High-load Resistance Training Research Articles

Effects of Blood Flow Restriction Training on Muscle Strength and Hypertrophy in Untrained Males: A Systematic Review and Meta-Analysis Based on a Comparison with High-Load Resistance Training

Effects of Blood Flow Restriction Training on Muscle Strength and Hypertrophy in Untrained Males: A Systematic Review and Meta-Analysis Based on a Comparison with High-Load Resistance Training

Acute Effects of Transcranial Direct Current Stimulation Combined with High-Load Resistance Exercises on Repetitive Vertical Jump Performance and EEG Characteristics in Healthy Men.

Transcranial direct current stimulation (tDCS) is a non-invasive technique known to enhance athletic performance metrics such as vertical jump and lower limb strength. However, it remains unclear whether combining tDCS with the post-activation effects of high-load resistance training can further improve lower limb performance. This study investigated the synergistic effects of tDCS and high-load resistance training, using electroencephalography to explore changes in the motor cortex and vertical jump dynamics. Four experiments were conducted involving 29 participants. Each experiment included tDCS, high-load resistance training, tDCS combined with high-load resistance training, and a control condition. During the tDCS session, participants received 20 min of central stimulation using a Halo Sport 2 headset, while the high-load resistance training session comprised five repetitions of a 90% one-repetition maximum weighted half squat. No intervention was administered in the control group. Electroencephalography tests were conducted before and after each intervention, along with the vertical jump test. The combination of tDCS and high-load resistance training significantly increased jump height (p < 0.05) compared to tDCS or high-load resistance training alone. As for electroencephalography power, tDCS combined with high-load resistance training significantly impacted the percentage of α-wave power in the frontal lobe area (F3) of the left hemisphere (F = 6.33, p < 0.05). In the temporal lobe area (T3) of the left hemisphere, tDCS combined with high-load resistance training showed a significant interaction effect (F = 6.33, p < 0.05). For β-wave power, tDCS showed a significant main effect in the frontal pole area (Fp1) of the left hemisphere (F = 17.65, p < 0.01). In the frontal lobe area (F3) of the left hemisphere, tDCS combined with high-load resistance training showed a significant interaction effect (F = 7.53, p < 0.05). The tDCS combined with high-load resistance training intervention also resulted in higher β-wave power in the parietal lobe area (P4) and the temporal lobe area (T4) (p < 0.05). The findings suggest that combining transcranial direct current stimulation (tDCS) and high-load resistance training significantly enhances vertical jump performance compared to either intervention alone. This improvement is associated with changes in the α-wave and β-wave power in specific brain regions, such as the frontal and temporal lobes. Further research is needed to explore the mechanisms and long-term effects of this combined intervention.

Comparison of Metabolic, Ionic, and Electrolyte Responses to Exhaustive Low-Load Strength Training With and Without Blood Flow Restriction and High-Load Resistance Training.

Low-load blood-flow-restriction resistance training (LL-BFR-RT) is gaining popularity, but its physiological effects remain unclear. This study aimed to compare LL-BFR-RT with low-load resistance exercise (LL-RT) and high-load resistance exercise (HL-RT) on metabolism, electrolytes, and ions in the lower extremities by invasive catheter measurements, which are crucial for risk assessment. Ten healthy men (27.6 ± 6.4 years) completed three trials of knee-extensor exercises with LL-RT (30% 1RM), LL-BFR-RT (30% 1RM, 50% limb occlusion pressure), and HL-RT (75% 1RM). The exercise protocol consisted of four sets to voluntary muscle failure with 1 min of rest between sets. Blood gas analysis was collected before, during, and after each trial through intravenous catheters at the exercising leg. LL-BFR-RT had lower total workload (1274 ± 237 kg, mean ± SD) compared to LL-RT (1745 ± 604 kg), and HL-RT (1847 ± 367 kg, p < 0.01), with no difference between LL-RT and HL-RT. Pain perception did not differ significantly. Exercise-induced drop in oxygen partial pressure, lactate accumulation and electrolyte shifts (with increased [K+]) occurred during under all conditions (p < 0.001). Creatine kinase and lactate dehydrogenase increased significantly 24- and 48-h postexercise under all three conditions (p < 0.001). This study, using invasive catheter measurements, found no significant differences in metabolic, ionic, and electrolyte responses among LL-BFR-RT, LL-RT, and HL-RT when exercised to voluntary muscular failure. LL-BFR-RT reduced time to failure without specific physiological responses.

