Blood flow–restricted walking does not result in an accumulation of metabolites

The American College of Sports Medicine recommends lifting a weight of at least 70% of one's concentric one repetition maximum to achieve muscular hypertrophy as it is believed that anything below this intensity does not produce significant muscle growth. Recent studies have found muscle hypertrophy to occur with low-intensity 'aerobic-like' exercise with the application of blood flow restriction (BFR) to the limbs. Previous research with low load resistance training has shown that elastic knee wraps provide a practical means to induce elevations in whole blood lactate (WBL), which has been hypothesized to result in many of the adaptations observed with this type of exercise. However, this has yet to be investigated with low-intensity walking. Thus, the purpose of this paper was to determine the degree to which WBL increases with practical BFR walking. Exercise consisted of five 2-min bouts of walking at 75 m per min on a motor-driven treadmill with a 1-min rest period following each exercise bout. Participants completed the walking with (BFR) and without [control (CON)] restriction to the upper thigh in a randomized order. Practical BFR with elastic knee wraps did statistically increase WBL compared with CON; however, this was not considered a real change because the minimal difference between conditions was not exceeded. In conclusion, metabolic stress is not increased following practical BFR walking exercise. This study may provide an explanation for the lower hormone response observed with BFR walking and provide further evidence that mechanisms other than metabolic accumulation exist with BFR.