Blood flow restriction during a 6-day HIIT microcycle provided similar ~4% improvements in 5-minute maximal cycling power output as traditional HIIT in well-trained cyclists.
RCT (n=17)
Does high-intensity interval training with blood flow restriction improve endurance performance and muscular adaptations compared to traditional HIIT in well-trained cyclists?
Blood flow restriction during a 6-day HIIT microcycle allows well-trained cyclists to achieve similar performance gains at a significantly lower external workload compared to traditional HIIT.
Absolute Event Rate: 4% vs 4%
Background: Blood flow restriction (BFR) allows exercise at lower external load with similar or greater improvements compared with traditional training in non-trained individuals. However, the effect in well-trained competitive athletes is unclear. The aim of this study was to compare effort-matched high-intensity interval training (HIIT) microcycles performed with or without BFR on endurance performance and muscular adaptations in well-trained cyclists. Methods: 17 well-trained cyclists (31 ± 9 years; VO2max: 67 ± 6ml×kg-1×min-1) were randomized to groups performing five HIIT sessions (6 x 5 min intervals with 2.5 min of recovery) with (BFR) or without (HIIT) thigh cuffs occluding the legs. VO2max, power output at 4 mmoL/L blood lactate (LT4), mean power output during 5-minute maximal cycling (MPO5min), percentage of VO2max used at LT4 (%VO2max @LT4), haemoglobin mass and blood volume (BV) were assessed. Muscle biopsies from m. vastus lateralis evaluated muscle cross-sectional area (CSA), capillaries, citrate synthase (CS), Hydroxyacyl-Coenzyme A dehydrogenase (HADH) and cytochrome c oxidase 4 (COX4). Results: The BFR group trained at a 42% lower power output than HIIT group (177±3 W vs 307±8 W, respectively, p<0.01), but with no differences in heart rate or rate of perceived exertion. Both groups improved MPO5min by ⁓4%, with no changes in LT4, VO2max, haemoglobin mass and BV. HIIT showed a significant reduction in CSA for type 2 muscle fibers compared with BFR, whereas no changes were found in the other muscle analyses. Conclusions: BFR applied during a 6-day interval microcycle provides similar performance gains as traditional HIIT in well-trained cyclists.
Zambolin et al. (Mon,) conducted a rct in Well-trained cyclists (n=17). High-intensity interval training (HIIT) with blood flow restriction (BFR) vs. HIIT without BFR was evaluated on Mean power output during 5-minute maximal cycling (MPO5min). Blood flow restriction during a 6-day HIIT microcycle provided similar ~4% improvements in 5-minute maximal cycling power output as traditional HIIT in well-trained cyclists.