Mitigating disuse-induced skeletal muscle atrophy in ageing: Resistance exercise as a critical countermeasure.

The gradual deterioration of physiological systems with ageing makes it difficult to maintain skeletal muscle mass (sarcopenia), at least partly due to the presence of 'anabolic resistance', resulting in muscle loss. Sarcopenia can be transiently but markedly accelerated through periods of muscle disuse-induced (i.e., unloading) atrophy due to reduced physical activity, sickness, immobilisation or hospitalisation. Periods of disuse are detrimental to older adults' overall quality of life and substantially increase their risk of falls, physical and social dependence, and early mortality. Disuse events induce skeletal muscle atrophy through various mechanisms, including anabolic resistance, inflammation, disturbed proteostasis and mitochondrial dysfunction, all of which tip the scales in favour of a negative net protein balance and subsequent muscle loss. Concerningly, recovery from disuse atrophy is more difficult for older adults than their younger counterparts. Resistance training (RT) is a potent anabolic stimulus that can robustly stimulate muscle protein synthesis and mitigate muscle losses in older adults when implemented before, during and following unloading. RT may take the form of traditional weightlifting-focused RT, bodyweight training and lower- and higher-load RT. When combined with sufficient dietary protein, RT can accelerate older adults' recovery from a disuse event, mitigate frailty and improve mobility; however, few older adults regularly participate in RT. A feasible and practical approach to improving the accessibility and acceptability of RT is through the use of resistance bands. Moving forward, RT must be prescribed to older adults to mitigate the negative consequences of disuse atrophy.

Unilateral high-load resistance training induced a similar cross-education of strength between the dominant and non-dominant arm

ABSTRACT It was previously hypothesized that the cross-education of strength is asymmetrical, where a greater transfer of strength is observed from the dominant to the non-dominant limb. The purpose of this study was to examine if the magnitude of cross-education of strength differed between dominant and non-dominant limbs following unilateral high-load resistance training. One hundred and twenty-two participants were randomized to one of the three groups: 1) training on the dominant arm (D-Only), 2) training on the non-dominant arm (ND-Only) and 3) a time-matched non-exercise control (Control). The training groups completed 6 weeks (18 sessions) of unilateral elbow flexion exercise. Each training session started with one-repetition maximum (1RM) training (≤ five attempts), followed by four sets of high-load exercise (i.e. 8–12RM). Strength changes of the untrained arm were compared between groups. Changes in the strength of the untrained arm were greater in D-Only (1.5 kg) and ND-Only (1.3 kg) compared to Control (−0.2 kg), without differences between D-Only and ND-Only. Unilateral resistance training increased strength in the opposite untrained arm, and the magnitude of this effect was similar regardless of which arm was trained. However, there is still considerable uncertainty on this topic and additional research is warranted to confirm the current findings.

Blood Flow Restriction Exercise as a Novel Conservative Standard in Patients with Knee Osteoarthritis—A Narrative Review

