Exploring immediate cardiorespiratory responses: low-intensity blood flow restricted cycling vs. moderate-intensity traditional exercise in a randomized crossover trial

• Published in: BMC sports science, medicine & rehabilitation Vol. 16; no. 1; pp. 172 - 12
• Main Authors: Haile, Sarah R, Kuhn, Manuel, Kohlbrenner, Dario, Kläy, Adrian, Lüchinger, Martin, Mayer, Laura C, Clarenbach, Christian F, Kohler, Malcolm, Sievi, Noriane A, Andrist, Belinda, Radtke, Thomas
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 15.08.2024; BioMed Central; BMC
• Subjects: Analysis; Blood flow; Blood flow restriction training; Cardiorespiratory response; Cycling exercise; Exercise; Healthy individuals; Interval training; Occlusion
• ISSN: 2052-1847; 2052-1847
• DOI: 10.1186/s13102-024-00951-0

Purpose Blood-flow restriction (BFR) endurance training may increase endurance performance and muscle strength similar to traditional endurance training while requiring a lower training intensity. We aimed to compare acute cardiorespiratory responses to low-intensity interval exercise under BFR with moderate-intensity traditional interval exercise (TRA). Methods We conducted a randomized crossover study. The protocol involved three cycling intervals interspersed with 1 min resting periods. With a 48-h washout period, individuals performed the protocol twice in random order: once as BFR-50 (i.e., 50% incremental peak power output [IPPO] and 50% limb occlusion pressure [LOP]) and once as TRA-65 (65% IPPO without occlusion). TRA-65 intervals lasted 2 min, and time-matched BFR-50 lasted 2 min and 18 s. Respiratory parameters were collected by breath-by-breath analysis. The ratings of perceived breathing and leg exertion (RPE, 0 to 10) were assessed. Linear mixed models were used for analysis. Results Out of the 28 participants initially enrolled in the study, 24 healthy individuals (18 males and 6 females) completed both measurements. Compared with TRA-65, BFR-50 elicited lower minute ventilation (VE, primary outcome) (-3.1 l/min [-4.4 to -1.7]), oxygen consumption (-0.22 l/min [-0.28 to -0.16]), carbon dioxide production (-0.25 l/min [-0.29 to -0.20]) and RPE breathing (-0.9 [-1.2 to -0.6]). RPE leg was significantly greater in the BFR-50 group (1.3 [1.0 to 1.7]). Conclusion BFR endurance exercise at 50% IPPO and 50% LOP resulted in lower cardiorespiratory work and perceived breathing effort compared to TRA at 65% IPPO. BFR-50 could be an attractive alternative for TRA-65, eliciting less respiratory work and perceived breathing effort while augmenting perceived leg muscle effort. Trial registration NCT05163600; December 20, 2021. Keywords: Blood flow restriction training, Occlusion, Interval training, Cycling exercise, Cardiorespiratory response, Healthy individuals