Effect of walking with blood flow restriction in elderly women with osteoporosis/osteopenia / Efeito da caminhada com restrição do fluxo sanguíneo em idosas com osteoporose/osteopenia

Abstract Introduction The preservation of bone mass in elderly women is associated with better levels of practice of systematic physical exercises. Aerobic training combined with blood flow restriction seems to be a new alternative that determines this process, but knowledge gaps are still observed when referring to exercise associated with blood flow restriction (BFR) and adaptations on bone variables. Objective To analyze the chronic effects of aerobic training with and without BFR on bone mineral density and bone biomarker osteocalcin concentrations in older women. Methods Thirty women were randomized into the following groups: walking on a treadmill at low intensity with BFR; moderate treadmill walking with no BFR; only BFR (no exercise) for 20 minutes, twice a week, for 24 weeks. Bone mineral density was measured before and 24 weeks after intervention. Blood serum osteocalcin concentrations were measured before, 12 and 24 weeks after intervention. Results There were no differences between groups in bone mineral density (femoral neck, p = 0.31; total femur, p = 0.17; lumbar spin, p = 0.06) and osteocalcine (W(2) = 0.27; p = 0.87) ouctomes after 24 weeks of intervention. Conclusion There was no difference between walking training, blood flow restriction only, or walking+blood flow restriction on bone mineral density and osteocalcin concentrations after 24-weeks of intervention in older women with osteopenia/osteoporosis.

Resumo Introdução A preservação da massa óssea em mulheres idosas está associada a melhores níveis de prática de exercícios físicos sistemáticos. O treinamento aeróbico combinado com restrição de fluxo sanguíneo (RFS) parece ser uma nova alternativa que determina esse processo, mas ainda são observadas lacunas de conhecimento quando se refere ao exercício associado à RFS e adaptações nas variáveis ósseas. Objetivo Analisar os efeitos crônicos do treinamento aeróbico com e sem RFS na densidade mineral óssea e nas concentrações do biomarcador ósseo osteocalcina em mulheres idosas. Métodos Trinta mulheres foram randomizadas nos seguintes grupos: caminhada em esteira de baixa intensidade com RFS; caminhada moderada em esteira sem RFS; apenas RFS (sem exercícios) por 20 minutos, duas vezes por semana, durante 24 semanas. A densidade mineral óssea foi medida antes e 24 semanas após a intervenção. As concentrações séricas de osteocalcina no sangue foram medidas antes, 12 e 24 semanas após a intervenção. Resultados Não houve diferenças entre os grupos na densidade mineral óssea (colo do fêmur, p = 0,31; fêmur total, p = 0,17; giro lombar, p = 0,06) e osteocalcina (W(2) = 0,27; p = 0,87) após 24 semanas de intervenção. Conclusão Não houve diferença entre treinamento de caminhada, apenas restrição de fluxo sanguíneo ou caminhada + restrição de fluxo sanguíneo na densidade mineral óssea e nas concentrações de osteocalcina após 24 semanas de intervenção em mulheres idosas com osteopenia/osteoporose.

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.

Effects of Different Percentages of Blood Flow Restriction on Energy Expenditure.

The study aimed to analyze the effect of different levels of blood flow restriction (BFR) on energy expenditure (EE) and subjective perceptions of discomfort (SPD) during aerobic exercises. A sample group of 24 young men was required to walk on a treadmill for 14 min at 40% of their maximum speed, with 4 different percentages of BFR (0, 50, 80 and 100%) applied in the lower limbs (LL) once a week with a 7-day interval between the 4 evaluations. EE data were collected during the exercise periods; SPD data were collected after the exercises. There was a significant increase in EE at 50, 80 and 100% BFR compared to the condition without BFR, and between 50 and 100% BFR; however, there were no differences between 50 and 80% and 80 and 100% BFR. Discomfort showed a significant increase according to the increase in BFR. During the walking exercises with BFR, the EE strongly increased until 50% of BFR; after this level the additional increases slowed. It can be concluded that when performing aerobic exercises with BFR, there is no need to use BFR levels above 50% to reach satisfying level of EE with only a moderate level of discomfort to the practitioner. This study was registered in the Brazilian Registry of Clinical Trials (REBEC) under number RBR-3XHSJX.