جستجوی مقالات مرتبط با کلیدواژه « caffeine » در نشریات گروه « تربیت بدنی »

The aim of this study was to investigate the combined effect of beta-alanine and caffeine on karate specific performance; fatigue and blood lactate of teenage male karatekas.

40 karate teenagers with an average age of 15.26±2.05 years; Height: 175.43±5.77 cm and weight, 69.91±4.10 kg to participate in the study by the available method selected and in 4 groups of 10 subject, control (placebo), beta-alanine, caffeine and The combination of BA and CA were randomly replaced.Caffeine was consumed at a dose of 500 mg/kg body weight once and beta-alanine at a dose of 200 mg/kg body weight for 5 days in two doses. Karate specific performance was measured by using KST (Karate Specific test), anaerobic capacity was measured by RAST test. Also, the blood lactate level of the subjects was measured before taking the supplement and before and after the KST test. Data were analyzed using SPSS version 22 statistical software and analysis of two-way analysis of variance.

Data analysis showed that the karate specific performance variable had a significant improvement in all three supplement groups compared to the control group (p≤0.05). Fatigue index in the caffeine and combined groups and lactate changes were significantly reduced only in the combined group (p≤0.05).

Based on the results of this research, the combined use of beta-alanine and caffeine supplements significantly improved performance and significantly reduced fatigue and blood lactate. Therefore, it is recommended to use a combination of them in the nutritional strategies of karatekas.

     Considering use of caffeinea supplement by athletes and harmful effects of long-term caffeine consumption on male fertility, the aim of this study was determine effect of moderate aerobic exercise combined with Sertoli cell medium conditioning on testicular damage caused by caffeine consumption in adult male rats.For this purpose,30male Wistar rats weighing250±20grams, age9-10weeks, were celected in5 groups(healthy control,affected by caffeine,caffeine-exercise,caffeine-medium conditioning and caffeine-conditioning-medium-exercise).Groups2to5for4weeks, caffeine dose200mg/kg orally and group1receivedsame amount of distilled water.After 6weeks, conditioned medium Sertoli cells was injected into efferent ducts mice in treatment group.After 8weeks of media conditioning injection and moderate aerobic training(60minutes,1bar per day¸5days per week),blood was collected from all mice and testes¸ epididymis were isolated.Then the blood samples were centrifuged at speed of3000rpm,at temperature40degrees Celsius for15minutes,and highly soluble serum was used measure testosterone hormone by radioimmunoassay method.In study the histopathology of testis samples fixed in10% formalin,5micron thick sections were prepared according to method of preparing tissue sections for hematoxylin-eosin staining.prepared tissue sections were examined for histopathology. In group under influence of caffeine, level of testosterone decreased significantly compared to control group(p<0.05).In both caffeine-media conditioning group and caffeine-exercise group, level of testosterone increased significantly (p<0.05).In caffeine-media conditioning-exercise group, level of testosterone hormone shows significant increase compared to previous2groups(p<0.05).In histopathological observations, testicular tissue in caffeine-damaged group has severe changes in germ cells and stop spermatogenesis,reduction germinal epithelium layers,edema, severe hyperemia and bleeding in interstitial space,irregularity of overlying epithelium,changes in thickness and irregularity in basal layer and irregularity,wrinkling and disintegration of structure of tubules,in many ducts.It was sperm maker. significant improvement was observed in caffeine-media conditioning-exercise group and tissue structure of testicles was relatively normal or close to normal. Consuming conditioned media of Sertoli cells and performing aerobic exercise at same time improves testosterone hormone indices and reduces harmful effects of caffeine on testicular histopathology of rats.

Weightlifting is a sport in which muscle strength plays an important role. Athletes use ergogenic aids to increase their muscle strength. Among supplements that improve strength performance of athletes are caffeine & arginine alpha glutarate. aim of present study was to investigate effect of acute caffeine and arginine alpha-actoglutarate consumption on the performance of elite weightlifters.