Knee osteoarthritis is a prevalent joint disease affecting millions of individuals globally. While total knee arthroplasty is an effective treatment for advanced stages of KOA, it may not be suitable for earlier stages or younger patients. Supervised exercise therapy has proven to be the first-line treatment of preference in tackling pain and disability caused by KOA. However, the high intensities required to induce positive muscle adaptations are not indicated in this population, as this is often accompanied by pain, discomfort, and frustration, leaving low-load resistance training as the only feasible method of treatment. Recently, the use of blood flow restriction training has begun to emerge as a substitute for high-load resistance training. With BFRT, a cuff is applied around the proximal aspect of the affected limb, causing partial arterial and full venous occlusion, thereby inducing localized hypoxia and the accumulation of metabolites, mimicking the effects of high-load resistance training, albeit with low loads. Consequently, BFRT might offer a suitable and more effective alternative for KOA patients who are not (yet) eligible for TKA compared to traditional exercise therapy. This review aims to summarize the current evidence as regards the application of Blood Flow Restriction in exercise therapy for knee osteoarthritis patients, with particular consideration of the underlying mechanisms and its safety, as well as general guidelines for practical implementation in clinical practice. In doing so, this narrative review aims to create a framework for translating from theory into practice.

Hypertrophic effects of low-load blood flow restriction training with different repetition schemes: a systematic review and meta-analysis

Objective This systematic review and meta-analysis analyzed the effect of low-load resistance training (LL-RT) with blood flow restriction (BFR) versus high-load resistance training (HL-RT) on muscle hypertrophy focusing on the repetition scheme adopted. Methods Four databases were searched to identify randomized controlled trials that compared the effect of LL-RT with BFR versus HL-RT on muscle hypertrophy. Standardized mean differences (SMD) were pooled in a random effects meta-analysis. Results The overall analysis did not demonstrate significant differences between conditions (SMD = 0.046; p = 0.14). A similar result was observed when we separately analyzed studies that used sets to momentary muscle failure (SMD = 0.033; p = 0.520), sets of 15 repetitions (SMD = 0.005; p = 0.937) and a fixed repetition scheme composed of 75 repetitions (SMD = 0.088; p = 0.177). The analysis considering body region indicates no difference in lower limb exercise between HL-RT and LL-RT with BFR (SMD = 0.00066; p = 0.795) while upper limb exercise favors HL-RT (SMD = 0.231; p = 0.005). Conclusion LL-RT with BFR elicits muscle hypertrophy similar to HL-RT regardless of the employed repetition scheme, although there appears to be a small beneficial effect in favor of HL-RT in upper limb exercise.

Effect of open vs. closed kinetic chain exercises in ACL rehabilitation on knee joint pain, laxity, extensor muscles strength, and function: a systematic review with meta-analysis.

PROSPERO [CRD42023475230].

Blood Flow Restriction Therapy After Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACLR) rehabilitation necessitates restoration of quadriceps strength to minimize reinjury and optimize return to sport (RTS). Patients recovering from ACLR are limited by pain and activity restrictions, resulting in quadriceps muscle atrophy. Blood flow restriction (BFR) therapy involves performing exercises while a specialized blood pressure cuff is applied to the proximal aspect of the operative extremity and inflated to 40% to 90% of the arterial occlusion pressure, as determined using Doppler ultrasonography. BFR is theorized to induce an anaerobic environment and metabolic stress during exercise, promoting muscle hypertrophy and strength gains. Although the physiological mechanism has not been fully elucidated, it is theorized that BFR combined with low-load resistance training could yield muscle adaptations comparable to those of high-load resistance training. For ACLR patients with pain and restrictions precluding high-intensity strength training, incorporation of BFR into postoperative rehabilitation protocols could help mitigate quadriceps weakness and promote RTS. Randomized controlled trials report a prolonged, dose-dependent relation between BFR use and quadriceps and hamstring strength gains, improved bone and muscle mass, and earlier RTS, whereas other studies report no significant difference in quadriceps size, strength, or patient satisfaction compared with controls. Furthermore, although generally considered safe, there are rare reports of associated adverse events such as rhabdomyolysis, and BFR should be avoided in patients with a history of thromboembolic disease or peripheral vasculopathy. The literature examining BFR after ACLR is heterogeneous; lacks standardization; and contains broad variation in reported cuff pressures, as well as timing and duration of BFR use, among protocols. Although the use of BFR after ACLR shows promise, further study is necessary to elucidate the efficacy, safety, and optimal protocols.

