Cardiovascular drift during low intensity exercise with leg blood flow restriction

Previous studies reported that aerobic-type exercise such as walking or cycling with blood flow restriction (BFR) has been shown to elicit increases in leg muscle hypertrophy and strength, as well as improved aerobic capacity. Although previous studies investigated cardiovascular responses during a relatively short duration of exercise (∼5 min), the effects of prolonged leg muscular BFR have remained unknown. The purpose of this study was to examine the cardiovascular effects of longer duration low intensity exercise combined with BFR. Eight men performed 30 min of exercise at 40% of a predetermined maximal oxygen uptake under both BFR and normal flow (CON) conditions. Cardiovascular parameters were measured at rest and every 10 min during exercise. The main findings were that 1) the SV and HR did not change significantly between 10 to 30 min of exercise in BFR and CON conditions, although BFR-induced reduction of SV and increased HR were found at 10 min exercise compared with normal flow, 2) blood pressure was increased at 10 min of exercise in BFR compared to the CON, however the blood pressure decreased gradually with BFR from 10 to 30 min of exercise, and 3) blood lactate and RPE increased gradually during exercise with BFR. In conclusion, our results suggest that the BFR-induced reduction of SV and increased HR within the first 10 min of exercise are representative of changes in these parameters.