Blood flow restriction: rationale for improving bone

Abstract

Low intensity exercise with blood flow restriction has been shown to increase muscle hypertrophy and strength similar to high intensity resistance exercise. Interestingly, low intensity resistance exercise to failure has shown the same muscle protein synthesis response as higher intensity exercise, questioning the need for blood flow restriction during low intensity exercise. The purpose of this manuscript is to discuss the mechanisms and potential benefits of blood flow restricted exercise on bone adaptation and provide rationale as to why low load resistance exercise to failure would be unlikely to produce these benefits. The studies completed thus far support the hypothesis that training with blood flow restriction may provide not only a novel modality to induce adaptation in muscle but also bone, which was previously thought to only occur with higher intensity/impact exercise. We hypothesize that the main mechanism behind the proposed favorable bone responses observed thus far is through increased intramedullary pressure and interstitial fluid flow within the bone caused by venous occlusion. Therefore, although similar muscular benefits may be observed from low intensity exercise performed to failure (e.g. strength, hypertrophy, and endurance), the response of bone might be different, highlighting the potential importance of the blood flow restriction stimulus.