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Introduction: Blood flow restriction (BFR) is a relatively new rehabilitative technique and low‐load exercise combined with BFR (LL‐BFR) can increase muscle strength and muscle mass. However, it is currently unknown whether LL‐BFR causes muscle damage. Therefore, the aim of this study is to investigate the effects of LL‐BFR on muscle damage and provide recommendations for sports training and physical exercise. Materials and Methods: A systematic search was conducted using PubMed, Web of Science, Medline, Cochrane Library and Physiotherapy Evidence Database (PEDro) with a cut‐off of March 2022. Randomized controlled trials (RCTs) and English‐language studies were selected. Two independent assessors used the PEDro scoring scale to evaluate the methodological quality and risk of bias of the included studies. Results: Of the 2935 articles identified, 15 RCTs were included in this systematic review. Two studies demonstrated that LL‐BFR could induce muscle damage in healthy individuals; however, two studies presented contrasting findings in the short term. Four studies found that no muscle damage occurred after LL‐BFR in the long term. The remaining seven articles showed that it was unclear if LL‐BFR could cause muscle damage, regardless of whether these participants were trained or not. Conclusion: Although LL‐BFR may induce muscle damage within 1 week, it will help gain long‐term muscle strength and muscle hypertrophy. However, the lack of sufficient evidence on the effect of LL‐BFR on muscle damage in clinical practice warrants additional RCTs with large sample sizes in the future. [ABSTRACT FROM AUTHOR]

Exercise intolerance in patients with heart failure (HF) increases HF-associated readmission, and right ventricular (RV) contractile reserve assessed by low-load exercise stress echocardiography (ESE) is associated with exercise intolerance. This study investigated the impact of RV contractile reserve evaluated by low-load ESE on HF readmission. We prospectively examined 81 consecutive patients hospitalized for HF who underwent low-load ESE under a stabilized HF condition between May 2018 and September 2020. We performed a 25-W low-load ESE and defined RV contractile reserve as the increment in RV systolic velocity (RV s′). The primary outcome was hospital readmission. Incremental values of the change in RV s′ over a readmission risk (RR) score were analyzed using the receiver operating characteristic (ROC) area under the curve; internal validation using bootstrapping was performed. The association between RV contractile reserve and HF readmission was illustrated with the Kaplan-Meier curve. Eighteen (22 %) patients were readmitted due to worsening HF during the observation period (median 15.6 months). The cut-off value of 0.68 cm/s for the change in RV s′ to predict HF readmission with the ROC curve analysis indicated good sensitivity (100 %) and specificity (76.2 %). The discriminatory ability for HF readmission was significantly improved by adding the change in RV s′ to the RR score (p = 0.006), and the c-statistic using the bootstrap method was 0.92. The cumulative survival rate free of HF readmission was significantly lower in patients with reduced-RV contractile reserve (log-rank test, p < 0.001). The change in RV s′ during low-load exercise had an incremental prognostic value for predicting HF readmission. The results demonstrated the loss of RV contractile reserve assessed by low-load ESE was associated with HF readmission. [Display omitted] • Low-load exercise stress echocardiography is useful for heart failure patients. • Assessing right ventricular function during low-load exercise is important. • Right ventricular contractile reserve predicts heart failure readmission. [ABSTRACT FROM AUTHOR]

Introduction: Blood flow restriction exercise has proven to be an effective training method to promote neuromuscular adaptations, however, a consensus about the effect on other physiological and safety variables, such as cardiovascular responses, has yet to be reached. Purpose: The aim of this study was to compare the acute cardiovascular responses during and after three different resistance training protocols. Material & methods: Fifty-two participants (27.3±7 years; 177.6±11 cm; 72.2±13.7 kg) were randomly allocated into three groups: low-intensity exercise without (LI, n=13) and with blood flow restriction (LI-BFR, n=24), and highintensity exercise (HI, n=15). Participants from LI and LI-BFR groups performed four sets (1x30 + 3x15 reps) at 30% 1RM, while HI group performed four sets (1x30 with 30% 1RM + 3x10 reps with 75% 1RM) of dominantside plantar flexion exercise. For LI-BFR group, a cuff was placed under popliteal region and inflated at 30% of the individual's occlusion pressure (47.6 ± 19.8 mmHg). Results: Blood pressure (BP), heart rate (HR) and oxygen saturation (SpO2) were assessed at baseline, after each set and post-exercise. HR increases significantly during exercise across all protocols, with greater increases for HI group after 4th set (p<0.001; G=1.072) but without differences between groups. HI and LI-BFR protocols showed higher significant post-exercise hypotension and greater reduction in MAP (p<0.05) than LI group. RPP during exercise was different from HI to LI and LI-BFR (p<0.05). HI protocol reduced SpO2 during all sets of exercise (p<0.05). Conclusions: The results of this study indicate that LI-BFR promotes similar hypotensive response to HI, with equal or lower cardiovascular responses during exercise than traditional resistance training. [ABSTRACT FROM AUTHOR]

