Low-Intensity Exercise with Blood Flow Restriction Increases Muscle Strength without Altering hsCRP and Fibrinogen Levels in Healthy Subjects

Abstract

Strengthening exercise combined with blood flow restriction potentially increases muscle strength. This type of exercise does not require heavy weight liftings and is a feasible method to be performed by persons suffering illnesses. However, strengthening exercise may induce inflammatory responses due to muscle and vascular endothelial damage. This study aimed to investigate alterations of high-sensitivity C-reactive protein (hsCRP) and fibrinogen levels in healthy subjects after five weeks of low intensity resistance training (LIRT) with blood flow restriction (BFR) on increasing strength in comparison with high intensity resistance training (HIRT) and LIRT alone, and to evaluate aspects related to the relative safety of LIRT + BFR. Eighteen healthy subjects were randomized into 3 groups. The HIRT group: 70% of One-Repetition Maximum (1-RM); LIRT + BFR group: 30% of 1-RM with BFR (a modified 13-cm wide cuff was used); LIRT group: 30% of 1-RM. The peak torque of isokinetic contraction of the left elbow flexor in each subject was measured before and after 5 weeks of resistance exercises to determine any increases in the left biceps brachii muscle strength. Blood markers of homeostasis (fibrinogen) and inflammation (hsCRP) were also measured before and after five weeks of training. Significant increases of strength were demonstrated between the five weeks of resistance exercises in the HIRT group (P = 0.003) and the LIRT + BFR group (P = 0.001). Peak torque of isokinetic contraction of the left flexor elbow joint at 60° per second angular velocity showed that the LIRT + BFR group produced the greatest peak torque increase than the HIRT group. There were no significant changes in the hsCRP levels in all the groups (P > 0.05) after five weeks of intervention. No significant differences of fibrinogen levels were found in the HIRT group (P = 0.500) and the LIRT + BFR group (P = 0.405), but significant decreases were found in the fibrinogen levels in the LIRT group (P = 0.017). The LIRT + BFR increases in the muscle strength were as significant as in HIRT without altering the fibrinogen and hsCRP levels in the healthy subjects. In this study, LIRT + BFR showed increase muscle strength without any vascular problems.

Perioperative Blood Flow Restriction Rehabilitation in Patients Undergoing ACL Reconstruction: A Systematic Review

“…1,61 The anaerobic conditions of BFR induce an angiogenic stimulus through upregulation of vascular endothelial growth factor. 19,38 In addition, the hypoxic stimuli may stimulate the mobilization and recruitment of endothelial progenitor stem cells, improving the regenerative potential in healthy volunteers. 54 The muscle hypertrophy induced during low-intensity resistance training with BFR is an attractive method of postsurgical rehabilitation in ACLR in that it avoids placing high loads on the graft in the immediate postoperative period and provides rehabilitation options for the elderly and other patients with severe endurance or strength deficiency.…”

The Increase Level of Muscle Adductor in Idiopathic Vocal Cord Adductor Paralysis Post Biofeedback Vocal Therapy

“…The BF voice therapy is started to be reported in the literature with a good result, that is the improvement of vocal cord deviation. According to the previous study, it was reported that 21 normal persons and 7 patients with vocal nodule who underwent the BF therapy session shows that there are a significant difference in EMG score, and the decrease level of muscle tension 13 . It revealed that there were positive correlation between the EMG result with the voice quality assessment.…”

The physiological, morphological and functional responses to resistance exercise with blood flow restriction: an examination of protocol type and exercise load

“…This is derived from various blood markers such as D-dimer, fibrin degradation product (FDP), fibrinogen, and prothrombin time, all of which indicate coagulation activity. These factors do not appear to be influenced acutely [100,103,228], or chronically [54,169], following a period of BFR exercise/training.…”

“…In human skeletal muscle, it appears that periods of ischemia followed by reperfusion of up to 1.5 hours can be tolerated without any sign of structural, ultrastructural or immunohistochemical damage [271]. Given that the duration of BFR exercise is typically below 30 minutes [292], and doesn't involve complete occlusion of arterial blood flow [189], this may explain why studies investigating the potential for ischemic-reperfusion injury with BFR have failed to note elevations in markers of oxidative stress or inflammation that typically present with this injury [54,169].…”

“…This is due to concerns that BFR may promote venous stasis and endothelial injury, which make up two of the three categories of factors that are thought to contribute to thrombosis, as described in Virchow's triad [85]. Despite this belief, several studies have demonstrated that BFR in combination with RE enhances the fibrinolytic potential, without influencing the coagulation cascades in the body [54,100,103,169,228]. This is derived from various blood markers such as D-dimer, fibrin degradation product (FDP), fibrinogen, and prothrombin time, all of which indicate coagulation activity.…”