Practical Blood Flow Restriction Training: New Methodological Directions for Practice and Research

Innovations in the Assessment of Skeletal Muscle Health: A Glimpse into the Future

Skeletal muscle is the largest organ system in the human body and plays critical roles in athletic performance, mobility, and disease pathogenesis. Despite growing recognition of its importance by major health organizations, significant knowledge gaps remain regarding skeletal muscle health and its crosstalk with nearly every physiological system. Relevant public health challenges like pain, injury, obesity, and sarcopenia underscore the need to accurately assess skeletal muscle health and function. Feasible, non-invasive techniques that reliably evaluate metrics including muscle pain, dynamic structure, contractility, circulatory function, body composition, and emerging biomarkers are imperative to unraveling the complexities of skeletal muscle. Our concise review highlights innovative or overlooked approaches for comprehensively assessing skeletal muscle in vivo. We summarize recent advances in leveraging dynamic ultrasound imaging, muscle echogenicity, tensiomyography, blood flow restriction protocols, molecular techniques, body composition, and pain assessments to gain novel insight into muscle physiology from cellular to whole-body perspectives. Continued development of precise, non-invasive tools to investigate skeletal muscle are critical in informing impactful discoveries in exercise and rehabilitation science.

Enhanced Pain Relief and Muscle Growth in Individuals with Low Back Instability: The Impact of Blood Flow Restriction Exercise during Sit to Stand Movements

BACKGROUND Blood flow restriction exercise (BFRE) improves muscle strength at a relatively low intensity by temporarily restricting blood flow. This study compared pain and quadriceps muscle mass (QMM) in 40 patients with lower back pain (LBP) undertaking sit-to-stand (STS) exercise with and without blood flow restriction. MATERIAL AND METHODS Forty adults were divided into 2 groups, and the experimental group (n=20) performed an STS exercise with BFRE, and the control group (n=20) performed an STS exercise without BFRE. Blood pressure, including systolic blood pressure (SBP) and diastolic blood pressure (DBP), was measured using a portable blood pressure monitor. Saturation of percutaneous oxygen (SpO2) was measured using oxygen saturation. Pain was measured using the visual analog scale (VAS) and the Oswestry disability index (ODI). QMM was assessed using ultrasonography. RESULTS Data were analyzed using paired and independent t tests. SBP (P=.000), DBP (P=.004), and SpO2 (P=.001) were significantly different in the experimental group, both before and during the intervention. The VAS scores showed a statistically significant difference in the post-test (P=.003) and rate of change (P=.009) between the groups. The ODI scores showed statistically significant differences in the post-test (P=.000) and rate of change (P=.001) comparison between the groups. The rate of change in QMM, including the rectus femoris (P=.000), vastus intermedius (P=.004), vastus medialis (P=.001), and vastus lateralis (P=.014), increased significantly in the experimental group compared to that in the control group. CONCLUSIONS This study demonstrates that the additive effect of BFRE on pain relief and QMM increase, thus contributing to existing knowledge about therapeutic exercise for the effective management of LBP.

Clinic and Home-Based Exercise with Blood Flow Restriction Resolves Thigh Muscle Atrophy after Anterior Cruciate Ligament Reconstruction with the Bone-Patellar Tendon-Bone Autograft: A Case Report

Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.

Effect of High-Intensity Interval Training Combined with Blood Flow Restriction at Different Phases on Abdominal Visceral Fat among Obese Adults: A Randomized Controlled Trial

BACKGROUND

High-intensity interval training (HIIT) and blood flow restriction (BFR) represent a critical nonpharmacological strategy to reduce the excess deposition of visceral fat, as well as relevant complications, among obese populations. Applying BFR at diverse phases may have different effects. Therefore, the exercise program of this study combined HIIT with BFR, so as to explore the effect of BFR on abdominal visceral fat area and its mechanism in different periods of HIIT. The aim is to provide a more effective exercise prescription for obese people who want to reduce visceral fat quickly.

METHODS

This study was a randomized controlled trial involving 72 obese adults. One week before intervention, both regional and whole-body fat masses, abdominal subcutaneous and visceral fat areas, variables of blood metabolism, and VO_2max were recorded. Additionally, subjects with a matched fat percentage were randomized as a no-training control (C), HIIT (H), HIIT with BFR during interval (I), and HIIT with BFR during exercise (E) groups for 24 sessions within a 12-week period, using a cycle ergometer. During session one, this study recorded blood lactate, specific serum lipolytic hormones, rating of perceived exertion (RPE), and exercise heart rate (HR) and compared them among three groups. The baseline tests were repeated at 1 week after intervention.

RESULTS

There was no significant statistical difference in the indicators of each group at baseline (p > 0.05). The improvement of trunk fat mass and fat percentage of the I and E groups markedly increased relative to the H group (p < 0.05). Meanwhile, the I group had improved android fat mass and whole-body fat mass relative to group H (p < 0.05). Those exercise groups had markedly improved indices compared with the C group (p < 0.05). Additionally, the reduction in the I group had remarkably superior abdominal visceral fat areas (AVFA) to the H and E groups (p < 0.05). Immediately and 30 min following exercise, the E and I groups had remarkably increased growth hormone (GH) compared with the H group (p < 0.05). After exercise, the I group showed markedly increased epinephrine (EPI) compared with the H group (p < 0.05). The LA level in the I group evidently increased relative to the E group (p < 0.05), while that in the E group evidently increased compared with the H group (p < 0.05).

CONCLUSION

Compared with HIIT alone, HIIT with BFR can better improve the body-fat level and glucose metabolism. HIIT with BFR in the interval phase better reduces the abdominal visceral-fat level than in the exercise phase, which may be due to the increase in lipolytic hormone level caused by the higher physiological load.