Blood Flow Restriction Research Articles

Vascular Endhothelial Growth Factor levels in medium-intensity versus low-intensity exercise with blood flow restriction in elderly women

Introduction and Objective: The decrease in muscle mass in the elderly occurs due to molecular changes related to regeneration and degeneration of muscle proteins. Vascular Endothelial Growth Factor has a role in angiogenesis and increasing muscle mass through increasing the number and function of satellite cells. Elderly people have many limitations in strengthening exercises for increasing muscle mass, especially in safety and tolerance. Low-intensity strengthening exercise combined with blood flow restriction can be an alternative to increase muscle strength to the same extent as high-intensity strengthening exercise. This research aims to compare vascular endothelial growth factor levels between medium-intensity strengthening exercise and low-intensity strengthening exercise with blood flow restriction in elderly women. Methods: Twenty-two participants were trained for six weeks and underwent assessment at baseline, immediate after exercise, and at the end of training period. Participants were randomly divided into two groups: moderate intensity strengthening group (≥40-60% one-repetition maximum) and low intensity strengthening group (20-30% one-repetition maximum) with blood flow restriction using a cuff applied on the upper thigh at a restrictive pressure of 50 millimeters of mercury or 40% arterial occlusion pressure. Results and Conclusions: The low-intensity group showed significant acute increases in vascular endothelial growth factor levels, but no chronic effects were observed. The findings suggest that low-intensity strengthening exercises with blood flow restriction can effectively promote an acute increase in vascular endothelial growth factor levels in elderly women.

Effects of blood flow restriction training on cardiometabolic health and body composition in adults with overweight and obesity: a meta-analysis

ObjectiveThis meta-analysis aims to evaluate the effects of blood flow restriction (BFR) training on cardiometabolic health and body composition in adults with overweight and obesity.MethodFollowing PRISMA guidelines, a systematic search of PubMed (MEDLINE), EMBASE, Web of Science, Cochrane, and Scopus databases was conducted on 15 March 2024. Pooled effects for each outcome were summarized using Hedge’s g (g) through meta-analysis-based random effects models, and subgroup analyses were used to explore moderators.ResultsA total of 11 studies with 242 participants (Age:32.6 ± 3.6, BMI:27.2 ± 3.5) were included. Regarding cardiometabolic health, BFR training significantly reduced systolic blood pressure (g = 0.62 [0.08, 1.16], p = 0.02), while no significant differences were observed in maximal oxygen uptake (g = 0.48 [-0.21, 1.17], p = 0.17) or diastolic blood pressure (g = 0.31 [-0.22, 0.84], p = 0.25). Regarding body composition, BFR training significantly reduced body fat percentage (g = 0.30 [0.01, 0.58]; p = 0.04), while no significant differences (p > 0.05) were observed in body weight (g = 0.14 [-0.14, 0.42]), body mass index (g = 0.08 [-0.21, 0.38]), waist circumference (g = 0.13 [-0.28, 0.53]), or waist-to-hip ratio (g = 0.48 [-0.19, 1.15]). Subgroup analysis revealed no significant difference in improving systolic blood pressure (g = 0.57 [-0.10, 1.24] vs. g = 0.70 [-0.18, 1.59]) and body fat percentage (g = 0.20 [-0.20, 0.61] vs. g = 0.45 [-0.05, 0.95]) between BFR resistance training and BFR aerobic training. In all selected studies, the overall risk of bias was categorized as “some concern”. The certainty of evidence for the BFR outcomes was low.ConclusionBFR training shows promise in improving cardiometabolic health and body composition, indicating that it may serve as a beneficial, individualized exercise prescription for improving cardiovascular disease risk and fat loss in adults with excess body weight and obesity.Systematic Review Registration:https://archive.org/details/osf-registrations-uv6jx-v1.

Leg Blood Flow During Exercise with Blood Flow Restriction: Evidence for and Implications of Compensatory Cardiovascular Mechanisms.

