0000000000318996
AUTHOR
Valdemar Stajer
Effects of acute b-alanine supplementation on countermovement jump performance after a 4x400 m fatigue protocol: A randomized, double-blind, placebo-controlled trial
This study aimed to examine the effect of acute beta-alanine (β-alanine) supplementation on jump performance after a strenuous fatigue protocol. Twelve healthy young men (age 21.4±0.5 years, body height 180.2±5.8 cm, body mass 76.6±9.2 kg) volunteered to participate in this randomized, double-blind, placebo-controlled trial. The experimental group ingested 3.2 g of β-alanine (separated into two 1.6 g dosages) mixed with 23 g of glucose, whereas the placebo group ingested two dosages containing 23 g of glucose. Following the supplementation intake, participants completed a jump protocol involving countermovement jump (CMJ) and four consecutive countermovement jumps (CMJ-4). Subsequently, a 4…
Rapid Weight Loss Habits before a Competition in Sambo Athletes
Background: Like other combat sports, sambo has competition rules that divide athletes into categories based on gender, age and weight. Athletes in combat sports often resort to rapid weight loss (RWL) methods to be more competitive in lower weight categories and gain an advantage against lighter, smaller and weaker competitors. The aim of this study was to examine the methodology implemented by two different sambo age categories, junior and senior athletes, in order to attain RWL. Methods: The sample consisted of 103 male sambo elite athletes (seniors/juniors: age 28.5 ± 4.3/18.9 ± 0.8
Guanidinoacetate-creatine in secondary progressive multiple sclerosis: a case report.
Acute secondary progressive multiple sclerosis (SPMS) is characterized by escalating neurological disability, with limited disease-modifying therapeutic options. A 48-year-old woman with acute SPMS being treated with interferon beta-1a and oral corticosteroids presented as a clinical outpatient with no disease-modifying effects after treatment. A decision was made to treat her with a combination of guanidinoacetate and creatine for 21 days. She had made clinical progress at follow-up, with the intensity of fatigue dropping from severe to mild. Magnetic resonance spectroscopy revealed increased brain choline, creatine, N-acetylaspartate, and glutathione. Patients with SPMS may benefit from …
Prevalence of rapid weight loss in Olympic style wrestlers
Background: The methodology applied for rapid weight loss (RWL) among elite wrestlers is quite unexplored. Therefore, the aim of this study was to analyze the prevalence of sources of influence and methods used for RWL and to determine the differences between wrestling styles. Methods: A total of 229 wrestlers who competed at the World Championship held in Belgrade, Serbia, participated in this research. All respondents completed a questionnaire designed to evaluate RWL patterns in combat athletes. Participants were classified according to wrestling style: Greco-Roman, freestyle, and women wrestling. Results: Sixty-nine percent of wrestlers had previously lost weight to compete. Most respon…
The effects of rapid weight loss on skeletal muscle in judo athletes
Abstract Objective To observe the effect of rapid weight loss (RWL) methods over 3 days on muscle damage in judokas. Methods Eighteen judokas participated in this crossover study, meaning that judo athletes were subjected to exercise-only phase (4 days) and RWL phase (3 days). Subjects were tested for myoglobin, creatine kinase, aldolase, hemoglobin, and hematocrit values on seven consecutive days. These biomarkers served as indicators of acute muscle damage. Results During the exercise-only phase, no significant changes were observed. Myoglobin (Mb) (p < 0.001), creatine kinase (CK) (p < 0.001) and aldolase (ALD) (p < 0.001) significantly increased only during the RWL phase, as we…
Cardiac response to Nage no Kata in judo
The first world judo Kata competition was held in October 2007 in Tokyo, Japan. The Nage no Kata was developed in 1884 and 1885 at the Kodokan. by Jigoro Kano, the founder of judo, who developed Kata to demonstrate the principles of judo and to provide a type of training which emphasized performing techniques under controlled setting. According to Kano, to fully develop judo skills, it is essential to involve both Randori and Kata techniques [1]. Most highgrade Japanese judo teachers emphasize the importance of Kata performance for judokas’ development, in particular Nage no Kata [2]. Results of the study conducted by Canestri et al. [3] suggested that session-RPE and HR monitoring is a sim…
Guanidinoacetic Acid Consumption via Regular Diet in Adults
Cardiorespiratory fitness in volleyball athletes following a covid-19 infection: A cross-sectional study
Athletes’ lifestyles have been dramatically affected by the coronavirus disease 2019 (COVID-19) pandemic. Since COVID-19 primarily affects the respiratory system and to a lesser degree the cardiovascular system, the goal of this study was to examine the effects of COVID-19-caused detraining on cardiorespiratory fitness (CRF) of recently recovered volleyball athletes. Sixteen experienced volleyball athletes (age 24 ± 4.5 years) who were recently diagnosed and recovered from a COVID-19 infection volunteered to participate in this study and were tested for CRF and spirometry. Given that participants had only mild symptoms of infection, the primary focus of this study was on the effects of detr…
Creatine consumption and liver disease manifestations in individuals aged 12 years and over
Despite the overwhelming safety evidence concerning creatine intake in various settings, there is still incomplete information whether dietary creatine affects liver health at the population level. The main aim of this cross-sectional population-based study was to evaluate the association between creatine intake through regular diet and liver disease manifestations, including liver fibrosis and hepatic steatosis, among individuals aged 12 years and over, using open-source data from the 2017–2018 U.S. National Health and Nutrition Examination Survey (NHANES). A total of 9254 male and female participants of all ages were included in the 2017–2018 NHANES round. We extracted data from the total…
Patterns of rapid weight loss in elite sambo athletes
Abstract Background Rapid weight loss (RWL) is commonly practiced in combat sports. Both magnitude and methods used to induce RWL are largely similar among combat sports, but currently, there is no data on RWL methodology used by sambo athletes. Therefore, the aim of this study was to determine RWL procedures sambo athletes apply to lose weight rapidly. Methods The sample consisted of 199 participants, of which 132 males and 67 females who participated in the World Sambo Championship 2020 held in Novi Sad, Serbia. Each participant received RWL questionnaire that was available in multiple languages, and every participant was instructed how to fill it out. Results Almost 87% of sambo particip…
sj-pdf-1-imr-10.1177_03000605211073305 - Supplemental material for Guanidinoacetate���creatine in secondary progressive multiple sclerosis: a case report
Supplemental material, sj-pdf-1-imr-10.1177_03000605211073305 for Guanidinoacetate���creatine in secondary progressive multiple sclerosis: a case report by Sergej M. Ostojic, Jelena Ostojic, Dragana Zanini, Tatjana Jezdimirovic and Valdemar Stajer in Journal of International Medical Research
Additional file 1 of The effects of rapid weight loss on skeletal muscle in judo athletes
Additional file 1. Changes in body weight and biomarkers.