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Nutrition & Metabolism Jul 2024Maintaining skeletal muscle mass is important for improving muscle strength and function. Hence, maximizing lean body mass (LBM) is the primary goal for both elite... (Review)
Review
Maintaining skeletal muscle mass is important for improving muscle strength and function. Hence, maximizing lean body mass (LBM) is the primary goal for both elite athletes and fitness enthusiasts. The use of amino acids as dietary supplements is widespread among athletes and physically active individuals. Extensive literature analysis reveals that branched-chain amino acids (BCAA), creatine, glutamine and β-alanine may be beneficial in regulating skeletal muscle metabolism, enhancing LBM and mitigating exercise-induced muscle damage. This review details the mechanisms of these amino acids, offering insights into their efficacy as supplements. Recommended dosage and potential side effects are then outlined to aid athletes in making informed choices and safeguard their health. Lastly, limitations within the current literature are addressed, highlighting opportunities for future research.
PubMed: 38956658
DOI: 10.1186/s12986-024-00820-0 -
BMC Sports Science, Medicine &... Jul 2024Applying whole-body electromyostimulation (wbEMS) to voluntary activation of the muscle is known to impact motor unit recruitment. Thus, wbEMS as an additional training...
BACKGROUND
Applying whole-body electromyostimulation (wbEMS) to voluntary activation of the muscle is known to impact motor unit recruitment. Thus, wbEMS as an additional training stimulus enhances force-related capacities. This study aimed to evaluate the mono- and multiarticular strength adaptations to a running intervention with wbEMS compared to running without wbEMS.
METHODS
In a randomized controlled trial (RCT), 59 healthy participants (32 female/ 27 male, 41 ± 7 years) with minor running experience conducted an eight-week running intervention (2x/ week à 20 min) with a wbEMS suit (EG) or without wbEMS (control group, CG). Maximal isokinetic knee extensor and flexor strength and jump height during countermovement jumps were recorded prior and after the intervention to assess maximal strength and power.
RESULTS
Following eight weeks of running, maximal isokinetic knee extension torque decreased significantly over time for both interventions (EG -4%, CG -4%; F(1, 44.14) = 5.96, p = 0.02, = 0.12). No changes were observed for flexion torque (F(1, 43.20) = 3.93, p = 0.05, = 0.08) or jump height (F(1, 43.04) = 0.32, p = 0.57, = 0.01).
CONCLUSIONS
The outcomes indicate that there is no additional effect over neuromuscular function adaptations with the inclusion of wbEMS during running training. Knee extensor strength is even slightly reduced which supports the principle of training specificity in regards to strength adaptation. We conclude that strength improvements cannot be achieved by running with wbEMS.
TRIAL REGISTRATION
German Clinical Trials Register, ID DRKS00026827, date 10/26/21.
PubMed: 38956590
DOI: 10.1186/s13102-024-00931-4 -
Scientific Reports Jul 2024Plyometric training is characterized by high-intensity exercise which is performed in short term efforts divided into sets. The purpose of the present study was twofold:... (Randomized Controlled Trial)
Randomized Controlled Trial
Plyometric training is characterized by high-intensity exercise which is performed in short term efforts divided into sets. The purpose of the present study was twofold: first, to investigate the effects of three distinct plyometric exercise protocols, each with varying work-to-rest ratios, on muscle fatigue and recovery using an incline-plane training machine; and second, to assess the relationship between changes in lower limb muscle strength and power and the biochemical response to the three exercise variants employed. Forty-five adult males were randomly divided into 3 groups (n = 15) performing an exercise of 60 rebounds on an incline-plane training machine. The G0 group performed continuous exercise, while the G45 and G90 groups completed 4 sets of 15 repetitions, each set lasting 45 s with 45 s rest in G45 (work-to-rest ratio of 1:1) and 90 s rest in G90 (1:2 ratio). Changes in muscle torques of knee extensors and flexors, as well as blood lactate (LA) and ammonia levels, were assessed before and every 5 min for 30 min after completing the workout. The results showed significantly higher (p < 0.001) average power across all jumps generated during intermittent compared to continuous exercise. The greatest decrease in knee extensor strength immediately post-exercise was recorded in group G0 and the least in G90. The post-exercise time course of LA changes followed a similar pattern in all groups, while the longer the interval between sets, the faster LA returned to baseline. Intermittent exercise had a more favourable effect on muscle energy metabolism and recovery than continuous exercise, and the work-to-rest ratio of 1:2 in plyometric exercises was sufficient rest time to allow the continuation of exercise in subsequent sets at similar intensity.
