Exercise with blood flow restriction improves muscle strength and mass while preserving the vascular and microvascular function and structure of older adults

BACKGROUND: Changes in muscle mass, strength, vascular function, oxidative stress, and inflammatory biomarkers were compared in older adults after resistance training (RT) performed with low-intensity without blood flow restriction (RT-CON); low-intensity with BFR (RT-BFR); and high-intensity without BFR (RT-HI). METHODS: Thirty-two untrained individuals (72±7 y) performed a 12-week RT after being randomized into three groups: RT-CON -30% of 1 repetition maximum (RM); RT-BFR -30% of 1RM and mild BFR (50% of arterial occlusion pressure); RT-HI -70% of 1 RM. RESULTS: Improvements in handgrip strength were similar in RT-BFR (17%) and RT-HI (16%) vs. RT-CON (-0.1%), but increases in muscle mass (6% vs. 2% and -1%) and IGF-1 (2% vs. -0.1% and -1.5%) were greater (p < 0.05) in RT-BFR vs. RT-HI and RT-CON. Changes in vascular function, morphology, inflammation, and oxidative stress were similar between groups, except for time to reach maximum red blood cell velocity which showed a greater reduction (p < 0.05) in RT-BFR (-55%) vs. RT-HI (-11%) and RT-CON (-4%). CONCLUSION: RT with low intensity and mild BFR improved muscle strength and mass in older individuals while preserving vascular function. This modality should be considered an adjuvant strategy to improve muscle function in older individuals with poor tolerance to high loads.