10 elite weightlifters participated in a crossover design that was implemented in four phases, one week apart. The subjects were selected by purposive sampling. In first week, one hour before performing the exercises, they consumed a placebo of 5 mg per kilogram of body weight. In second week, one hour before training, they consumed 5 mg of caffeine per kilogram of body weight. In third week, 4 grams of arginine alpha actoglutarate was consumed one hour before. In the fourth week, they took caffeine and arginine alpha-actoglutarate supplements one hour before. data were analyzed by repeated analysis variance and Bonferroni's post hoc test at a significance level of P>0.05.

The findings of the present study showed that in the comparison of three types of interventions, consumption of AAKG compared to caffeine ((P=0.002)) and the combination of caffeine and AAKG had a significant decrease in movement (P=0.01). In the comparison of three types of intervention, the consumption of AAKG compared to caffeine (P=0.001) and the combination of caffeine and AAKG had a significant decrease in movement two times (P=0.023)

weightlifting athletes can use caffeine and arginine alphaglutarate supplements to improve their performance

The purpose of this research was to determine the effect of different doses of caffeine chewing gum on stress hormones and shooting performance of military men. The subjects of the present research were 10 commanders of Valiasr Police Training Center in Tabriz with a mean and standard deviation of age of 31.52±2.78 years, weight of 75.32±3.91 kilograms, His height was 176.14 ± 4.84 cm. The levels of cortisol, adrenocorticotropic hormone and oxytocin in the blood as well as shooting performance were measured after consuming different doses of caffeine. In the first phase, the placebo was given 15 minutes before the shooting. In the second, third and fourth stages (the time interval between each stage is 5 days), all the subjects were given caffeine gum with doses of 150, 200 and 300 mg 15 minutes before the shooting. Gum and placebo were given to the participants in a double-blind manner. Descriptive statistics, analysis of variance with repeated measures and Tukey's post hoc test were used to analyze the data(P≤0.05). The results of the present study showed that the consumption of caffeine gum in doses of 200 and 300 grams causes a significant decrease in all three stress hormones and also a significant increase in shooting performance, however, the consumption of a dose of 150 mg of caffeine don’t have an effect on the reduction of stress hormones and Shooting performance. According to these results, shooting athletes can be advised to use caffeine gum with doses of 200 and 300 mg before their training and competitions. However, more studies are needed to comment on the use of different doses of caffeine, especially in the form of chewing gum.

Many scientific studies have provided evidence supporting the positive impact of caffeine on physiological performance, leading to its increasing use by coaches and athletes. However, it is important to acknowledge that caffeine usage can also have adverse effects on athletes. With this in mind, the objective of this research was to explore an alternative solution - the application of caffeine mouth rinsing - and its influence on agility, jump height, service accuracy, and spike accuracy among male volleyball players. To accomplish this, a group of 12 male volleyball players, aged between 18 and 25, was selected for the study. In the initial session, the experimental group, consisting of six individuals, applied caffeine mouth rinse (for 20 seconds before the game), while the control group, also comprised of six individuals, utilized water and flour nasal inhalation. The participants underwent Sargent tests, T-tests, long jumps, service accuracy evaluations, and spike accuracy assessments. Following a one-week interval, the next session took place, during which the control group replaced the experimental group. The findings indicated that caffeine mouth rinse exhibited a positive impact on explosive power and improved agility (p > 0.05). Furthermore, the results revealed a favorable effect of caffeine mouth rinse on both service accuracy and spike accuracy (p > 0.05). Based on these outcomes, it appears that caffeine mouth rinsing holds promise in enhancing the performance of male volleyball players.

Caffeine is a widely used physiological stimulant worldwide that athletes use to increase strength and delay fatigue, which is currently available in the form of energy drinks and dietary supplements. Therefore, the present study was conducted to investigate the effect of fatigue and caffeine supplementation on balance and some physical and skill fitness characteristics of young football players in Sarayan city.