Proximal limb cuff inflation to 40% arterial occlusion pressure (AOP) is assumed to reduce exercising leg perfusion, creating "blood flow restriction" (BFR). However, no study has validated this assumption. 18 healthy young participants (9F) performed two-legged knee flexion/extension exercise at 25% WRpeak with bilateral cuffs applied to the proximal thigh at 0% AOP (CTL), 20% AOP and 40% AOP. Leg blood flow (LBF; Doppler and echo ultrasound) and cardiac output (CO; finger photoplethysmography) were measured during rest and exercise. LBF values were doubled to account for both exercising legs. 20% and 40% AOP reduced exercising LBF in a dose-response manner (P<.01). However, the magnitude of the leg blood flow restriction by 40% AOP was progressively attenuated across the exercise bout (5-15s: 37%, 50-70s: 20%, 240-300s: 16%; P<.01) due to compensatory increases in leg vascular conductance (LVC) (P<.01). Between 5-15s of exercise, 40% AOP significantly reduced CO compared to CTL and 20% AOP (8.0 ± 1.3 vs. 8.4 ± 1.5 L/min, P<.001 and 8.5 ± 1.5, P<.001). By 240-300s, there were no significant differences in CO between cuff pressures (all P>.13). Pneumatic cuff inflation at 20% and 40% AOP reduces LBF in a dose-response manner, but this impairment was progressively attenuated across the exercise bout by an increase in LVC. Importantly, this compensatory response differed across participants, which may have implications for the degree of adaptations following BFR training. Furthermore, restoration of normal CO during BFR despite compromised limb perfusion suggests other tissue perfusion is increased as part of the response.

Blood Flow Restriction Training in the Rehabilitation of Hamstring Injuries

Blood flow restriction (BFR) training is a novel technique of assisted rehabilitation that has been of interest to an increasing number of scholars in recent years. BFR training shows promising applications in the rehabilitation of hamstring injuries. Currently, research indicates that low-load BFR training is a useful substitute for conventional high-load resistance training. The effectiveness of BFR training in the recovery process of hamstring injuries, however, has not received much research. This paper reviews all the recent relevant literature with the aim of exploring the current efficacy, potential mechanisms, and potential safety issues with the application of BFR training in the rehabilitation of hamstring injuries. There are still many controversial and unresolved issues in the field, such as the optimal protocol for BFR application to injured hamstrings, specific potential mechanisms, and safety considerations for BFR training. It is hoped that this paper will trigger the attention of more scholars to address these issues in future research.

Observing Changes in Motoneuron Characteristics Following Distorted Sensorimotor Input via Blood Flow Restriction.

Disruption of the blood supply to a limb in conjunction with active movement boosts muscle growth, aids in rehabilitation, and allows controlled exploration of the sensorimotor system. Yet, the underlying neuromechanical changes have not been observed in great detail. This study aims to report the acute neuromuscular effects of temporary blood flow restriction (BFR) through behavioral changes at the level of motor units (MUs) using high-density surface electromyography on the abductor digiti minimi muscle during 20 trapezoidal and sinusoidal isometric force tracking tasks (5 pre-BFR, 5 during BFR, and 10 post-BFR). Unsurprisingly, during BFR, reported discomfort levels increased significantly (ρ < 0.001) regardless of the task (+239% trapezoidal, +228% sinusoidal). However, BFR had very little impact on task tracking performance, though the reconstructed force derived from the underlying neural drive (smoothed cumulative spike train of MUs) deviated substantially during BFR (-40% in trapezoidal, -47% in sinusoidal). Regardless of the condition, the numbers of extracted MUs were consistent (20-26 in trapezoidal, 23-29 in sinusoidal). Interestingly, the inter-spike interval (ISI) of these units increased by 28% in trapezoidal and 24% in sinusoidal tasks during BFR, with ISI steadily returning to original values post-BFR. These results indicate that acute BFR transiently alters the active MU pool, and MU firing behavior, yet only slightly affects the resulting task performance. However, pre-BFR motor function is gradually restored after BFR release. These findings provide insights into the resulting effects of acute BFR administration and the complex response it elicits from the sensorimotor system.

