Immune System Modulation in Response to Strength Training With Blood Flow Restriction.

ABSTRACT: de Souza, TSP, de S. Pfeiffer, PA, do N. Pereira, J, Pereira Neto, EA, Dutra, TS, de Mendonça, MGL, and Cirilo-Sousa, MS. Immune system modulation in response to strength training with blood flow restriction. J Strength Cond Res 36(8): 2156-2161, 2022-This study aimed to compare strength training with blood flow restriction (ST-BFR) with multiple-set training at different intensities (30% of repetition maximum [1RM] and 75% of 1RM) for their effect on immunoinflammatory responses (total leukocytes, segmented neutrophils, lymphocytes, monocytes, and lymphocyte subpopulations). It is a randomized experimental study with a repeated-measures design with intergroup and intragroup effects of a strength training session. Eighteen physically active adults aged 20-31 years (26.17 ± 3.7 years), apparently healthy, performed a strength training session with 2 exercises. Six milliliters of blood was collected before training, immediately after training, and at 30 minutes and 24 hours after the session to perform analyses. The results showed that strength training could promote modulation (time effect) in the leukocyte count ( F = 25.86, p < 0.01, η 2 = 0.74), regardless of the method used. Neutrophils ( F = 22.71, p < 0.01, η 2 = 0.60), especially TCD4+ lymphocytes ( F = 6.33, p < 0.05, η 2 = 0, 3), were the main factors responsible for this variation. Despite the similarity, there were differences between the methods in modulations of total leukocytes ( F = 4.16, p < 0.05, η 2 = 0.36) and neutrophils ( F = 4.80, p < 0.05, η 2 = 0.39). In conclusion, compared with the multiple-set training, ST-BFR produces immunoinflammatory responses similar to low-intensity training and different from high-intensity training. However, the demargination process of some cells was different depending on the method and intensity used. Nevertheless, these variations are compatible with an appropriate recovery process because of the amplitude and length of modulation curves of leukocytes, and lymphocyte subpopulations were not compatible with immunosuppression.

Title: Blood flow restricted exercise training: Perspectives of people with chronic obstructive pulmonary disease and health professionals.

OBJECTIVE: This descriptive qualitative study explored perspectives of people with chronic obstructive pulmonary disease (COPD) and health professionals concerning blood flow restricted exercise (BFRE) training. METHODS: People living with COPD and health professionals (exercise physiologists, physiotherapists, and hospital-based respiratory nurses and doctors) participated in interviews or focus groups, which included information about BFRE training and a facilitated discussion of positive aspects, barriers and concerns about BFRE training as a possible exercise-based intervention. Sessions were audio-recorded, and transcript data analysed using inductive content analysis. RESULTS: Thirty-one people participated (people with COPD n = 6; health professionals n = 25). All participant groups expressed positive perceptions of BFRE as a potential alternative low-intensity exercise mode where health benefits might be achieved. Areas of overlap in perceived barriers and concerns included the need to address the risk of potential adverse events, suitability of training sites and identifying processes to appropriately screen potential candidates. DISCUSSION: While potential benefits were identified, concerns about determining who is safe and suitable to participate, delivery processes, health professional training and effects on a variety of health-related outcomes need to be addressed before implementation of BFRE training for people with COPD.

Effects of exercise training with blood flow restriction on vascular function in adults: a systematic review and meta-analysis.

BACKGROUND: Blood flow restricted exercise (BFRE) improves physical fitness, with theorized positive effects on vascular function. This systematic review and meta-analysis aimed to report (1) the effects of BFRE on vascular function in adults with or without chronic health conditions, and (2) adverse events and adherence reported for BFRE. METHODOLOGY: Five electronic databases were searched by two researchers independently to identify studies reporting vascular outcomes following BFRE in adults with and without chronic conditions. When sufficient data were provided, meta-analysis and exploratory meta-regression were performed. RESULTS: Twenty-six studies were included in the review (total participants n = 472; n = 41 older adults with chronic conditions). Meta-analysis (k = 9 studies) indicated that compared to exercise without blood flow restriction, resistance training with blood flow restriction resulted in significantly greater effects on endothelial function (SMD 0.76; 95% CI [0.36-1.14]). No significant differences were estimated for changes in vascular structure (SMD -0.24; 95% CI [-1.08 to 0.59]). In exploratory meta-regression analyses, several experimental protocol factors (design, exercise modality, exercised limbs, intervention length and number of sets per exercise) were significantly associated with the effect size for endothelial function outcomes. Adverse events in BFRE studies were rarely reported. CONCLUSION: There is limited evidence, predominantly available in healthy young adults, on the effect of BFRE on vascular function. Signals pointing to effect of specific dynamic resistance exercise protocols with blood flow restriction (≥4 weeks with exercises for the upper and lower limbs) on endothelial function warrant further investigation.