Intermittent blood flow restriction with low-load resistance training for older adults with knee osteoarthritis: a randomized, controlled, non-inferiority trial protocol

BackgroundKnee osteoarthritis (KOA) is a chronic musculoskeletal disorder characterized by pain and functional impairment. Blood flow restriction (BFR) with low-load resistance training (LLRT) demonstrates a similar improvement in clinical outcomes to high-load resistance training (HLRT) in treating KOA. It has not been established whether intermittent blood flow restriction (iBFR) with LLRT can lead to clinical outcomes that are comparable to those produced by continuous blood flow restriction (cBFR) with LLRT and HLRT. The aim of the proposed study is to evaluate the efficacy of iBFR with LLRT on pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), muscle strength, muscle mass, physical function, perceptions of discomfort and effort, and adherence in KOA patients.MethodsThis is a three-arm, non-inferiority, randomized controlled trial utilizing blinded assessors. Two hundred thirteen participants will be randomly allocated to one of the following three groups: iBFR group—receiving 4 months of LLRT with iBFR, twice weekly (n = 71); cBFR group—receiving 4 months of LLRT with cBFR, twice weekly (n = 71); or HLRT group—receiving 4 months of HLRT without BFR, twice weekly (n = 71). The primary outcome is pain. The secondary outcomes include the WOMAC, muscle strength, muscle mass, physical function, perceptions of discomfort and effort, and adherence. Pain and WOMAC will be measured at the baseline and 4 and 12 months after randomizations. Muscle strength, muscle mass, and physical function will be measured at the baseline and 4 months after randomizations. The perceptions of discomfort and effort will be measured during the first and final sessions.DiscussionBFR with LLRT has a similar improvement in clinical outcomes as HLRT. However, cBFR may cause elevated ratings of perceived exertion and local discomfort, compromising patient tolerability and treatment adherence. If iBFR with LLRT could produce improvement in clinical outcomes analogous to those of HLRT and iBFR with LLRT, it could be considered an alternative approach for treating patients with KOA.Trial registrationChinese Clinical Trial Registry ChiCTR2300072820. Registered on June 26, 2023.

Comparison of resistance training using barbell half squats and trap bar deadlifts on maximal strength, power performance, and lean mass in recreationally active females: an eight-week randomised trial

BackgroundThe aim of this study was to investigate the effect of high load resistance training using barbell half squats compared with trap bar deadlifts on maximal strength, power performance, and lean mass in recreationally active females.MethodsTwenty-two recreationally active female participants (age: 26.9 ± 7.7 yrs.; height: 166.0 ± 5.1 cm; weight: 68.6 ± 9.9 kg) were randomly assigned to either a barbell half squat group (SG: n = 10) or trap bar deadlift group (DG: n = 12). Training consisted of twice-weekly sessions for eight weeks. Both groups completed one-repetition maximum (1RM) testing for both barbell half squat and trap bar deadlift groups. Countermovement jump (CMJ) and sprint performance were also assessed. Total body (TBLM) and leg lean mass (LLM) were measured with dual-energy x-ray absorptiometry. Between-group differences were analysed using analysis of covariance.ResultsSG tended to improve 1RM half squat (21.0 ± 11.5 kg vs. 13.1 ± 7.5 kg) more than DG (mean difference (MD): 8.0 kg, 95% CI: -0.36 – 16.3 kg). A similar pattern in favour of DG (18.4 ± 11.2 vs. 11.7 ± 8.1 kg) compared to SG was observed (MD: 6.5 kg, 95% CI: -2.5 – 15.6 kg). No between-group differences for sprint, jump or lean body mass changes was observed. For groups combined, the following changes in CMJ (2.0 ± 2.4 cm), 5-m sprint (-0.020 ± 0.039 s), 15-m sprint (-0.055 ± 0.230 s), TBLM (0.84 ± 1.12 kg), and LLM (0.27 ± 0.59 kg) was observed.ConclusionsAn exercise intervention consisting of half squats or trap bar deadlift were associated with improved muscle strength, power, and lean mass. Our findings suggests that in recreationally active females, exercise selection is less of a concern provided that heavy loads are applied, and relevant muscle groups are targeted.