Progress of the Exercise Therapy on Chronic Ankle Instability

This research delves into the effectiveness of various exercise therapies for Chronic Ankle Instability (CAI), a condition that frequently develops when initial ankle sprains are not adequately treated. CAI is characterized by repetitive sprains, joint instability, and reduced mobility, which can severely impact an individual's daily activities and sports performance. Different methods of rehabilitation, including muscle strengthening exercises, proprioceptive training, and balance improvement, were evaluated. The study emphasizes the advantages of combining traditional approaches such as resistance band exercises and newer techniques like blood flow restriction (BFR) training. These methods help enhance both strength and functionality in patients with CAI. Additionally, integrating proprioceptive exercises that focus on improving balance through unstable surface training has shown significant progress in restoring postural stability. Further, novel therapeutic interventions, including motor imagery, transcranial direct current stimulation (tDCS), and exergaming, demonstrate promising results in complementing traditional treatments. Ultimately, this review suggests a comprehensive rehabilitation plan that merges conventional and modern therapies to improve functional outcomes for individuals with CAI, though further research is necessary to optimize the combination of these therapies for long-term efficacy.

Patch-Wise Deep Learning Method for Intracranial Stenosis and Aneurysm Detection-the Tromsø Study

Intracranial atherosclerotic stenosis (ICAS) and intracranial aneurysms are prevalent conditions in the cerebrovascular system. ICAS causes a narrowing of the arterial lumen, thereby restricting blood flow, while aneurysms involve the ballooning of blood vessels. Both conditions can lead to severe outcomes, such as stroke or vessel rupture, which can be fatal. Early detection is crucial for effective intervention. In this study, we introduced a method that combines classical computer vision techniques with deep learning to detect intracranial aneurysms and ICAS in time-of-flight magnetic resonance angiography images. The process began with skull-stripping, followed by an affine transformation to align the images to a common atlas space. We then focused on the region of interest, including the circle of Willis, by cropping the relevant area. A segmentation algorithm was used to isolate the arteries, after which a patch-wise residual neural network was applied across the image. A voting mechanism was then employed to identify the presence of atrophies. Our method achieved accuracies of 76.5% for aneurysms and 82.4% for ICAS. Notably, when occlusions were not considered, the accuracy for ICAS detection improved to 85.7%. While the algorithm performed well for localized pathological findings, it was less effective at detecting occlusions, which involved long-range dependencies in the MRIs. This limitation was due to the architectural design of the patch-wise deep learning approach. Regardless, this can, in the future, be mitigated in a multi-scale patch-wise algorithm.

Muscle-specific neuromuscular responses during running with blood flow restriction.

The purpose of this investigation was to examine muscle excitation at maximal running capacity without blood flow restriction (BFR) relative to submaximal running bouts with BFR. Fourteen college-aged males randomly completed four, three-minute running bouts at 70, 80, and 90% of peak speed with BFR (70%BFR, 80%BFR, and 90%BFR) and without BFR at 100% of their peak speed (100%NOBFR). The surface electromyographic amplitudes of the vastus lateralis, rectus femoris, and vastus medialis muscles were assessed. Muscle excitation of the vastus lateralis was similar across most bouts; however, it was lower during the 70%BFR compared to 90%BFR (Meandiff =-4.67±- 0.22%; Bayesian 95% high-density interval [HDI]: - 7.07 to - 2.2) and 100%NOBFR (Meandiff =-2.94±- 0.27%; 95% HDI:-5.33 to-0.50) bouts. For the rectus femoris, muscle excitation largely increased across running speeds (70%BFR<80%BFR < 90%BFR; 90%BFR < 100%NOBFR). For the vastus medialis, muscle excitation was lower during the 70%BFR compared to 90%BFR (Meandiff =-8.15±- 0.28%; 95% HDI:-15.3 to-0.89). Submaximal running with BFR increased muscle excitation responses for the vastus lateralis and vastus medialis, such that muscle excitation was similar to 100%BFR, despite 10-20% reductions in running speed. The rectus femoris muscle, however, was not affected by BFR during the submaximal running bouts.

Impact of early and late morning supervised blood flow restriction training on body composition and skeletal muscle performance in older inactive adults

Impact of early and late morning supervised blood flow restriction training on body composition and skeletal muscle performance in older inactive adults

Salivary testosterone and cortisol responses to seven weeks of practical blood flow restriction training in collegiate American football players

Salivary testosterone and cortisol responses to seven weeks of practical blood flow restriction training in collegiate American football players

Blood flow restriction-enhanced platelet-rich plasma: A pilot randomised controlled trial protocol.