Are there differences in the activation of the agonist and antagonist muscles during resistance training sessions with continuous or intermittent blood flow restriction? / Existem diferenças na ativação dos músculos agonista e antagonista durante sessões de treinamento de força com restrição de fluxo sanguíneo contínua ou intermitente?

Resistance training (RT) with blood flow restriction (BFR) has been used to increase muscle strength and hypertrophy, however, the best strategy to perform BFR (continuous or intermittent) has not yet been established. The aim of this study was to analyze the chronic effect of RT with continuous or intermittent blood flow restriction (CBFR or IBFR) on muscle activation. A total of 24 men with RT experience were randomly divided into three experimental groups: low-load exercises at 20% of one repetition maximum (1RM) combined with CBFR (LL + CBFR), low-load exercises at 20% of 1RM combined with IBFR (LL + IBFR), or low-load exercises at 20% of 1RM without BFR (LL). Twelve RT sessions were performed for 6 weeks, twice a week. A comparative analysis of the activation of the biceps and triceps brachial muscles after the bench press, triceps pulley, and biceps pulley exercises did not reveal group × evaluations × sets, group × evaluations, group × sets, or evaluations × sets interactions with regard to group, evaluation, or sets (p > 0.05). However, the evaluations showed a significant increase in the LI+IBFR group after the 1st, 2nd, and 4th sets (p < 0.05) only with regard to biceps muscle activation. It was concluded that the muscle activations of the biceps and triceps are similar with regard to the bench press, triceps pulley, and biceps pulley exercises when CBFR is compared with IBFR; however, IBFR improved the muscle activation of the biceps brachial only with regard to the front pull down exercise.se....(AU)

O treinamento de força (TF) com restrição de fluxo sanguíneo (RFS) tem sido utilizado para o aumento da força e hipertrofia muscular, entretanto, ainda não foi estabelecido a melhor estratégia para realizar a RFS (contínua ou intermitente). O objetivo do estudo foi analisar o efeito crônico do TF com a RFS, contínua ou intermitente, sobre ativação muscular. Participaram do estudo 24 homens com experiência em TF que foram divididos aleatoriamente em três grupos experimentais: a) exercícios de baixa carga a 20% de 1RM combinado com a RFS contínua (BC + RFSC), b) exercícios de baixa carga a 20% de 1RM combinado com a RFS intermitente (BC + RFSI), c) exercícios de baixa carga a 20% de 1RM sem a RFS (BC). Foram realizadas 12 sessões de TF (duração de seis semanas, sendo duas vezes por semana). Na primeira e na última sessão foi avaliada a ativação muscular do bíceps e tríceps nos quatro exercícios (supino reto, puxada frontal, rosca tríceps e rosca bíceps, respectivamente). Na análise comparativa da ativação muscular do bíceps e do tríceps braquial nos exercícios: supino reto, rosca tríceps e rosca bíceps, observou-se que não existiram interações entre grupo × avaliações × séries, grupo × avaliações, grupo × séries, avaliações × séries, no grupo, nas avaliações e nas séries (p > 0,05); entretanto, nas avaliações houve aumento significativo no grupo BC+RFSI, na 1ª, 2ª e 4ª séries (p < 0,05) apenas na ativação muscular do bíceps. Conclui-se que a ativação muscular do bíceps e tríceps parecem ser semelhantes nos exercícios supino reto, rosca tríceps e rosca bíceps quando comparada a RFS contínua vs. intermitente, porém, a RFS intermitente parece melhorar a ativação muscular do bíceps braquial apenas no exercício puxada frontal....(AU)