Cardiorespiratory, Metabolic, and Perceptual Responses to Blood Flow Restricted Running in Female Distance Runners

Low-intensity exercise with a blood flow restriction (BFR) has been shown to be an effective alternative to high-intensity (HI) training. This study evaluated heart rate (HR), oxygen consumption (Vo(2)), blood lactate (BLa), and ratings of perceived exertion (RPE) during blood flow restricted running and HI running in competitive female runners. Fifteen female distance runners (23 +/- 4 years, 1.67 +/- 0.50 m, 57.6 +/- 5.7 kg) completed 3 randomized 12-minute running conditions: low-intensity (LI) control at 40% Vo(2)max, HI at 80% Vo(2)max, and low-intensity with a BFR (LI-BFR) at 40% Vo(2)max. Vo(2), HR, RPE (6-20 scale), and BLa were measured before, during, and after exercise. Significance was set at p < 0.05. Vo(2) differed between the conditions (p < 0.001), because HI (39.4 +/- 3.9 ml center dot kg(-1)center dot min(-1)) was greater than LI-BFR (25.3 +/- 2.6 ml center dot kg(-1)center dot min(-1)) and both were higher than LI (22.5 +/- 3.1 ml center dot kg(-1)center dot min(-1)). Heart rate differed between the 3 conditions (p < 0.001) and averaged 166 +/- 8, 142 +/- 13, and 124 +/- 11 b center dot min(-1) for HI, LI-BFR, and LI, respectively. Average BLa across conditions was similar in HI and LI-BFR conditions (1.76 +/- 0.48 and 1.82 +/- 0.48 mmol, respectively; p > 0.05), and both were higher than LI (1.06 +/- 0.18 mmol; p < 0.017). Ratings of perceived exertion in the HI (11 +/- 2) and LI-BFR (12 +/- 2) conditions were similar (p = 0.236), while LI (9 +/- 1) was lower (p < 0.001). High-intensity running elicits the greatest responses in HR and Vo(2) compared with LI and LI-BFR, suggesting more robust and effective long-term training responses could occur. Low-intensity with a BFR has more pronounced cardiovascular and metabolic effects than LI running but generated the greatest RPE values creating concerns about acceptability and compliance.