To assess platelet-rich plasma (PRP) changes in platelet and leucocyte count, insulin-like growth factor 1 (IGF-1), and interleukin 6 (IL-6) concentration after bilateral low-load knee extensions under blood flow restriction (BFR). The present randomised controlled trial protocol will include two groups: the intervention group, which will undergo bilateral knee extensions under BFR, and the control group, which will perform bilateral knee extensions without BFR. Participants will be randomly allocated in a 1:1 ratio. Twenty-two healthy individuals will be enrolled if the predefined inclusion criteria are met: (1) males, (2) ages 18-40, (3) Tegner activity level ≥5 and (4) with no musculoskeletal conditions that would interfere with exercise. Exclusion criteria include (1) individuals with systemic inflammatory diseases, (2) cardiovascular risk factors, (3) any blood dyscrasia, (4) Tegner Activity scale scores <5, (5) under nonsteroidal anti-inflammatory drugs and aspirin treatment within one week before testing or (6) that had previously performed exercises on the testing day. The participant will perform low-load bilateral knee extensions under BFR following a standard protocol of 30-15-15-15 repetitions of consecutive sets with 30-s rest intervals at 80% of limb occlusive pressure and 30% of 1-RM load. PRP platelet and leucocyte count, IGF-1 and IL-6 concentration measurements (via flow cytometry, chemiluminescence testing and immunochromatography, respectively) will be conducted before exercise and 10, 20 and 30 min after the intervention. The expected outcome is that the standard protocol of low-load bilateral knee extensions under BFR will increase the platelet and leucocyte count, IGF-1 and IL-6 in the PRP preparation. The current protocol allows the study of an enhanced PRP formulation for its potential implementation in multiple sports injuries.

Low-Intensity Resistance Exercise with Blood Flow Restriction Improves Balance in Elderly Women: A Comparative Study on the Lower Quarter Y-Balance Test

Introduction: Enhancing leg muscle strength in elderly could play a crucial role in reducing fall risk. A novel approach to enhance muscular strength involves the use of low-intensity resistance exercises in conjunction with blood flow restriction (BFR), as an alternative to high-intensity exercise. This study aimed to evaluate the effects of low-intensity strength exercise with BFR on lower quarter Y-balance test (LQ-YBT) performance, compare to moderate-intensity strength exercise in elderly female.Methods: The study employed a true experimental randomized design, assessing balance using the LQ-YBT in 26 elderly women over a six-week exercise period. Subjects were divided into two groups: one performing medium-intensity strengthening exercises (≥40-60% 1 RM (Repetition Maximum)) and another engaging in low-intensity strengthening exercises (20-30%1RM) with BFR. The BFR technique involved applying a cuff to the upper third of the thigh with a restrictive pressure of 50 mmHg or 40% Artery Occlusion Pressure, which was released during rest periods.Results: The moderate and BFR groups exhibited notable distinctions in all directions (anterior, posterolateral, posteromedial and composite) for both left and right legs (p&lt;0.001). The disparity in LQ-YBT values between groups was notable in the right anterior (p=0.017), right posterolateral (p&lt;0.001), right composite (p&lt;0.001), left anterior (p=0.007), and left composite (p=0.050) directions.Conclusions: This study showed that low-intensity resistance exercise with BFR for six weeks may yield superior improvements in the LQ-YBT for elderly women compared to moderate-intensity strengthening exercises

Effect of Blood Flow Restriction Resistance Training on Elbow Joint Muscle Strength

Blood flow restriction training combined with low-intensity resistance training is associated with increases in muscle strength and size. The effect of blood flow restriction resistance training on muscle strength at the elbow joint is unknown. The purpose of this systematic review was to explore the effects of blood flow restriction resistance training compared with traditional low or high-intensity resistance training on muscle strength at the elbow. Relevant literature from 3 databases was searched. Risk of bias was assessed using the PEDro scale. Eventually, 1502 literatures were retrieved, and 11 of these high-quality literatures were included in the review after screening out. blood flow restriction resistance training significantly increased elbow flexor and extensor muscle strength and muscle size. Blood flow restriction training combined with low-intensity resistance training was superior to low-intensity resistance training alone in terms of muscle strength and size during long-term training and achieved a similar level of traditional high-intensity resistance training, which was applicable during both isometric and isotonic training. It can be carried out in healthy adults or patients who are significantly weakened and unable to perform conventional strength training.

