133 research outputs found
Malproduction of endogenous hydrogen gas in COVID-19
The molecular footprints of COVID-19 occur everywhere, even reaching the family of biologically active gases and gasotransmitters. Besides nitric oxide and hydrogen sulfide, COVID-19 might also alter the homeostasis of dihydrogen (H2), another gaseous bioactive molecule produced endogenously by the human gut bacteria. Many studies have shown various alterations of the gut microbiota in patients with coronavirus disease 2019, including the lower abundance of hydrogen-producing bacteria that could instigate the shortage of hydrogen output. Since dihydrogen has many important bioactivities, including cytoprotective, antioxidant, anti-inflammatory, and antiapoptotic, its malproduction in COVID-19 might contribute to the disease progression and severity. On the other hand, replenishing dihydrogen by exogenous administration could be beneficial in COVID-19 for both patient- and clinical-reported outcomes. Assessing low dihydrogen along with H2 supplementation to restore normal levels could be thus combined via theranostic approaches to aid COVID-19 diagnosis and treatment
Correlation between Fitness and Fatness in 6-14-year Old Serbian School Children
Lack of physical activity and/or physical fitness are some reasons epidemiologists suggest for increase in childhood obesity in the last 20 years, with clear correlation between body composition and physical activity and/or physical fitness yet to be determined. The objectives of the study were to (a) investigate the prevalence of overweight and obesity among Serbian school children and (b) determine the relationship between indicators of physical activity and body fatness in Serbian school children aged 6-14 years. The study subjects included a representative sample of Serbian elementary school children (n=1, 121—754 boys and 367 girls—aged 6.2-14.1 years), all of whom were recruited in the OLIMP (Obesity and Physical Activity among Serbian School Children) study. Anthropometric and physical fitness values, including body mass index (BMI), waist-circumference, body-fat, and aerobic capacity, were measured in all the children. Significant differences were found between male and female children regarding the prevalence of obesity (6.8% vs 8.2%, p<0.05, boys and girls respectively). Boys had significantly lower body mass, BMI, waist-circumference, sum of six skinfolds, and body-fat compared to their female counterparts (p<0.05). The highest level of weight, BMI, body-fat, and waist-circumference observed in a 14-year old girl (96.3 kg, 40.5 kg/m2, 54.5%, 91.4 cm respectively) implies the existence of extreme obesity in Serbian school children. The negative relationship between body-fat and maximal oxygen (VO2max) uptake was moderately high (r=-0.76; p<0.05). The study has shown a high prevalence of adiposity among Serbian school children, with a strong negative relationship between aerobic fitness and body fatness. Data of the study emphasize the necessity to identify children with weight problems and to develop early interventions to improve physical activity in children and prevent the increase of childhood obesity
Effects of acute b-alanine supplemetation 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 4x400 m running fatigue protocol was carried out to produce fatigue. After the fatigue protocol, the same jumping tests were repeated, CMJ and CMJ-4, to evaluate the loss in jump height. The Mann-Whitney U test was used to analyze differences between the groups, whereas Wilcoxon signed-rank test was conducted to analyze differences within the groups with statistical significance set at p<.05. After β-alanine supplementation, no significant decrease in jump height was found in the experimental group in none of the tests after the fatigue protocol. Conversely, a significant decrease was noticed in the placebo group in CMJ but not in the CMJ-4 test. In conclusion, an acute β-alanine supplementation could attenuate jump height loss after the fatigue protocol. Therefore, athletes and coaches should consider acute β-alanine supplementation to attenuate sports performance decrease after high-intensity exercises in which muscle acidosis is highly increased
Correlation between Fitness and Fatness in 6-14-year Old Serbian School Children
Lack of physical activity and/or physical fitness are some reasons
epidemiologists suggest for increase in childhood obesity in the last
20 years, with clear correlation between body composition and physical
activity and/or physical fitness yet to be determined. The objectives
of the study were to (a) investigate the prevalence of overweight and
obesity among Serbian school children and (b) determine the
relationship between indicators of physical activity and body fatness
in Serbian school children aged 6-14 years. The study subjects included
a representative sample of Serbian elementary school children
(n=1,121\u2014754 boys and 367 girls\u2014aged 6.2-14.1 years), all
of whom were recruited in the OLIMP (Obesity and Physical Activity
among Serbian School Children) study. Anthropometric and physical
fitness values, including body mass index (BMI), waist-circumference,
body-fat, and aerobic capacity, were measured in all the children.
