Blood flow restriction training (BFRT) is an increasingly widespread method of exercise that involves imposed restriction of blood flow to the exercising muscle. Blood flow restriction is achieved by inflating a pneumatic pressure cuff (or a tourniquet) positioned proximal to the exercising muscle before, and during, the bout of exercise (i.e., ischemic exercise). Low-intensity BFRT with resistance training promotes comparable increases in muscle mass and strength observed during high-intensity exercise without blood flow restriction. BFRT has expanded into the clinical research setting as a potential therapeutic approach to treat functionally impaired individuals, such as the elderly, and patients with orthopedic and cardiovascular disease/conditions. However, questions regarding the safety of BFRT must be fully examined and addressed before the implementation of this exercise methodology in the clinical setting. In this respect, there is a general concern that BFRT may generate abnormal reflex-mediated cardiovascular responses. Indeed, the muscle metaboreflex is an ischemia-induced, sympathoexcitatory pressor reflex originating in skeletal muscle, and the present review synthesizes evidence that BFRT may elicit abnormal cardiovascular responses resulting from increased metaboreflex activation. Importantly, abnormal cardiovascular responses are more clearly evidenced in populations with increased cardiovascular risk (e.g., elderly and individuals with cardiovascular disease). The evidence provided in the present review draws into question the cardiovascular safety of BFRT, which clearly needs to be further investigated in future studies. This information will be paramount for the consideration of BFRT exercise implementation in clinical populations.

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Key points  Rheumatoid arthritis (RA) patients present exacerbated blood pressure responses to exercise, but little is known regarding the underlying mechanisms involved.  This study assessed autonomic and haemodynamic responses to exercise and to the isolated activation of muscle metaboreflex in post‐menopausal women with RA.  Participants with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These responses were associated with multiple pro‐ and anti‐inflammatory cytokines and with pain.  The results of the present study support the suggestion that an abnormal reflex control of circulation is an important mechanism underlying the exacerbated cardiovascular response to exercise and increased cardiovascular risk in RA. Abstract Studies have reported abnormal cardiovascular responses to exercise in rheumatoid arthritis (RA) patients, but little is known regarding the underlying mechanisms involved. This study assessed haemodynamic and sympathetic responses to exercise and to the isolated activation of muscle metaboreflex in women diagnosed with RA. Thirty‐three post‐menopausal women diagnosed with RA and 10 matched controls (CON) participated in this study. Mean arterial pressure (MAP), heart rate (HR) and muscle sympathetic nerve activity (MSNA frequency and incidence) were measured during a protocol of isometric knee extension exercise (3 min, 30% of maximal voluntary contraction), followed by post‐exercise ischaemia (PEI). Participants with RA showed greater increases in MAP and MSNA during exercise and PEI than CON (ΔMAPexercise = 16 ± 11 vs. 9 ± 6 mmHg, P = 0.03; ΔMAPPEI = 15 ± 10 vs. 5 ± 5 mmHg, P = 0.001; ΔMSNAexercise = 17 ± 14 vs. 7 ± 9 bursts min–1, P = 0.04; ΔMSNAPEI = 14 ± 10 vs. 6 ± 4 bursts min–1, P = 0.04). Autonomic responses to exercise showed significant (P < 0.05) association with pro‐ (i.e. IFN‐γ, IL‐8, MCP‐1 and TNFα) and anti‐inflammatory (i.e. IL‐1ra and IL‐10) cytokines and with pain. In conclusion, post‐menopausal women with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These findings provide mechanistic insights that may explain the abnormal cardiovascular responses to exercise in RA.

Objective: To investigate the effects of a single session of moderate-intensity and high-intensity interval exercise in cardiovascular reactivity to the cold pressor test in young adults with excess body weight. Methods: Twenty-two subjects with excess body weight (23 ± 2 years; 30.0 ± 3.4 kg·m−2) performed three sessions: (1) moderate-intensity exercise (30-minute cycling at 50%–60% of heart rate reserve); (2) high-intensity exercise (four series of 3-minute cycling at 80%–90% of heart rate reserve, interspersed by 2-minute recovery) and (3) control (i.e. 30-minute seated). Before and 30 minutes after the interventions, subjects undertook assessments of SBP/DBP and heart rate in response to the cold pressor test (1-minute rest + 1-minute hand immersed in 4°C water). Reactivity was calculated as the absolute response of SBP, DBP and heart rate to cold pressor test and compared between interventions using a two-way analysis of variance (P < 0.05). Results: Neither moderate-intensity exercise or high-intensity interval exercise attenuated SBP/DBP reactivity to cold pressor test compared with control. On the other hand, heart rate reactivity was reduced after moderate-intensity exercise compared with control (1.36 ± 8.35 bpm vs. 5.18 ± 9.45 bpm). Furthermore, moderate-intensity exercise reduced absolute levels of SBP/DBP from pre- to post-intervention. Conclusion: A single session of moderate-intensity exercise or high-intensity interval exercise did not reduce the SBP/DBP reactivity to cold pressor test. However, absolute levels of SBP/DBP were lower after moderate-intensity exercise, indicating a hypotensive effect promoted by a single session of moderate-intensity exercise in young adults with excess body weight.

We assessed physical activity using accelerometers and a questionnaire in 33 post-bariatric patients who reported to be adherent (n = 15) or not (n = 18) to social distancing due to the COVID-19 pandemic. Patients adherent to social distancing spent more time in sedentary behavior (1.1 h/day, 0.1, 2.2; p = 0.045) and less time in moderate-to-vigorous physical activity (− 12.2 min/ day, − 23.8, − 0.6; p = 0.040) vs. non-adherent ones. Bland-Altman analysis comparing objective and subjective physical activity estimates showed a bias for time spent in sedentary behavior and moderate-to-vigorous activity of 2.8 h/day and 8.5 min/day. In conclusion, post-bariatric patients who were adherent to social distancing measures were more inactive and sedentary than nonadherent ones. Strategies to increase physical activity in post-bariatric patients exposed to social distancing are necessary during the COVID-19 pandemic.