Large inter-individual variability in force-velocity profile changes in response to acute high-load resistance training.

While the acute effects of high-load resistance training on the force generating capacity of muscles have been widely examined, limited data exist on the relationship with the force-velocity profile (FV). Evidence suggests high sensitivity of the vertical FV profile to monitor changes in the muscle's mechanical properties according to the type of the exercise protocol. However, the interpretation of the findings seems not as straightforward. Therefore, the purpose of this study was to examine the effects of a high-load resistance training protocol on the muscle's mechanical properties during loaded jumps and on the vertical force-velocity profile (FV) in relation to maximal strength. 29 resistance-trained male (mean age±SD: 35.4 ± 7.8 years) and 29 female athletes (mean age±SD: 32.5 ± 7.0 years) participated in the study. Five-repetition maximum (5RM) in back squat, unloaded countermovement jump (CMJ) and FV profile were assessed. Loaded jumps were performed against 25, 50, 75, and 100 percent of body mass. Participants performed exercise protocols corresponding to their 5RM. Immediately after, unloaded CMJ and FV profile measurements were repeated. A significant decrease in CMJ height (∼5-6%) and in average power (∼4%) was recorded for both men and women. The FV profile did not change after the exercise protocol; however, there was a significant decrease in theoretical maximal power (from 4 to 5%) and in theoretical maximal velocity (∼3%). Maximal strength was not associated with the changes in FV profile. Findings suggest that an acute high-load exercise decreased vertical jump performance and maximal power output, but without a concomitant change in FV profile. The large interindividual variability in FV measures indicates a less straightforward connection of the applied exercise with the acute response in the FV profile, highlighting the complexity of the FV profile to monitor changes in response to an acute training load.

THE EFFECTS OF MODERATE TO HIGH-LOAD RESISTANCE TRAINING WITH BLOOD FLOW RESTRICTION IN HEALTHY ADULTS: A SYSTEMATIC REVIEW

INTRODUCTION AND AIMS Low-load resistance training (RT) with blood flow restriction (BFR; 20–40% of 1-repetition maximum [1RM]) increases muscle mass and strength comparably to unrestricted high-load RT. As healthy populations are not limited to low-loads, some researchers have also examined whether the adaptations to high-load RT could be enhanced with BFR, though results are inconsistent. Therefore, we conducted a systematic review to investigate whether moderate to high-load resistance training (M-HL RT) with BFR increases muscle mass or strength more than the equivalent training without BFR. METHODS Studies involving M-HL RT (≥60% 1RM) with BFR applied during exercise sets or rest intervals were included. The following databases were searched: PubMed, Web of Science, Scopus, ScienceDirect, ProQuest Central, and Google Scholar. Two researchers independently screened the titles and abstracts for eligibility based on the inclusion and exclusion criteria. The full texts of included studies were then independently screened by two researchers. Conflicts were resolved by a third researcher. Following screening, study and participant characteristics, intervention protocol for each group and outcome measures were extracted for each included study. RESULT Ten studies met the criteria for inclusion in this review. All included studies measured muscle strength, with only three reporting greater strength increases after M-HL RT with BFR compared to equivalent training without BFR. Five studies assessed muscle mass, with four reporting similar increases after M-HL RT with and without BFR. One observed a smaller increase in mass after M-HL RT with BFR than without. CONCLUSION Most studies did not observe additional benefit of applying BFR during M-HL RT for muscle strength or mass. Studies which did report benefits of BFR may be limited by methodological issues, impacting the applicability of their findings. Overall, this review does not support using BFR during M-HL RT for additional improvements in muscle strength or mass.

