Training with blood flow restriction increases femoral artery diameter and thigh oxygen delivery during knee-extensor exercise in recreationally trained men
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In this study, we investigated the effect of training with blood flow restriction (BFR) on thigh oxygen transport and uptake, and lactate release, during exercise. Ten recreationally-trained men (50 ± 5 mL·kg-1 ·min-1 ) completed six weeks of interval cycling with one leg under BFR (BFR-leg; pressure: ∼180 mmHg) and the other leg without BFR (CON-leg). Before and after the training intervention (INT), thigh oxygen delivery, extraction, uptake, diffusion capacity, and lactate release, were determined during knee-extensor exercise at 25% iPPO (Ex1), followed by exercise to exhaustion at 90% pre-training iPPO (Ex2), by measurement of femoral-artery blood flow and femoral-arterial and -venous blood sampling. A muscle biopsy was obtained from legs before and after INT to determine mitochondrial electron-transport protein content. Femoral-artery diameter was also measured. In BFR-leg, after INT, oxygen delivery and uptake were higher, and net lactate release was lower, during Ex1 (vs. CON-leg; P < 0.05), with an 11% larger increase in workload (vs. CON-leg; P < 0.05). During Ex2, after INT, oxygen delivery was higher, and oxygen extraction was lower, in BFR-leg than CON-leg (P < 0.05), resulting in an unaltered oxygen uptake (vs. CON-leg; P > 0.05). In CON-leg, at both intensities, oxygen delivery, extraction, uptake, and lactate release, remained unchanged (P > 0.05). Resting femoral artery diameter increased with INT only in BFR-leg (∼4%; P < 0.05). Oxygen diffusion capacity was similarly raised in legs (P < 0.05). Mitochondrial protein content remained unchanged in legs (P > 0.05). Thus, BFR-interval training enhances oxygen utilization by, and lowers lactate release from, submaximally-exercising muscles of recreationally-trained men mainly by increasing leg convective oxygen transport.
|Tidsskrift||Journal of Physiology|
|Status||Udgivet - 2020|
CURIS 2020 NEXS 133