Acute Responses to Different Lifting Velocities During Squat Training With and Without Blood Flow Restriction.

Cornejo-Daza, PJ, Sánchez-Valdepeñas, J, Páez-Maldonado, J, Rodiles-Guerrero, L, Sánchez-Moreno, M, Gómez-Guerrero, G, León-Prados, JA, and Pareja-Blanco, F. Acute responses to different lifting velocities during squat training with and without blood flow restriction. J Strength Cond Res XX(X): 000-000, 2024-The aims of the research were to compare the acute mechanical, metabolic, neuromuscular, and muscle mechanical responses to different lifting velocities (maximal vs. half-maximal) under distinct blood flow conditions (free [FF] vs. restricted [BFR]) in full-squat (SQ). Twenty resistance-trained males performed 4 protocols that differed in the velocity at which loads were lifted (MaxV: maximal velocity vs. HalfV: half-maximal velocity) and in the blood flow condition (FF: free-flow vs. BFR: 50% of arterial occlusion pressure). The relative intensity (60% 1 repetition maximum), volume (3 sets of 8 repetitions), and resting time (2 minutes) were matched between protocols. Mean propulsive force (MPF), mean propulsive velocity (MPV), mean propulsive power (MPP), and electromyography (EMG) values were recorded for each repetition. Tensiomyography (TMG), blood lactate, countermovement jump (CMJ), maximal voluntary isometric contraction in 90° SQ, and performance with the load that elicited a 1-m·s-1 velocity at baseline measurements (V1-load) in SQ were assessed at pre-exercise and postexercise. The MaxV protocols showed significantly greater MPF, MPV, MPP, and EMG amplitude during the exercise than the HalfV protocols (velocity effect, p < 0.05). The FF protocols achieved higher MPF and MPP during exercise than BFR (BFR effect, p < 0.05). The BFR protocols induced greater blood lactate after exercise (BFR × time interaction, p = 0.02), along with higher postexercise impairments in mechanical performance (BFR × time interaction, p < 0.05). The MaxV protocols elicited superior performance and greater muscle activation during exercise. The BFR protocols resulted in lower force and power production during exercise and exhibited higher performance impairments and increased metabolic stress postexercise.

Blood flow restriction training with cross education for quadriceps muscle recovery after anterior cruciate ligament reconstruction: A prospective, randomized, controlled, single-blind clinical trial.

Recently, blood flow restriction (BFR) and cross education (CE) trainings are the options for quadriceps strength recovery after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to investigate the effects of CE combined with BFR on quadriceps strength and thickness after ACLR. Twenty-four male patients [(Age: 24.9 ± 6.3 years, body mass index: 24 ± 2.3 kg/m2) who had undergone ACLR with hamstring autograft were included. At 4 weeks after surgery, the patients were randomly divided into two groups (Group-1: CE + BFR, n = 13, Group-2: CE, n = 11). All patients had standardized rehabilitation for their reconstructed limb until 12 weeks postsurgery, and they all received CE training for uninjured limb at isokinetic system (quadriceps eccentric contraction, 60°/s 3-set 12-rep, 2-days in a week) during 8 weeks. Group 2 performed the same CE procedure with BFR. Quadriceps isometric strength was measured using an isokinetic dynamometer, while the thickness of quadriceps (rectus femoris, vastus lateralis, vastus medialis obliquus) and cross-sectional area of rectus femoris were evaluated using ultrasound pretraining (4th-week postsurgery) and posttraining (12th-week postsurgery). Analysis of variance was used for statistical analysis. Group-by-time interaction and the group main effect were not significant for any measured variables in both limbs (p > 0.05). There was a significant main effect of time observed for quadriceps strength and thickness in involved and uninvolved limbs (p < 0.001, p < 0.05, respectively). In Group 1, the limb symmetry index for quadriceps strength increased from 49.3% to 71.7%, while in Group 2, it increased from 50.9% to 75.2%. BFR training, adapted to CE eccentric strengthening, may not be effective for quadriceps muscle strength recovery after ACLR. Further investigations with varied training protocols are needed to research the impact of BFR on CE. Level II randomized controlled trial.