Comparison of Blood Flow Restriction Interventions to Standard Rehabilitation After an Anterior Cruciate Ligament Injury: A Systematic Review.

Blood flow restriction training (BFR-t) data are heterogeneous. It is unclear whether rehabilitation with BFR-t after an anterior cruciate ligament (ACL) injury is more effective in improving muscle strength and muscle size than standard rehabilitation. To review outcomes after an ACL injury and subsequent reconstruction in studies comparing rehabilitation with and without BFR-t. Systematic review. Level of evidence, 3. A search of English-language human clinical studies published in the past 20 years (2002-2022) was carried out in 5 health sciences databases, involving participants aged 18-65 undergoing rehabilitation for an ACL injury. Outcomes associated with muscle strength, muscle size, and knee-specific patient-reported outcome measures (PROMs) were extracted from studies meeting inclusion criteria and compared. The literature search identified 279 studies, of which 5 met the selection criteria. Two studies suggested that BFR-t rehabilitation after an ACL injury improved knee or thigh muscle strength and muscle size compared with rehabilitation consisting of comparable and higher load resistance training, with two studies suggesting the opposite. The single study measuring PROMs showed improvement compared to traditional rehabilitation, with no difference in muscle strength or size. BFR-t after an ACL injury seems to benefit muscle strength, muscle size, and PROM scores compared with standard rehabilitation alone. However, only 1 large study included all these outcomes, which has yet to be replicated in other settings. Further studies utilizing similar methods with a common set of outcome measures are required to confirm the effects of BFR-t on ACL rehabilitation.

High-Volume Resistance Training Improves Double-Poling Peak Oxygen Uptake in Youth Elite Cross-Country Skiers and Biathletes: A Pilot Study

A total of nineteen elite youth cross-country skiers (16 ± 2 years) were divided into three groups: a low-load group (LL, n = 6) performing 15–20 repetitions per exercise, a high-load group (HL, n = 9) executing 6–12 repetitions, and a control group (CON, n = 4) exclusively engaging in endurance training. Testing included 1RM in upper-body exercises, VO2max running tests, and double-poling (DP) ergometer exhaustion and sprint tests to determine peak oxygen uptake (VO2peak-DP) and peak power (PP). The results indicated that HL and LL showed significant increases in VO2peak-DP, both in absolute values (d = −1.2 and −1.2, p &lt; 0.05) and when normalized to body mass (d = 0.93 and 1.3, p &lt; 0.05). Although there were no group*time effects for VO2peak-DP, PP during DP tests to exhaustion increased in both HL (d = −1.6, p &lt; 0.05) and LL (d = 1.4, p &lt; 0.05) compared to CON. Standardized to body mass, only HL showed significant improvements in PP during the sprint test (d = 1.7, p &lt; 0.05). During the sprint test, both absolute and body-mass-normalized peak power increased only in the high-load group (d = −1.0 and 0.93, p &lt; 0.05). In conclusion, high-load resistance training resulted in the greatest improvements in strength, DP performance, and VO2peak-DP, indicating a dose–response relationship to the load magnitude of resistance training.

Low- and high-load resistance training exercise to volitional fatigue generate exercise-induced appetite suppression