Topics: Humans; Male; Rest; Muscle Fatigue; Adult; Muscle Strength; Plyometric Exercise; Young Adult; Muscle, Skeletal; Lactic Acid; Ammonia; Exercise
PubMed: 38956280
DOI: 10.1038/s41598-024-66146-2 -
Physiological Reports Jul 2024
PubMed: 38955801
DOI: 10.14814/phy2.16135 -
Zhonghua Er Ke Za Zhi = Chinese Journal... Jul 2024To summarize the clinical manifestations, diagnosis, treatment and prognosis of acute flaccid myelitis (AFM) in children. Clinical characteristics of 4 AFM cases from...
To summarize the clinical manifestations, diagnosis, treatment and prognosis of acute flaccid myelitis (AFM) in children. Clinical characteristics of 4 AFM cases from Department of Neurology, Children's Hospital Affiliated to Capital Institute of Pediatrics, from September 2018 to November 2022, were analyzed retrospectively. The age of 4 children with AFM was 7 years, 4 years and 3 months, 7 years and 1 month, 6 years and 5 months, respectively. There were 2 boys and 2 girls. Prodromal infection status showed 3 children of respiratory tract infection and 1 child of digestive tract infection. The main manifestation was asymmetrical limb weakness after infection, and the affected limb range was from monoplegia to quadriplegia. Cranial nerve injury was involved in 1 child, no encephalopathy. Magnetic resonance imaging in the spinal cord of all 4 children showed long T1 and T2 signals, mainly involving gray matter. Cerebrospinal fluid cell-protein separation was observed in 2 children. Pathogen detected in 1 child pharyngeal swab was enterovirus D68. Antibody IgM to adenovirus was positive in the blood of 1 child. Antibody IgG against Echo and Coxsackie B virus were positive in the blood of another child. After glucocorticoid, human immunoglobulin or simple symptomatic treatment and at the same time under later rehabilitation training, muscle strength recovered to different degrees, but there were disabilities left in 3 children. AFM should be considered in children with acute and asymmetrical flaccid paralysis accompanied by abnormal magnetic resonance imaging signal in the central region of spinal cord, especially post-infection. The effective treatment is limited and the prognosis is poor.
Topics: Humans; Myelitis; Male; Female; Child; Child, Preschool; Retrospective Studies; Magnetic Resonance Imaging; Central Nervous System Viral Diseases; Neuromuscular Diseases; Enterovirus D, Human; Prognosis; Spinal Cord; Enterovirus Infections; Quadriplegia; Respiratory Tract Infections
PubMed: 38955687
DOI: 10.3760/cma.j.cn112140-20240320-00191 -
Saudi Medical Journal Jul 2024To assess the prevalence of anabolic steroid use and the level of knowledge on anabolic steroids among the male athletes in Al Madina Al Munawara, Saudi Arabia.
OBJECTIVES
To assess the prevalence of anabolic steroid use and the level of knowledge on anabolic steroids among the male athletes in Al Madina Al Munawara, Saudi Arabia.
METHODS
A cross-sectional study was conducted on male athletes randomly selected from the private athletic centers in Al Madina Al Munawara over 5 months. Data were collected from all participants using a self-administered anonymous questionnaire with 33 questions. The questionnaire covered the socio-demographic characteristics of the participants, and their knowledge, attitudes, and use of anabolic steroids.