Effects of Different Blood Flow Restriction Training Modes on Body Composition and Maximal Strength of Untrained Individuals.

The objective of this study was to examine the impacts of absolute cuff pressure blood flow restriction (A-BFR) training and incremental cuff pressure blood flow restriction (I-BFR) training, under equal cuff pressures, on body composition and maximal strength among untrained adults. Additionally, we aimed to compare these effects with those observed in high-load resistance training (HL-RT). Thirty-three adults without prior professional sports or resistance training experience were recruited and randomly assigned to three groups (n = 11 per group) for an 8-week training program, held three times weekly. The A-BFR group trained with a 20% 1RM load and a cuff occlusion pressure set at 190 mmHg. The I-BFR group initiated training with an occlusion pressure of 160 mmHg, which incrementally increased by 20 mmHg every two weeks, with other conditions mirroring those of the A-BFR group. The HL-RT group trained with a 70% 1RM load. All three groups demonstrated a statistically significant improvement in lower-body maximal strength (p < 0.01), with no significant differences observed among the groups (p > 0.05). A notable increase in left-leg muscle mass was seen across all groups (p < 0.05). However, total muscle mass, right-leg muscle mass, fat-free mass, BMI, bone mineral density, and bone mineral content remained relatively unchanged (p > 0.05), with no significant differences among the groups (p > 0.05). Only the HL-RT group exhibited a significant increase in left-leg thigh circumference (p < 0.05), while right-leg thigh circumference remained stable (p > 0.05), with no significant intergroup differences (p > 0.05). While A-BFR and I-BFR did not yield statistically significant differences in overall training outcomes, A-BFR demonstrated a slightly stronger potential. A-BFR and I-BFR achieved comparable gains in muscle strength and improvements in body composition to those seen with HL-RT. However, HL-RT demonstrated more significant improvements in leg circumference.

Individual muscle hypertrophy in high-load resistance training with and without blood flow restriction: A near-infrared spectroscopy approach

ABSTRACT We aimed to compare individual hypertrophic responses to high-load resistance training (HL-RT) or high-load with blood flow restriction (HL-BFR). Furthermore, we investigated whether greater responsiveness to one of the protocols could be explained by acute changes in blood deoxyhemoglobin concentration (HHb) and total hemoglobin concentration (tHb) (proxy markers of metabolic stress). Ten untrained participants had their legs randomized into both HL-RT and HL-BFR and underwent 10 weeks of training. Muscle cross-sectional area (mCSA) was measured at baseline and post training, while HHb and tHb during the final session. Using a threshold of 2 × typical errors (3.24%) to compare protocols, five participants showed greater mCSA increases after HL-RT (16.44 ± 7.90%) compared to HL-BFR (10.74 ± 7.12%, p = 0.0054) and five did not respond better to HL-RT (8.95 ± 10.83%) compared to HL-BFR (13.33 ± 8.59%) (p = 0.3105). Additionally, HL-RT induced lower HHb (5855.78 ± 12905.99; p = 0.0101) and tHb (−43169.70 ± 37793.17; p = 0.0030) AUC values compared to HL-BFR (HHb: 39254.80 ± 27020.15; tHb: 46309.40 ± 31613.97). In conclusion, despite the higher levels of metabolic stress markers, most participants did not present greater muscle hypertrophy by combining blood flow restriction with HL-RT.

High-intensity interval training with blood-flow restriction enhances sprint and maximal aerobic power in male endurance athletes.