Abstract Aims Traditional criteria for heart transplantation by cardiopulmonary exercise testing (CPX) include peak oxygen uptake (VO2)

The Achilles tendon is one of the strongest and thickest tendons of the human body. Several studies have reported an immediate decrease in Achilles tendon thickness after a single bout of resistance training. However, the effects of blood flow restriction training on Achilles tendon thickness have not been investigated. The purpose of this study was to investigate the acute effects of different regimens of resistance training on Achilles tendon thickness. Fiftytwo participants (27.3 ± 7 years; 177.6 ± 11 cm; 72.2 ± 13.7 kg) were randomly allocated into one of the three groups: low-intensity exercise without (LI, n = 13) and with blood flow restriction (LI-BFR, n = 24), and high-intensity exercise (HI, n = 15). Participants from LI and LI-BFR groups performed four sets (1 x 30 + 3 x 15 reps) at 30% 1RM, while the HI group performed four sets (1 x 30 with 30% 1RM + 3 x 10 reps with 75% 1RM). All groups performed a plantar flexion exercise. For the LI-BFR group, a blood pressure cuff was placed on the dominant calf and inflated at 30% of the individual´s occlusion pressure (47.6 ± 19.8 mmHg). Sonographic images of Achilles tendon thickness were taken at pre, immediately after, 60 min and 24 h following acute bouts of exercise. Achilles tendon thickness was significantly reduced immediately after, 60 min and 24 h post-LI-BFR exercise (pre: 4.4 ± 0.4 mm vs. IA: 3.8 ± 0.4 mm vs. 60 min: 3.7 ± 0.3 mm vs. 24 h: 4.1 ± 0.3 mm; p < 0.001), whereas Achilles tendon thickness was unchanged for HI and LI groups (p > 0.05). These results suggest that blood flow restriction training may be an effective strategy to stimulate a positive response in Achilles tendon thickness. [ABSTRACT FROM AUTHOR]

Aims: Traditional criteria for heart transplantation by cardiopulmonary exercise testing (CPX) include peak oxygen uptake (VO2) < 14 mL/kg/min. Reaching a sufficient exercise load is challenging for patients with refractory heart failure (HF) because of their exercise intolerance. Recently, a substantial impact of right ventricular (RV) dysfunction was highlighted on urgent heart transplantation and mortality. This study aims to investigate the impact of RV contractile reserve, assessed by low‐load exercise stress echocardiography (ESE), on exercise intolerance defined as peak VO2 < 14 mL/kg/min, in patients with HF. Methods and results: We prospectively examined 67 consecutive patients hospitalized for HF who underwent ESE and CPX under a stabilized HF condition. Although low‐load ESE was defined as 25 W load exercise, an increment in RV systolic (s′) velocity was regarded as the preservation of RV contractile reserve. All patients completed low‐load ESE. During low‐load ESE, the variation in RV s′ velocity significantly correlated with peak VO2 (r = 0.787, P < 0.001). The change in RV s′ velocity during low‐load ESE accurately identified patients with peak VO2 < 14 mL/kg/min (area under the curve, 0.95; sensitivity, 92%; specificity, 85%). The intraclass correlation coefficient for intra‐observer and inter‐observer agreement for the change in RV s′ velocity was 0.96 (95% confidence interval, 0.88–0.99, P < 0.001) and 0.86 (95% confidence interval, 0.64–0.95, P < 0.001), respectively. The RV‐to‐pulmonary circulation (PC) coupling, which was assessed by the slope of the relationship between RV s′ velocity and pulmonary artery systolic pressure at rest and low‐load exercise, was worse in the low‐peak VO2 group (<14 mL/kg/min) than the preserved‐peak VO2 group (≥14 mL/kg/min). Conclusions: The change in RV s′ velocity during low‐load ESE could estimate the exercise capacity in HF patients. The assessments of RV contractile reserve and RV‐to‐PC coupling could be clinically beneficial to distinguish high‐risk HF patients. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to perform a meta-analysis to compare the efficacy of heavy (∼80% of one repetition maximum, 1 RM) vs light-moderate load (∼45% 1 RM) resistance training ( RT) programs in inducing strength gains and skeletal muscle hypertrophy in elderly people. To assess the role of training volumes, studies in which training protocols were matched for mechanical work were independently analyzed. In all 15 studies included (448 subjects, age 67.8 years), when comparing heavy with light-moderate loads, strength gains tended to be larger following RT with higher intensities of load, with the resulting total population effect being μ = 0.430 ( P = 0.060). Effect sizes were substantially smaller in 'work-matched' studies (μ = 0.297, P = 0.003). Training with higher loads also provoked marginally larger gains in muscle size, although the degree of training-induced muscle hypertrophy was generally small (0.056 < μ < 0.136). To conclude, provided a sufficient number of repetitions is performed, RT at lower than traditionally recommended intensities of load may suffice to induce substantial gains in muscle strength in elderly cohorts. [ABSTRACT FROM AUTHOR]

