Purpose: We aimed to identify a blood flow restriction (BFR) endurance exercise protocol that would both maximize cardiopulmonary and metabolic strain, and minimize the perception of effort. Methods: Twelve healthy males (23 ± 2 years, 75 ± 7 kg) performed five different exercise protocols in randomized order: HI, high-intensity exercise starting at 105% of the incremental peak power (Ppeak); I-BFR₃₀, intermittent BFR at 30% Ppeak; C-BFR₃₀, continuous BFR at 30% Ppeak; CON₃₀, control exercise without BFR at 30% Ppeak; I-BFR₀, intermittent BFR during unloaded exercise. Cardiopulmonary, gastrocnemius oxygenation (StO₂), capillary lactate ([La]), and perceived exertion (RPE) were measured. Results: V̇O₂, ventilation (V̇E), heart rate (HR), [La] and RPE were greater in HI than all other protocols. However, muscle StO2 was not different between HI (set1—57.8 ± 5.8; set2—58.1 ± 7.2%) and I-BRF₃₀ (set1—59.4 ± 4.1; set2—60.5 ± 6.6%, p < 0.05). While physiologic responses were mostly similar between I-BFR₃₀ and C-BFR₃₀, [La] was greater in I-BFR₃₀ (4.2 ± 1.1 vs. 2.6 ± 1.1 mmol L¯¹, p = 0.014) and RPE was less (5.6 ± 2.1 and 7.4 ± 2.6; p = 0.014). I-BFR₃₀ showed similar reduced muscle StO₂ compared with HI, and increased blood lactate compared to C-BFR₃₀ exercise. Conclusion: Therefore, this study demonstrate that endurance cycling with intermittent BFR promotes muscle deoxygenation and metabolic strain, which may translate into increased endurance training adaptations while minimizing power output and RPE.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)