We investigated the concurrent impact of HIIT and blood-flow restriction (BFR) as a novel approach to further enhance maximal aerobic and anaerobic physiology and performances in trained athletes. In a randomized controlled trial, eighteen endurance-trained males (V ̇O2peak 65.6±5.1 ml.min-1.kg-1) included three sessions of HIIT per week (sets of 15-s efforts at 100% maximal aerobic power, interspersed by 15-s recovery) into their usual training for three weeks, either with restriction imposed on both lower limbs at 50-70% of arterial occlusion pressure (BFR group, n=10) or without (CTL group, n=8), and were tested for sprint and endurance exercise performance. The total mechanical work developed during a 30-sec Wingate test increased only in BFR (3.6%, P=0.02). During the Wingate, changes in near-infrared spectroscopy-derived vastus lateralis muscle oxygenation (Δ(deoxy[Hb+Mb]), % arterial occlusion) were attenuated after BFR training (-8.8%, P=0.04). The maximal aerobic power measured during an incremental cycling test increased only in BFR (4.5%, P=0.0004), but there was no change in V ̇O2peak among groups. Both groups improved 5-km cycling time trial performance, but BFR displayed a concomitant greater elevation in [H+] (11%, P=0.02). Changes in other blood variables (e.g., pH, lactate, bicarbonate and potassium ion concentration, hemoglobin) were not different between groups. Combining short-duration HIIT performed at 100% aerobic power with BFR elicited greater changes in sprint performance and maximal aerobic power in endurance athletes, associated with locomotor muscle metabolic adaptations but no meaningful effect on cardiorespiratory fitness.

Research Progress on the Intervention Effects of Different Exercise Forms on Risk Factors for Obesity-Related Cardiovascular Diseases

Obesity has become a major global health issue and is an independent risk factor for several cardiovascular risks. Exercise, as a therapeutic method, is commonly used to improve cardiovascular health in obese populations. This paper reviews and analyzes the effects of five different exercise forms on risk factors for obesity-related cardiovascular diseases: Moderate-Intensity Continuous Training (MICT), High-Intensity Interval Training (HIIT), Sprint Interval Training (SIT), aerobic combined with resistance training, and Blood Flow Restriction Training (BFR). The aim is to explore the similarities and differences in health benefits among these exercise forms for individuals with obesity. The review finds that MICT is notably effective in reducing cardiovascular disease risk factors and promoting cardiovascular health in obese individuals. In contrast, high-intensity interval exercises such as HIIT and SIT show even more significant improvements in cardiovascular health. This difference may be attributed to varying biological effects caused by different intensity levels and intervals, though the specific mechanisms require further clarification. Since increased skeletal muscle can enhance basal metabolic rate and positively impact the cardiovascular system, resistance training is often recommended in combination with aerobic training for better results. Additionally, BFR can achieve similar training effects under lower exercise loads, providing a safer training option for obese individuals. Future research should focus on the mechanisms by which different exercise forms affect specific cardiovascular disease risk factors and how to optimize exercise programs based on individual differences to enhance personalization and scientific validity of interventions.

Impact of Five Weeks of Strengthening Under Blood Flow Restriction (BFR) or Supplemental Oxygen Breathing (Normobaric Hyperoxia) on the Medial Gastrocnemius.

Background and Objectives: This study investigates the effects of a five-week training program on the medial gastrocnemius muscle, comparing two approaches: blood flow restriction (BFR) training and normobaric hyperoxia (oxygen supplementation). It evaluates three strengthening modalities (dynamic, isometric, and the 3/7 method) analyzing their impact on maximal voluntary contraction (MVC), muscle architecture, and perceived exertion. Methods: A total of 36 young healthy participants (21 females, 15 males) were randomized into six subgroups (n = 6 each) based on the type of contraction and oxygen condition. Training sessions (three per week) were conducted for five weeks at 30% of MVC. Measurements of MVC, muscle circumference, pennation angle, fascicle length, and perceived exertion were taken at baseline (T0), mid-protocol (T1), and post-protocol (T2). Results: All groups demonstrated significant increases in MVC after five weeks, with no notable differences between BFR and oxygen conditions. Structural changes were observed in specific subgroups: the BFR-isometric group showed increased calf circumference (p < 0.05), and the 3/7 groups exhibited significant fascicle length gains (p < 0.05). Perceived exertion was consistently higher in BFR groups compared to oxygen supplementation, particularly in dynamic exercises. Conclusions: Both BFR and oxygen supplementation are effective in enhancing strength with light loads, though they elicit different structural and perceptual responses. Oxygen supplementation may be more comfortable and less strenuous, offering a viable alternative for populations unable to tolerate BFR. Future research should focus on optimizing training parameters and exploring applications tailored to specific athletic or clinical contexts.