Research on exercise-induced appetite suppression often does not include resistance training (RT) exercise and only compared matched volumes. PurposeTo compare the effects of low-load and high-load RT exercise completed to volitional fatigue on appetite-regulation. Methods11 resistance-trained males (24 ± 2 y) completed 3 sessions in a crossover experimental design: 1) control (CTRL); 2) RT exercise at 30% 1-repetition maximum (RM); and 3) RT exercise at 90% 1-RM. RT sessions consisted of 3 sets of 5 exercises completed to volitional fatigue. Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 60-, and 120-min post-exercise. Energy intake was recorded the day before, of, and after each session. ResultsLactate was elevated following both 30% (0-, 60-, 120-min post-exercise) and 90% (0-, 60-min post-exercise; P < 0.001, d > 3.92) versus CTRL, with 30% greater than 90% (0-min post-exercise; P = 0.011, d = 1.14). Acylated ghrelin was suppressed by 30% (P < 0.007, d > 1.22) and 90% (P < 0.028, d > 0.096) post-exercise versus CTRL, and 30% suppressed concentrations versus 90% (60-min post-exercise; P = 0.032, d = 0.95). There was no effect on PYY (P > 0.171, ηp2 <0.149) though GLP-1 was greater at 60-min post-exercise in 90% (P = 0.052, d = 0.86) versus CTRL. Overall appetite was suppressed 0-min post-exercise following 30% and 90% versus CTRL (P < 0.013, d > 1.10) with no other differences (P > 0.279, d < 0.56). There were no differences in energy intake (P > 0.101, ηp2 <0.319). ConclusionsRT at low- and high-loads to volitional fatigue induced appetite suppression coinciding with changes in acylated ghrelin though limited effects on anorexigenic hormones or free-living energy intake were present.

Effects of low-load resistance training with blood flow restriction on muscle fiber myofibrillar and extracellular area.

Blood flow restriction applied during low-load resistance training (LL-BFR) induces a similar increase in the cross-sectional area of muscle fibers (fCSA) compared to traditional high-load resistance training (HL-RT). However, it is unclear whether LL-BFR leads to differential changes in myofibrillar spacing in muscle fibers and/or extracellular area compared to HL-RT. Therefore, this study aimed to investigate whether the hypertrophy of type I and II fibers induced by LL-BFR or HL-RT is accompanied by differential changes in myofibrillar and non-myofibrillar areas. In addition, we examined if extracellular spacing was differentially affected between these two training protocols. Twenty recreationally active participants were assigned to LL-BFR or HL-RT groups and underwent a 6-week training program. Muscle biopsies were taken before and after the training period. The fCSA of type I and II fibers, the area occupied by myofibrillar and non-myofibrillar components, and extracellular spacing were analyzed using immunohistochemistry techniques. Despite the significant increase in type II and mean (type I + II) fCSA (p < 0.05), there were no significant changes in the proportionality of the myofibrillar and non-myofibrillar areas [∼86% and ∼14%, respectively (p > 0.05)], indicating that initial adaptations to LL-BFR are primarily characterized by conventional hypertrophy rather than disproportionate non-myofibrillar expansion. Additionally, extracellular spacing was not significantly altered between protocols. In summary, our study reveals that LL-BFR, like HL-RT, induces skeletal muscle hypertrophy with proportional changes in the areas occupied by myofibrillar, non-myofibrillar, and extracellular components.

Effectiveness of High Load Plantar Fascia Resistance Training among Athletes with Plantar Fasciitis

Background: Plantar fasciitis is a common condition characterized by pain and inflammation in the plantar fascia,a thick band of tissue that runs along the bottom of the feet, connecting the heel to the toes. It is particularlyprevalent among athletes who engage in activities that involve repetitive impact, such as running, jumping.Athletes with plantar fasciitis often undergo a structured rehabilitation program that incorporates high loadresistance training alongside other interventions such as stretching, massage, orthotic devices, and modificationsin training and footwear.Purpose: To compare the effectiveness of High Load Plantar Fascia Resistance Training with ultrasound andIntrinsic Muscle strengthening with ultrasound among athletes with Plantar Fasciitis.Materials and Methods: Total of 60 subjects were selected from Sri Sai Ortho General Clinic based on the selectioncriteria and randomly divided into two groups; High load plantar fascia resistance training (HLST) with ultrasound(n=30) and Intrinsic muscle strengthening with ultrasound (n=30). The subjects were assessed for pain intensityusing NPRS and using LEFS, for pre and post-test values. The interventions were given for 2 weeks. Study period: November 2022 to March 2023Result: The result of the study revealed that both exercises are effective but (HLST) with ultrasound was moreeffective and significant in terms of decreasing pain and improving functional mobility.Conclusion: Hence the study concludes that HLST was more effective in managing plantar fasciitis in terms ofboth relieving pain as well as functional mobility among athletes with plantar fasciitis.