RESULTS
Of the 150 male athletes surveyed, 121 completed the questionnaire (response rate: 80.6%). Over half were aged between 18 and 23 years (56.2%) and were single (79.3%). Thirty-two percent reported using anabolic steroids, mainly to increase muscle mass, following coaches' advice (46.1%). Key sources included the internet (30.7%), coaches (30%), and friends (27.9%), and non-healthcare professionals. The top motivations were price, coach's/physician's advice, and availability. The perceived benefits included increased muscle mass, strength, and endurance, while the perceived adverse effects included kidney/liver damage and sexual problems.
CONCLUSION
One-third of the male athletes surveyed used anabolic steroids, influenced by accessibility and social contact, rather than healthcare guidance. This highlights the need for greater awareness of the long-term health risks, ideally through education provided by sports medicine specialists.
Topics: Humans; Male; Saudi Arabia; Athletes; Young Adult; Cross-Sectional Studies; Anabolic Agents; Adolescent; Adult; Health Knowledge, Attitudes, Practice; Prevalence; Surveys and Questionnaires; Doping in Sports; Anabolic Androgenic Steroids
PubMed: 38955450
DOI: 10.15537/smj.2024.45.7.20240244 -
Archives of Gerontology and Geriatrics Jun 2024Sarcopenic obesity is a combination of sarcopenia and obesity, which is associated with the onset of disability. Fat to muscle ratio (FMR) is a screening measure that...
PURPOSE
Sarcopenic obesity is a combination of sarcopenia and obesity, which is associated with the onset of disability. Fat to muscle ratio (FMR) is a screening measure that assesses the ratio of muscle mass to fat mass. However, the relationship between the FMR and disability has not been investigated.
METHODS
This study included 11,427 community-dwelling older adults aged ≥65 years enrolled in NCGG-SGS (National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes), a national cohort study in Japan. FMR was measured by the bioelectrical impedance analysis and calculated by dividing fat mass by muscle mass. Cox proportional hazard regression analysis adjusted for covariates was used to investigate the association between FMR and the risk of developing new care needs at 5 years. FMR was divided by about quintile, with quintile 5 as the high.
RESULTS
The high FMR group had the highest incidence of disability at 20.8 % for women and 20.1 % for men. In women, the association between FMR and disability was significantly different for the FMR (hazard risk [HR]: 1.43, 95 % confidence interval [CI]: 1.16-1.75). There was no association between FMR and disability in men (HR: 0.98, 95 %CI: 0.76-1.25). Lagged analyses accounting for reverse causality did not change the relationship.
CONCLUSIONS
FMR is associated with increased risk of disability in women community-dwelling older adults but not among men. Because the rate of decreased muscle strength is faster in men than in women, early decreased muscle strength may affect men's risk of disability more than muscle mass or fat mass.
PubMed: 38954986
DOI: 10.1016/j.archger.2024.105524 -
Gait & Posture Jun 2024Individuals with myelomeningocele (MMC) present with neurological and orthopaedic deficiencies, requiring orthoses during walking. Orthoses for counteracting...
BACKGROUND
Individuals with myelomeningocele (MMC) present with neurological and orthopaedic deficiencies, requiring orthoses during walking. Orthoses for counteracting dorsiflexion may restrict activities such as rising from a chair.
RESEARCH QUESTION
How are sit-to-stand (STS) movements performed with ankle joint-restricted ankle-foot orthoses (AFO) and knee-ankle-foot orthoses with a free-articulated knee joint (KAFO-F)?
METHODS
Twenty-eight adults with MMC, mean age 25.5 years (standard deviation: 3.5 years), were divided into an AnkleFree group (no orthosis or a foot orthosis) and an AnkleRestrict group (AFOs or KAFO-Fs). Study participants performed the five times STS test (5STS) while their movements were simultaneously captured with a three-dimensional motion system. Centre of mass (CoM) trajectories and joint kinematics were analysed using statistical parametric mapping.