Significant differences were found between male and female children
regarding the prevalence of obesity (6.8% vs 8.2%, p<0.05, boys and
girls respectively). Boys had significantly lower body mass, BMI,
waist-circumference, sum of six skinfolds, and body-fat compared to
their female counterparts (p<0.05). The highest level of weight,
BMI, body-fat, and waist-circumference observed in a 14-year old girl
(96.3 kg, 40.5 kg/m2, 54.5%, 91.4 cm respectively) implies the
existence of extreme obesity in Serbian school children. The negative
relationship between body-fat and maximal oxygen (VO2max) uptake was
moderately high (r=-0.76; p<0.05). The study has shown a high
prevalence of adiposity among Serbian school children, with a strong
negative relationship between aerobic fitness and body fatness. Data of
the study emphasize the necessity to identify children with weight
problems and to develop early interventions to improve physical
activity in children and prevent the increase of childhood obesity
Komparativna studija izmjerenog i procijenjenog vo2max u višestupanjskom funkcionalnom testu pripremljenosti nogometaša juniora
The multi-stage 20-m shuttle run test (MSRT) is one of the most popular field tests using equations based on test results or the final speed for an indirect estimation of maximal oxygen uptake (VO2max). The aim of this study was to compare the real VO2max value to the predicted value of VO2max by MSRT and rate the usefulness of the MSRT as a predictor of VO2max in young football players. Fifteen young football players, nominees for the 2004/2005 national Under-18 team, were included in this study. The subjects were 17.9±.2 years old, had an average height of 178.8±7 cm and an average weight of 71.8±7.5 kg. The players came from different Slovenian junior premier football league clubs and trained on average 4 to 5 times per week. Testing was conducted on all subjects over two days, between 9 a.m. and 2 p.m., on synthetic turf. A mobile device for the measurement of O2 and CO2 in expired air and ventilation during MSRT was used. On the basis of the test result (the number of levels and repetitions between them) VO2max was calculated. The correlation between the measured and predicted VO2max was determined with Pearson’s correlation coefficient. The comparison of both mean values showed that the measured value was significantly higher (p<.05), by as much as 8.5 ml O2 kg-1•min-1, than the MSRT-predicted VO2max. Variables were statistically correlated, but the correlation coefficient amounted to only .58. This study has shown that an indirect evaluation of aerobic
capacity based on the multi-stage 20 m shuttle run test can lead to wrong conclusions in young soccer players. The correlation observed between the measured and predicted VO2max was too weak to predict the aerobic capacity of young football players with certainty.Višestupanjski test povratnog trčanja dionica od 20 metara (MSRT) je jedan od najpopularnijih terenskih testova koji koriste jednadžbe za procjenu maksimalnog primitka kisika (VO2max) na temelju ukupnog rezultata testa ili konačne brzine trčanja na kraju testa. Cilj ovog istraživanja bio je usporediti stvarne vrijednosti VO2max s procijenjenim vrijednostima VO2max dobivenima pomoću MSRT te
ocijeniti korisnost toga terenskog višestupanjskog testa kao prediktora VO2max u mladih nogometaša. U istraživanje je bilo uključeno 15 mladih nogometaša izabranih za slovensku nacionalnu selekciju
U18 u sezoni 2004./2005. Ispitanici su bili u dobi od 17,9±0,2 godina, prosječne visine 178,8±7 cm i prosječne težine 71,8±7,5 kg. Igrači su bili članovi različitih slovenskih prvoligaških juniorskih klubova
i trenirali su u prosjeku 4 do 5 puta tjedno. Testiranje je provedeno na svim ispitanicima tijekom dva dana, u vremenu između 9 i 14 sati na umjetnoj travi. Korišteni su prijenosni uređaji za mjerenje O2 i CO2 u izdahnutomu zraku i ventilacije tijekom provedbe MSRT. Na temelju rezultata testa (razina otkaza i broj ponavljanja unutar razine otkaza)
izračunat je VO2max. Povezanost između izmjerenoga i procijenjenoga VO2max utvrđena je Pearsonovim koeficijentom korelacije. Usporedba prosječnih vrijednosti pokazala je da je izmjerena vrijednost VO2max bila statistički značajno viša (p<0,05) za 8,5 ml O2 kg-1•min-1 od procijenjene vrijednosti VO2max koja je izračunata pomoću MSRT. Korelacija između varijabli bila je statistički značajna, ali je korelacijski
koeficijent bio samo 0,58. Ovo je istraživanje pokazalo da neizravno vrednovanje aerobnoga kapaciteta rezultatima u testu MSRT može dovesti do pogrešnih zaključaka na populaciji mladih nogometaša.
Utvrđena povezanost između izmjerene i procijenjene vrijednosti VO2max bila je preslaba da bi sa sigurnošću mogla poduprijeti procjenu aerobnoga kapaciteta u mladih nogometaša
The effect of rapid weight loss on body composition and circulating markers of creatine metabolism in judokas
We evaluated the effects of a 7-day rapid weight loss (RWL) intervention on body composition and biomarkers of creatine metabolism in eight elite judokas during a pre-competition period. RWL induced a significant drop in weight (81.7±10.7 kg at baseline vs. 76.8 ± 10.3 kg at follow-up; p<.001), fat mass (12.6±5.6 kg vs. 9.2±4.0 kg; p=.003) and fat-free mass (69.1±7.3 kg vs. 67.6±7.7 kg; p=.05), accompanied by an increase in serum creatinine levels at follow-up (104.0±10.5 μmol/L vs. 114.9±10.2 μmol/L; p=.009). An acute restriction of food and fluid intake appears to negatively affect fat-free mass and indices of kidney function in judokas
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