In this way, 24 football players with an age range of 18 to 25 years, at least four to five years of continuous activity were purposefully selected and randomly divided into experimental and control groups. All participants firstly performed the dynamic balance, explosive power (Sargent jump test), agility (Illinois test), and Moore–Christian shooting & passing performance test. Further, the experimental group received caffeine capsules (six mg/kg/day) and the control group received starch capsules (six mg/kg/day). Moreover, the Bangsbo protocol was performed with 42 of two-minute cycles to create simulated fatigue in football players. After the implementation of the fatigue protocol and similar to the pre-test, all the tests were repeated. The results were extracted using independent and dependent t-test at the significant level of p≤0.05.

Muscle fatigue significantly decreasing effect on dynamic balance (p=0.001), vertical jump (p=0.001), shooting skill (p=0.001), but no significantly changes were observed on agility (p=0.39) and passing skill (p=0.11), while caffeine had no effect on these changes.

Consumption of six mg per kg of body weight caffeine may not have been effective and therefore, it seems that football players can improve their physical fitness characteristics from higher doses of caffeine instead of lower doses to be more effective. Further studies are needed to reach a definitive conclusion.

 Proteins such as p38α and HSP70 are considered as potential factors for type 2 diabetes disorders treatment. The aim of this study was to evaluate eight weeks of High-intensity Interval Training and caffeine consumption on p38α and HSP70 protein expression in the liver of diabetic rats.

50 male Wistar rats with an age range of 2-3 months were randomly divided into 5 groups of 10 rats in each group: Healthy control (C), Diabetic control (D), Diabetic with Training (D+T), Diabetic with Caffeine treatment (D+CA), and Diabetic with Training and Caffeine treatment (D+ T + CA). The training program consisted of 8 sessions and 5 sessions per week (6 to 12 2-minute sessions with an intensity of 85-90% of maximum speed) and 70 mg / kg of Caffeine soluble with saline was injected every day for five days. Western blotting was used to evaluate p38α and HSP70 proteins. Data were analyzed using two-way analysis of variance and if a statistically significant difference was observed, Turkey test was used to determine the location of intergroup differences.

 HSP70 protein levels were significantly different in healthy and diabetic mice. High-intensity Interval Training and caffeine consumption significantly increased HSP70 protein compared to the supplement + diabetic group (P=0.001). exercise + supplement group had a greater effect on increasing p38α than other diabetic groups, but this difference was not significant (P=0.96).

 High-intensity interval training and caffeine can play an effective role in counteracting damage of diabetes by increasing the expression of HSP70 in the liver.  However, high-intensity Interval Training and caffeine consumption have no effect on p38α expression in the liver of diabetic rats.

Chronic inflammation as an integral part of cardiovascular disease is associated with endothelial dysfunction. The aim of this study was to evaluate the effect of pre-intensive aerobic workout caffeine-beetroot supplementation on indicators related to vascular function including endothelial selectin (E-SELECTIN), growth differentiation factor-15 (GDF-15) and tumor necrosis factor-alpha (TNF-α) in elite  endurance runners.

In this experimental study, 10 elite male runners (age: 27.5±3.8 y, height: 176.7±7.8 cm, BMI: 22.3±1.5 kg/m2 and VO2max 52.2±4.6 ml/kg/min, were selected and with a double-blind, counterbalance, crossover and randomized design, were participated into three short-term conditions with 2 week washout. 1: high dose (9.6 mmol nitrate and 400 mg caffeine), 2: low dose (4.8 and 200) and 3: placebo. Subjects consumed 250cc of the supplement twice daily. Aerobic exercise included 5-km high intensity indoor running.

intervention, conditions and time effects with MANOVA repeated measures and bonferroni statistical analysis tests showed that the short term beetroot-caffeine supplementation (intervention effect) had no significant effect on E-SELECTIN and GDF-15, but decreased TNF-α (p=0.038). Also, that increased the GDF-15 (p=0.024), TNF-α (p=0.0001) and E-SELECTIN (p=0.047) and the supplementation after seven days (time effect) decreased the levels of TNF-α (p=0.033), GDF-15 (p=0.021) and E-SELECTIN (p=0.004) following exercise. 

an increase in the variables after exercise and decrease after seven days of the supplementation, indicates that may improves cardiac dysfunction caused by intensive aerobic exercise.