RESULTS
The AnkleRestrict group performed the STS slower than the AnkleFree group, median 8.8 s (min, max: 6.9, 14.61 s) vs 15.0 s (min, max: 7.5, 32.2 s) (p = 0.002), displayed reduced ankle dorsiflexion (mean difference: 6°, p = 0.044) (74-81 % of the STS cycle), reduced knee extension (mean difference: 14°, p = 0.002) (17-41 % of the STS cycle), larger anterior pelvic tilt angle (average difference: 11°, p = 0.024) (12-24 % of the STS cycle), and larger trunk flexion angle (on average 4°, p = 0.029) (6-15 % of the STS cycle).
SIGNIFICANCE
The differences between the AnkleFree and AnkleRestrict groups in performing the STS seem consistent with the participants functional ambulation: community ambulation in the AnkleFree group, and household and nonfunctional ambulation with less hip muscle strength in the majority of the AnkleRestrict group. No differences in the 5STS CoM trajectories or the kinematics were found with respect to the AFO and KAFO-Fs groups. Because orthoses are constructed to enable walking, the environment needs to be adjusted for activities in daily living such as the STS movement.
PubMed: 38954928
DOI: 10.1016/j.gaitpost.2024.06.025 -
American Journal of Physical Medicine &... Jul 2024This study aimed to assess the effects of aquatic therapy in individuals with hemiplegia compared to those of a conventional land-based exercise program.
OBJECTIVE
This study aimed to assess the effects of aquatic therapy in individuals with hemiplegia compared to those of a conventional land-based exercise program.
DESIGN
This was a blinded, randomized controlled study of chronic stroke patients with hemiplegia. The participants were randomized in to aquatic therapy (experimental) or conventional therapy (control) groups. The aquatic therapy group conducted the exercise program in a swimming pool, and the conventional therapy group performed to an exercise on the land environment three times per week for six weeks. Both interventions focused on posture, balance, and weight-bearing exercises. Outcomes included the Berg Balance Scale, Brunnstrom scale, Motricity Index, muscle strength tests, Modified Ashworth Scale, Postural Assessment Scale for Stroke, Trunk Control Test and Functional Independence Measure. Also, postural sway was evaluated by using the variables of center of pressure displacements in the mediolateral and anteroposterior directions.
RESULTS
The findings of the present study show that the experimental group (26 patients) exhibited significant improvements in spasticity compared to the control group (25 patients) (p = 0.01). The conventional therapy group also achieved significant improvements (p < 0.05) in anteroposterior deviation, mediolateral velocity, and total velocity of center of pressure in a sitting position with eyes closed.
CONCLUSION
Land-based exercises were more beneficial in the spasticity of chronic stroke patients.
PubMed: 38954645
DOI: 10.1097/PHM.0000000000002589 -
International Journal of Clinical... Jul 2024Pancreatic cancer is still a difficult disease to treat, despite recent advances in surgical techniques and chemotherapeutic drugs. Its incidence continues to rise, as... (Review)
Review
Pancreatic cancer is still a difficult disease to treat, despite recent advances in surgical techniques and chemotherapeutic drugs. Its incidence continues to rise, as does the number of older patients. Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass and strength. Sarcopenia is present in approximately 40% in patients with pancreatic cancer. Sarcopenia is primarily diagnosed through imaging, and progress is being made in the development of automated methods and artificial intelligence, as well as biomarker research. Sarcopenia has been linked to a poor prognosis in pancreatic cancer patients. However, some studies suggest that sarcopenia is not always associated with a poor prognosis, depending on the resectability of pancreatic cancer and the nature of treatment, such as surgery or chemotherapy. Recent meta-analyses have found that sarcopenia is not linked to postoperative complications. It is still debated whether there is a link between sarcopenia and drug toxicity during chemotherapy. The relationship between sarcopenia and immunity has been investigated, but the mechanism is still unknown.
PubMed: 38954075
DOI: 10.1007/s10147-024-02576-2