Effects of blood-flow restricted exercise versus conventional resistance training in musculoskeletal disorders—a systematic review and meta-analysis

ObjectiveTo compare the effect of low-load blood flow restricted resistance training (BFR-RT) versus high-load resistance training (HL-RT) on muscle strength, muscle mass, physical function, patient-reported outcomes, and adherence to training in clinical musculoskeletal populations.Data sourcesWeb of Science, Cochrane Central, Medline, Embase, SportDiscus was searched on the 30th May 2022.Review methodsThis study was conducted as a systematic review and meta-analysis. Randomized Controlled Trials (RCTs) were included if they (i) included patients, (ii) comprised of a BFR-RT intervention protocol and a group who performed HL-RT (≥ 70%1RM) for at least eight exercise sessions, and (iii) involved at least 1 exercise that targeted the lower limbs. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The meta-analyses were performed using a random effects model with an adjustment to the confidence interval.ResultsSeven RCTs comprising 303 participants (BFR-RT: n = 151; HL-RT: n = 152) were identified. HL-RT and BFR-RT showed similar gains in dynamic (1-10RM) knee extensor strength and leg press strength, quadriceps cross sectional area, sit-to-stand performance, and patient reported pain and function. There was a moderate effect favoring BFR-RT for increasing maximal isometric knee extensor strength. The grading of certainty in evidence was low-to-very low for all outcome variables.ConclusionThis systematic review and meta-analysis extends our current knowledge about BFR-RT and HL-RT as equally effective exercise methods for inducing gains in maximal muscle strength in healthy populations, by now also comprising patients suffering from various clinical musculoskeletal conditions. The certainty in the estimates was low-to-very low, prompting the inclusion of future higher-quality trials.Trial registrationPROSPERO ID (CRD42022337173). Registered June 18th 2022.

The effects of low-intensity resistance training with blood flow restriction versus traditional resistance exercise on lower extremity muscle strength and motor functionin ischemic stroke survivors: a randomized controlled trial

ABSTRACT Background Blood flow restriction (BFR) training can temporarily reduce cortical GABA concentrations and increase the size of motor volleys to deafferented muscles, which can promote motor recovery in stroke survivors. Objective To determine the effect of low-intensity resistance training with BFR (LIRT-BFR) on lower extremity muscle strength, balance, functional mobility, walking capacity, gait speed, anxiety, and depression in stroke survivors and to compare the results with high-intensity resistance training (HIRT). Method It was a two-arm, single-blinded, randomized controlled trial in which 32 ischemic stroke participants were randomly allocated to LIRT-BFR or HIRT group. The LIRT-BFR group received low load resistance training (40% of 1-Repetition Maximum (1-RM)) with BFR, whereas HIRT group received high load resistance training (80% of 1-RM). The 6-Minute Walk Test (6-MWT), five-time sit-to-stand test (5TSTST), Timed Up and Go (TUG) test, and Barthel index were the primary outcome measures. The secondary outcome measures included gait speed (m/s), stride length (cm), cadence (steps/min), and Hospital Anxiety and Depression. Results All the primary and secondary outcome measures were significantly improved in both groups (p < 0.05). The LIRT-BFR group showed a slightly greater, but non-significant, improvement as compared to the HIRT group in terms of mean change observed in 6-MWT (81 m vs 62 m), 5TSTST (−5.27 vs −4.81), gait speed (0.19 vs 0.12), stride length (18 vs 13), and cadence (8 vs 6). No adverse event was reported. Conclusion LIRT-BFR produced a significant improvement in muscle strength, balance, walking capacity, and anxiety and depression in ischemic stroke patients, and the improvement are comparable to HIRT. Clinical Trial Registration NCT05281679