Background & Intense and prolonged physical exercise can lead to oxidative stress. Therefore, many supplements can prevent exercise-induced oxidative stress. The aim of this study was to investigate the effect of short-term supplementation of caffeine-beet juice on antioxidants and exercise performance in endurance athletes.
This study was performed in a short-term, counterbalanced, double-blind, cross-over and randomized study that included 7-day supplementation-placebo. Ten male runners (age: 27.5±3.8, weight: 69.9±7.8, height: 176.7±7 were divided in: 1-placebo [PLB] (beetroot juice without nitrate); 2- low dose beetroot juice [BRJ] (140ml BJ+4.8mmol nitrate+200mg caffeine); 3- high dose BRJ [BRJX] (140ml beet juice+9.6mmol nitrate+400mg caffeine). These supplements were taken with 250ml of water twice a day. The Trials were performed during 8 days with 14 days washout. Exercise protocol included 5km running with maximal effort.
The results showed that BRJX supplementation caused a significant increase in antioxidative enzymes (SOD, CAT, GPx) (p<0.05). Also, high and low doses of supplementation had a significant effect on endurance performance (p<0.05).
It can be concluded that high and low doses beetroot-caffeine juice supplementation has a beneficial effect on antioxidants enzymes and exercise performance in endurance athletes. Therefore, it is recommended to use this supplement before endurance exercise to prevent exercise-related oxidative damage and faster reduction of blood lactate and improve performance.

Inhibitory and activating mechanisms of interventions such as high intensity interval training and caffeine administration on major pathways of programmed cell death (apoptosis and autophagy) are not well understood. The aim of present study was to evaluate the effects of high-intensity interval training along with caffeine administration on Beclin-1 and Bcl-2 proteins expression in myocardium muscle of type 2 diabetic male rats.

In the present experimental study, 50 male white Wistar rats with an age range of 2-3 months were randomly divided into 5 groups of 10 rats in each group: Healthy control (C), Diabetic control (D), Diabetic with Training (D+T), Diabetic with Caffeine treatment (D+CA), Diabetic with Training and Caffeine treatment (D+T+CA). Western blot analysis was used to evaluate the cardiac muscle proteins (Bcl-2/Beclin-1).

The protein expression level of Beclin-1 was more than the C group, in D group; 201%, D+CA group; 215% and in D+CA+T group; 199% in compared to B-Actin (P=0.001). The Bcl-2 protein expression level in the experimental groups were significantly lower in comparison to the C group (P=0.001, F=73.83). As the expression level of this protein was significantly lower at around 37% in the D group compared to the C group (P=0.001). Whereas the Bcl-2 protein expression levels was significantly lower in the D+CA group and D+T+CA group compared to the C group at about 64 and 70 percent, respectively (P=0.001).

The results indicate that performed high-intensity interval training is effective in modulating the overexpression of Beclin-1 autophagic index and improving expression of Bcl-2 anti-apoptotic index. However, caffeine supplementation alone and along with high-intensity interval training were not effective in modulating of autophagic protein and improving anti-apoptotic protein.

the effect of resistance and aerobic exercise on improving the metabolic conditions of obese people has been confirmed; But the question of whether consuming energy supplements along with exercise improves the metabolic status and blood lipid profile of individuals is a new approach that has been considered. The aim of this investigation was to study the interactive effect of ten weeks of simultaneous training (resistance-aerobic) and mix supplementation (L-carnitine-caffeine-arginine) on lipid profile and leptin and adiponectin levels in obese men.

