Search

Low-intensity resistance exercise can effectively induce muscle hypertrophy and increases in strength when combined with moderate blood flow restriction ( BFR). As this type of exercise does not require lifting heavy weights, it might be a feasible method of cardiac rehabilitation, in which resistance exercise has been recommended to be included. Although previous studies with healthy subjects showed relative safety of BFR exercise, we cannot exclude the possibility of unfavourable effects in patients with cardiovascular disease. We therefore aimed to investigate haemostatic and inflammatory responses to BFR exercise in patients with ischaemic heart disease ( IHD). Nine stable patients with IHD who were not taking anticoagulant drugs performed four sets of knee extension exercise at an intensity of 20% one-repetition maximum (1 RM) either with or without BFR. Blood samples were taken before, immediately after and 1 h after the exercise session and analysed for noradrenaline, D-dimer, fibrinogen/fibrin degradation products ( FDP) and high-sensitive C-reactive protein (hs CRP). Plasma noradrenaline concentration increased after the exercise, and the increase was significantly larger after the exercise with BFR than without BFR. On the other hand, increases in concentrations of plasma D-dimer and serum hs CRP were independent of the condition. However, increases in D-dimer and hs CRP were no longer observed after plasma volume correction, suggesting that hemoconcentration was responsible for these increases. Plasma FDP concentration did not change after the exercise. These results suggest that applying BFR during low-intensity resistance exercise does not affect exercise-induced haemostatic and inflammatory responses in stable IHD patients. [ABSTRACT FROM AUTHOR]

Summary Venous compliance declines with age and improves with chronic endurance exercise. KAATSU, an exercise combined with blood flow restriction (BFR), is a unique training method for promoting muscle hypertrophy and strength gains by using low-intensity resistance exercises or walking. This method also induces pooling of venous blood in the legs. Therefore, we hypothesized that slow walking with BFR may affect limb venous compliance and examined the influence of 6 weeks of walking with BFR on venous compliance in older women. Sixteen women aged 59-78 years were partially randomized into either a slow walking with BFR group ( n = 9, BFR walk group) or a non-exercising control group ( n = 7, control group). The BFR walk group performed 20-min treadmill slow walking (67 m min−1), 5 days per week for 6 weeks. Before (pre) and after (post) those 6 weeks, venous properties were assessed using strain gauge venous occlusion plethysmography. After 6 weeks, leg venous compliance increased significantly in the BFR walk group (pre: 0·0518 ± 0·0084, post: 0·0619 ± 0·0150 ml 100 ml−1 mmHg−1, P<0·05), and maximal venous outflow (MVO) at 80 mmHg also increased significantly after the BFR walk group trained for 6 weeks (pre: 55·3 ± 15·6, post: 67·1 ± 18·9 ml 100 ml−1 min−1, P<0·01), but no significant differences were observed in venous compliance and MVO in the control group. In addition, there was no significant change in arm compliance in the BFR walk group. In conclusion, this study provides the first evidence that 6 weeks of walking exercise with BFR may improve limb venous compliance in untrained elder female subjects. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that even a low-intensity resistance exercise can effectively induce muscle hypertrophy and strength increase when combined with moderate blood flow restriction (BFR) into the exercising muscle. Although serious side effects of low-intensity resistance exercise with BFR have not been reported, a concern of thrombosis has been suggested, because this type of exercise is performed with restricted venous blood flow and pooling of blood in extremities. Thus, the purpose of this study was to investigate the effects of low-intensity resistance exercise with BFR on coagulation system in healthy subjects. Ten healthy men (25·1 ± 2·8 year) performed four sets of leg press exercises with and without BFR (150–160 mmHg) at an intensity of 30% of one-repetition maximum (1RM). In each exercise session, one set with 30 repetitions was followed by three sets with 15 repetitions. Blood samples were taken before, and 10 min, 1, 4 and 24 h after the exercise. Prothrombin fragment 1 + 2 (PTF) and thrombin–antithrombin III complex (TAT) were measured as markers of thrombin generation, whereas D-dimer and fibrin degradation product (FDP) were measured as markers of intravascular clot formation. Changes in plasma volume (PV) were calculated from haemoglobin and hematocrit values. PV reduction was significantly greater after the exercise with BFR than without ( P<0·05). However, neither markers of thrombin generation nor intravascular clot formation increased after the exercises. These results suggest that low-intensity resistance exercise with BFR does not activate coagulation system in healthy subjects. [ABSTRACT FROM AUTHOR]