The effect of blood‐flow‐restricted interval training on lactate and H+ dynamics during dynamic exercise in man

• Published in: Acta Physiologica Vol. 231; no. 3; pp. e13580 - n/a
• Main Authors: Christiansen, Danny, Eibye, Kasper, Hostrup, Morten, Bangsbo, Jens
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.03.2021
• Subjects: Biopsy; Blood; blood flow restriction; cycling; exercise; H+ release; Hydrogen; Interval training; lactate; Lactic acid; Leg; Muscles; pH effects; pH regulation; training; performance; H+ release; blood flow restriction; exercise; cycling; training; lactate; pH regulation
• ISSN: 1748-1708; 1748-1716
• DOI: 10.1111/apha.13580

Aim To assess how blood‐flow‐restricted (BFR) interval‐training affects the capacity of the leg muscles for pH regulation during dynamic exercise in physically trained men. Methods Ten men (age: 25 ± 4y; V˙O2max: 50 ± 5 mL∙kg−1∙min−1) completed a 6‐wk interval‐cycling intervention (INT) with one leg under BFR (BFR‐leg; ~180 mmHg) and the other without BFR (CON‐leg). Before and after INT, thigh net H+‐release (lactate‐dependent, lactate‐independent and sum) and blood acid/base variables were measured during knee‐extensor exercise at 25% (Ex25) and 90% (Ex90) of incremental peak power output. A muscle biopsy was collected before and after Ex90 to determine pH, lactate and density of H+‐transport/buffering systems. Results After INT, net H+ release (BFR‐leg: 15 ± 2; CON‐leg: 13 ± 3; mmol·min−1; Mean ± 95% CI), net lactate‐independent H+ release (BFR‐leg: 8 ± 1; CON‐leg: 4 ± 1; mmol·min−1) and net lactate‐dependent H+ release (BFR‐leg: 9 ± 3; CON‐leg: 10 ± 3; mmol·min−1) were similar between legs during Ex90 (P > .05), despite a ~142% lower muscle intracellular‐to‐interstitial lactate gradient in BFR‐leg (−3 ± 4 vs 6 ± 6 mmol·L−1; P < .05). In recovery from Ex90, net lactate‐dependent H+ efflux decreased in BFR‐leg with INT (P < .05 vs CON‐leg) owing to lowered muscle lactate production (~58% vs CON‐leg, P < .05). Net H+ gradient was not different between legs (~19%, P > .05; BFR‐leg: 48 ± 30; CON‐leg: 44 ± 23; mmol·L−1). In BFR‐leg, NHE1 density was higher than in CON‐leg (~45%; P < .05) and correlated with total‐net H+‐release (r = 0.71; P = .031) and lactate‐independent H+ release (r = 0.74; P = .023) after INT, where arterial [HCO3‐] and standard base excess in Ex25 were higher in BFR‐leg than CON‐leg. Conclusion Compared to a training control, BFR‐interval training increases the capacity for pH regulation during dynamic exercise mainly via enhancement of muscle lactate‐dependent H+‐transport function and blood H+‐buffering capacity.