in this quasi-experimental and applied study with pretest-posttest design performed on non-athletic obese men, 28 subjects (age: 37.02±3.89yr, height: 174.7±6.57cm and BMI: 34.4±1.24kg/m2) were selected and randomly divided into three groups: 1): resistance-aerobic training and mix supplementation [RAS] (n: 10), 2): resistance-aerobic training and placebo [RAP] (n: 9) and 3): supplementation/detraining [HUS] (n: 9). The mix supplement contained 200mg of caffeine, 1000mg of L-carnitine, and 1000mg of L-arginine taken 40min daily before exercise. Resistance and aerobic trainings were included 30min and 40-45min respectively with moderate intensity for ten weeks and 3d/w.

the findings showed that mix supplementation (L-carnitine-caffeine-arginine) with moderate intensity resistance- aerobic training had a significant effect on decrease of plasma leptin (p=0.0001) and increase of adiponectin (p=0.001) levels. Also, the interaction of resistance- aerobic training and mix supplementation in decreased TC, TG and LDL-C levels and increased HDL-C (p<0.05) in non-athlete obese men.

it can be concluded those ten weeks of mix supplementation (L-carnitine-caffeine-arginine) and moderate intensity resistance-aerobic exercises had a positive effect on metabolic markers and blood lipid profile in non-athletic obese men.

Some studies have studied the effect of insomnia on the performance of athletes. However, no research was found to investigate the effect of caffeine supplementation after 24-hour sleep deprivation. Therefore, the aim of the present study was to investigate the acute effect of caffeine consumption following 24 hours of sleep deprivation on the muscular and physiological performance of handball players.

In this double-blind and semi-experimental study, 40 male handball players (average age: 17.66±3.36 years, height: 179.47±7.29 cm, weight: 82.27±14.04 kg), were randomly divided into four groups (10 people in each group): caffeine supplement + sleep deprivation, placebo + sleep deprivation, insomnia group and complete sleep group. The supplement group took caffeine capsules (5 mg per kilogram of body weight) and the placebo group (starch powder) one hour before the test. One-way ANOVA statistical test was used to compare the significance level (P≤0.05) between groups.

24 hours of sleep deprivation had no significant effect on abdominal muscle endurance and flexibility (P≤0.05). However, sleep deprivation caused a significant decrease in the strength, power and muscular endurance of the subjects' shoulder girdle (P≥0.05). Also, consuming caffeine after 24 hours of sleep deprivation improved muscle strength and power in the supplement group compared to the placebo group (P≥0.05). However, there was no difference between the muscle endurance of the caffeine group and the placebo group (P≤0.05).

According to the results, it can be stated that the physical and physiological performance is disturbed due to the combination of mental pressure caused by insomnia and stress caused by sports activity. Therefore, it is suggested to use caffeine supplement to compensate for insomnia and improve performance.

In recent years the consumption of energy drinks has increased dramatically, especially among athletes. Athletes believe that consuming energy drinks increases their performance due to their ergogenic compounds such as sugars, caffeine and taurine. The age range was 16 to 18 years. The statistical population of the study was 60 male high school students in the third grade of the Malard School of Physical Education, out of which 24 volunteers with the same weight (between 68 and 72 kg) were selected. Participants were randomly assigned to three groups: consumption of 250 ml hype drinks with caffeine (32 mg per 100 ml), placebo and baseline conditions. Interventions were applied for 3 weeks. In the present study, Wall Sit test was used for fatigue. Then, perception of stress through Borg index and mood status was assessed by Broms Questionnaire in two stages of pretest and posttest. The results of Friedman test and repeated analysis of variance showed that consumption of hype drinks significantly reduced perception of stress and temperament in adolescent basketball players. As a result, energy drink hype can be effective in reducing perception of stress and improving mood in adolescent basketball players. The present study also showed that perception of placebo (effect of placebo) can be effective in reducing perception of stress and mood.