"Metaboreflex and BFR" by Lin-Sheng Chen, Kazumasa Manabe et al.
  •  
  •  
 

Abstract

Low-intensity exercise combined with blood flow restriction (BFR) is effective in improving muscle strength and hypertrophy. However, exaggerated exercise pressor reflex due to restricted venous outflow and metabolite accumulation triggering metaboreflex has been raised as a concern during BFR training. Additionally, the impact of BFR training on arterial vascular function remains highly controversial. PURPOSE: To evaluate hemodynamic responses to isometric exercise with and without BFR using the post-exercise ischemia (PEI) protocol and examine the acute changes in vascular function before and after BFR isometric exercise. METHODS: Nine apparently healthy young adults (5 females, 28±4 years) completed three sets of 2-minute single-arm isometric handgrip exercise (30% of maximum voluntary contraction) with or without BFR in two laboratory visits in a randomized order. A nylon blood pressure cuff was placed on the proximal end of the upper arm and inflated to 80 mmHg during BFR isometric exercise. Immediately following the cessation of isometric exercise, a 2-minute PEI was implemented to isolate the muscle metaboreflex. Beat-by-beat mean arterial pressure (MAP) and heart rate (HR) were measured throughout the exercise and PEI on the contralateral non-exercising arm. Flow-mediated dilation (FMD), a measure of endothelial-dependent vasodilation, was assessed using ultrasound before and after the exercise. RESULTS: Compared with isometric exercise alone, ΔMAP was greater during BFR isometric exercise and PEI (set 1: 27±11 vs. 14±10 mmHg; set 2: 33±12 vs. 18±9 mmHg; set 3: 32±13 vs. 18±7 mmHg; PEI: 24±11 vs. 14±7 mmHg, all p0.05). CONCLUSION: Greater hemodynamic responses were observed during isometric exercise with BFR and PEI when compared with isometric exercise alone, suggesting that BFR training may elicit exaggerated muscle metaboreflex. Vascular function remained unchanged following BFR training.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.