented a significant increase (p <0.05) immediately after EFBFR when compared to the protocol without blood flow restriction, returning to rest values at the 15 minutes of recovery. DBP significantly reduced (p <0.05) in the recovery period only in the EFBFR experiment and HR increased post-effort in both experiments. The PP and DP did not change between the different times, regardless of the protocol.The results of the present study allow us to conclude that strength exercise with BFR involving small muscle groups was more efficient than exercise without BFR to promote acute changes in hemodynamic responses and that BFR did not represent a cardiovascular risk considering its effects on PP.
Resumo O presente estudo objetivou analisar as respostas hemodinâmicas agudas ao exercício de força com restrição do fluxo sanguíneo (RFS) realizado com pequenos grupos musculares. A amostra foi composta por 10 voluntários do sexo masculino (22,6 ± 2,07 anos, 1,78 ± 0,06 m, 76,32 ± 13,36 kg), que realizaram de forma aleatória os protocolos envolvendo o exercício de flexão da articulação do cotovelo, com membro dominante (rosca concentrada de bíceps) realizado com (ERFS) e sem restrição do fluxo sanguíneo (ESR). Utilizou-se o desenho cruzado, com intervalo de sete a dez dias entre os experimentos. Foram avaliadas: pressão arterial sistólica (PAS), diastólica (PAD) e média (PAM); pressão de pulso (PP), frequência cardíaca (FC) e duplo produto (DP), em repouso, imediatamente após o esforço, e após o esforço na fase de recuperação de 15 minutos. A PAS, PAD e PAM apresentaram elevação significativa (p <0,05) imediatamente após a realização do ERFS, quando comparadas ao protocolo sem restrição, retornando aos valores de repouso após a recuperação. A PAD reduziu significativamente (p <0,05) na recuperação, apenas no experimento ERFS e a FC elevou no pós-esforço em ambos os experimentos. A PP e o DP não sofreram alterações entre os diferentes momentos de avaliação, independentemente do protocolo. Os resultados do presente estudo permitem concluir que o exercício de força com RFS envolvendo pequenos grupos musculares foi mais eficiente que o exercício sem restrição para promover alterações agudas das respostas hemodinâmicas e que a RFS não representou um risco cardiovascular, considerando seus efeitos sobre a PP.
