EFFECTS OF OFF-SEASON RESISTANCE TRAINING ON ANAEROBIC POWER AND MUSCLE STRENGTH OF HIGH SCHOOL BASEBALL PLAYERS

Objective: This meta-analysis aimed to evaluate the effectiveness of low-load Resistance Training (RT) with or without Blood Flow Restriction (BFR) compared with conventional RT on muscle strength in open and closed kinetic chains, muscle volume and pain in individuals with orthopaedic impairments. Data sources: Searches were conducted in the PubMed, Web of Science, Scopus and Cochrane databases, including the reference lists of randomised controlled trials (RCT’s) up to January 2021. Review method: An independent reviewer extracted study characteristics, orthopaedic indications, exercise data and outcome measures. The primary outcome was muscle strength of the lower limb. Secondary outcomes were muscle volume and pain. Study quality and reporting was assessed using the TESTEX scale. Results: A total of 10 RCTs with 386 subjects (39.2 ± 17.1 years) were included in the analysis to compare low-load RT with BFR and high or low-load RT without BFR. The meta-analysis showed no significant superior effects of low-load resistance training with BFR regarding leg muscle strength in open and closed kinetic chains, muscle volume or pain compared with high or low-load RT without BFR in subjects with lower limb impairments. Conclusion: Low-load RT with BFR leads to changes in muscle strength, muscle volume and pain in musculoskeletal rehabilitation that are comparable to conventional RT. This appears to be independent of strength testing in open or closed kinetic chains.

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Augmentation Index Is Inversely Associated with Skeletal Muscle Mass, Muscle Strength, and Anaerobic Power in Young Male Adults: A Preliminary Study

Applied Sciences ◽

10.3390/app11073146 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3146

Author(s):

Dongmin Lee ◽

Kyengho Byun ◽

Moon-Hyon Hwang ◽

Sewon Lee

Keyword(s):

Skeletal Muscle ◽

Muscle Strength ◽

Arterial Stiffness ◽

Muscle Mass ◽

Muscular Strength ◽

Skeletal Muscle Mass ◽

Augmentation Index ◽

Anaerobic Power ◽

Negatively Associated ◽

Increased Risk

Arterial stiffness is associated with an increased risk of cardiovascular disease. Previous studies have shown that there is a negative correlation between arterial stiffness and variables such as skeletal muscle mass, muscular strength, and anaerobic power in older individuals. However, little research has been undertaken on relationships in healthy young adults. This study presents a preliminary research that investigates the association between arterial stiffness and muscular factors in healthy male college students. Twenty-three healthy young males (23.9 ± 0.5 years) participated in the study. The participants visited the laboratory, and variables including body composition, blood pressure, arterial stiffness, blood parameters, grip strength, and anaerobic power were measured. Measurements of augmentation index (AIx) and brachial-ankle pulse wave velocity (baPWV) were performed to determine arterial stiffness. There were significant positive correlations among skeletal muscle mass, muscle strength, and anaerobic power in healthy young adult males. AIx was negatively associated with a skeletal muscle mass (r = −0.785, p < 0.01), muscular strength (r = −0.500, p < 0.05), and anaerobic power (r = −0.469, p < 0.05), respectively. Likewise, AIx@75 corrected with a heart rate of 75 was negatively associated with skeletal muscle mass (r = −0.738, p < 0.01), muscular strength (r = −0.461, p < 0.05), and anaerobic power (r = −0.420, p < 0.05) respectively. However, the baPWV showed no correlation with all muscular factors. Our findings suggest that maintaining high levels of skeletal muscle mass, muscular strength, and anaerobic power from relatively young age may lower AIx.

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Posterior-Chain Resistance Training Compared to General Exercise and Walking Programmes for the Treatment of Chronic Low Back Pain in the General Population: A Systematic Review and Meta-Analysis

Sports Medicine - Open ◽

10.1186/s40798-021-00306-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Nicholas Tataryn ◽

Vini Simas ◽

Tailah Catterall ◽

James Furness ◽

Justin W. L. Keogh

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Resistance Training ◽

Muscle Strength ◽

Adverse Events ◽

Muscular Strength ◽

Meta Analysis ◽

Low Back ◽

Pain Level ◽

General Exercise

Abstract Background While chronic exercise training has been demonstrated to be an effective non-pharmacological treatment for chronic low back pain (CLBP), there has been a relative lack of evidence or clinical guidelines for whether a posterior chain resistance training programme provides any benefits over general exercise (GE). Objectives To determine if chronic posterior chain resistance training (PCRT), defined as exercise programmes of ≥6 weeks duration focused on the thoracic, lumbar and hip extensor musculature, is more effective than GE in improving pain, level of disability, muscular strength and the number of adverse events in recreationally active and sedentary individuals with CLBP. Methods Four electronic databases were systematically searched from 25 September 2019 until 30 August 2020. Using the Joanna Briggs Institute (JBI) Critical Appraisal Tools checklist for randomized controlled trials (RCTs), articles were critically appraised and compared against the inclusion/exclusion criteria. Standardized mean difference (SMD), risk difference (RD) and confidence interval (CI) were calculated using Review Manager 5.3. Results Eight articles were included, with a total of 408 participants (203 PCRT, 205 GE). Both PCRT and GE were effective in improving a number of CLBP-related outcomes, but these effects were often significantly greater in PCRT than GE, especially with greater training durations (i.e. 12–16 weeks compared to 6–8 weeks). Specifically, when compared to GE, PCRT demonstrated a greater reduction in pain (SMD = − 0.61 (95% CI − 1.21 to 0.00), p = 0.05; I2 = 74%) and level of disability (SMD = − 0.53 (95% CI − 0.97 to − 0.09), p = 0.02; I2 = 52%), as well as a greater increase in muscle strength (SMD = 0.67 (95% CI 0.21 to 1.13), p = 0.004; I2 = 0%). No differences in the number of adverse events were reported between PCRT and GE (RD = − 0.02 (95% CI − 0.10 to 0.05), p = 0.57; I2 = 72%). Conclusion Results of the meta-analysis indicated that 12–16 weeks of PCRT had a statistically significantly greater effect than GE on pain, level of disability and muscular strength, with no significant difference in the number of adverse events for recreationally active and sedentary patients with CLBP. Clinicians should strongly consider utilizing PCRT interventions for 12–16 weeks with patients with CLBP to maximize their improvements in pain, disability and muscle strength. Future research should focus on comparing the efficacy and adverse events associated with specific PCRT exercise training and movement patterns (i.e. deadlift, hip lift) in treating this population. Trial registration PROSPERO CRD42020155700.

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