There has been much debate as to optimal loading strategies for maximising the adaptive response to resistance exercise. The purpose of this paper therefore was to conduct a meta-analysis of randomised controlled trials to compare the effects of low-load (≤60% 1 repetition maximum [RM]) versus high-load (≥65% 1 RM) training in enhancing post-exercise muscular adaptations. The strength analysis comprised 251 subjects and 32 effect sizes (ESs), nested within 20 treatment groups and 9 studies. The hypertrophy analysis comprised 191 subjects and 34 ESs, nested with 17 treatment groups and 8 studies. There was a trend for strength outcomes to be greater with high loads compared to low loads (difference = 1.07 ± 0.60; CI: −0.18, 2.32;p= 0.09). The mean ES for low loads was 1.23 ± 0.43 (CI: 0.32, 2.13). The mean ES for high loads was 2.30 ± 0.43 (CI: 1.41, 3.19). There was a trend for hypertrophy outcomes to be greater with high loads compared to low loads (difference = 0.43 ± 0.24; CI: −0.05, 0.92;p= 0.076). The mean ES for low loads was 0.39 ± 0.17 (CI: 0.05, 0.73). The mean ES for high loads was 0.82 ± 0.17 (CI: 0.49, 1.16). In conclusion, training with loads ≤50% 1 RM was found to promote substantial increases in muscle strength and hypertrophy in untrained individuals, but a trend was noted for superiority of heavy loading with respect to these outcome measures with null findings likely attributed to a relatively small number of studies on the topic. [ABSTRACT FROM PUBLISHER]

Purpose: We investigated the effect of online home exercise training using a video communication tool on fitness parameters compared to the same exercises supervised directly. Methods: In the present study, 34 subjects (age: 42.9±14.4 years) were included. Twenty-three subjects performed 8 weeks of body weight-based exercise training online using Zoom, and 11 subjects performed the same exercise supervised directly as the control group. The subjects performed low-load resistance exercise twice a week for 8 weeks for a total of 16 sessions. The sessions included 9 exercises: leg raises, squats, rear raises, shoulder presses, rowing, dips, lunges, Romanian dead lifts, and push-ups. The chair-stand, push-up, and sit-and-reach tests were performed by all subjects. Results: The training program effectively increased the chair-stand and sit-and-reach test results, but the online group gained substantially less body mass than the control group. The online and control groups gained similar amounts of body mass on the push-up test. Conclusion: Our results show that there is a similar training response to body mass-based training in both groups, even with virtual experiences using Zoom. [ABSTRACT FROM AUTHOR]

An abstract of the article "Effectiveness of low-load exercise program on bone health, physical fitness and an artery function in middle-aged and older men and women," by Yasuo Kimura, Mamoru Hisatomi and Masanori Nakayama is presented.