نشریه پژوهش در تغذیه ورزشی
پیاپی 3 (پاییز 1401)

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.

This study aimed to investigate the effects of aerobic training and a high-fat diet on the expression of Kiss1 and Kisspeptin receptor mRNA in the testes, and levels of LH and FSH in adolescent male rats. Forty young male rats (30 days old) were randomly assigned to one of four groups: normal diet control (NDC), normal diet training (NDT), high fat diet control (HFDC), and high fat diet training (HFDT). The rats in the HFD groups were fed a high-fat diet (5.817 kcal/g) for 30 days, while the normal diet (3.801 kcal/g) was continued until the 60th day of their life. Aerobic training was carried out for four weeks and involved three training sessions from the 70th to 98th days of their life. The results showed that high-fat diet caused a significant decrease in kisspeptin and gonadal kisspeptin receptor content of male rats, and exercise also increased them. Also, the high-fat diet caused a significant decrease in the amount of LH hormone in the blood of male rats, and exercise also increased it. Exercise training increased circulating FSH and high-fat diet decreased FSH in male rats. Overall, the results showed that a high-fat diet decreases the amount of kisspeptin and its receptor in the testicles of rats along with a decrease in circulating FSH and LH hormones. On the other hand, aerobic exercise has completely opposite effects to a high-fat diet; However, it is only partially able to compensate for this negative effect caused by a high-fat diet, and in any case, it is not able to eliminate all its bad effects.

Choosing the appropriate method to achieve the ideal weight has a significant impact on the performance of wrestlers. Therefore, the aim of this study was to compare the effects of three rapid weight loss methods on some indices of physical and motor fitness in elite male wrestlers. Twenty-four elite male wrestlers (age: 21.91±2.04 years; weight: 68.55±6.1 kg) were voluntarily selected and divided into three homogeneous groups (n=8), including training with plastic suits, dry sauna and complete diet restriction. Subjects in each group lost about 3 percent of their body weight through rapid weight loss. Body composition, indices of physical and motor fitness, including upper and lower body muscle strength, cardiovascular endurance, agility and flexibility were assessed before and two hours after weight loss. Paired t-test and one-way ANOVA were used to analyze the data (P<0.05). The results of the present study showed that all three methods of rapid weight loss significantly reduced upper body muscle strength (respectively for plastic suits, sauna and diet restriction: P=0.02; P=0.04; P=0.0001), lower body muscle strength (P=0.007; P=0.009; P=0.002) and cardiovascular endurance (P=0.03; P=0.01; P=0.001) in wrestlers. In this regard, the rate of loss of upper body muscle strength (P=0.027) and cardiovascular endurance (P=0.041) in wrestlers when using the complete diet restriction method was significantly higher than the other two methods of rapid weight loss. In general, it seems that wrestlers should avoid the complete dietary restriction method if necessary to rapid lose weight and use other methods, especially training with plastic suits.

Considering the role of physical activity on factors affecting metabolic diseases, the aim of this study is to investigate the effect of moderate intensity aerobic exercise and zinc supplementation on tumor necrosis factor alpha (TNF-α) and interleukin 1 beta in women with diabetes. It was type 2. Research In this semi-experimental study, 50 women with type 2 diabetes with age range (age 8±35 years, height 162±1.5.3 cm, weight 87.67±4.3 kg, body mass index 31.12±3.6 kg/m2) who had no regular activity were selected as research subjects and were randomly divided into four groups: exercise, exercise-supplement, zinc supplement and control. Fasting blood samples were collected before and after 12 weeks of training. One-way analysis of variance was used to analyze the data. SPSS version 22 software was used for data analysis. The results of this research showed that after 12 weeks of aerobic training with moderate intensity, there was a significant difference in the level of interleukin 1 beta (p=0.001), TNF-α (p=0.001), in the experimental and control groups. Was. The results of this research showed that taking zinc supplements along with moderate and combined aerobic exercises can reduce the levels of interleukin 1 beta and tumor necrosis factor alpha, so it can be used as a therapeutic and complementary method. It should be considered for patients with type 2 diabetes

Engaging in exercise increases mitochondrial oxygen consumption, leading to a higher production of free radicals. Given L-arginine's role in boosting the immune response and mitigating the impact of free radicals, this study examined the influence of eight weeks of endurance training along with L-arginine supplementation on GPX and TAC levels in the gastrocnemius muscle of male Wistar rats. The study involved 32 male Wistar rats, aged eight weeks, randomly assigned to four groups: control, exercise training, L-arginine, and exercise training + L-arginine.The training regimen entailed 8weeks of endurance training on a treadmill. The supplement and training+supplement groups were given four grams of L-arginine in 100ml of water. All rats were dissected 48hours after the final training session and after eight hours of fasting. The quadriceps muscle was isolated from the samples, and the GPX and TAC enzyme activities in the skeletal muscle were measured using the spectrophotometric method. Data were analyzed using a one-way analysis of variance test with a significance level set at p<0.05.The study results indicated that the GPX levels in the skeletal muscle of the exercise training+supplement group were significantly higher than those in the training group(p=0.001). However, there was no significant difference in the TAC levels in the skeletal muscle across the study groups (p=0.836). Given the positive impact of L-arginine supplementation alongside intense endurance training on increasing GPX enzyme levels, it's likely that L-arginine supplementation could help prevent the decline of GPX enzyme levels and associated complications during intensive endurance training.

Lemongrass (Melissa officinalis) has an effect on the nervous system, causing relaxation and an important role in modulating the inflammatory condition. The aim of present study was to examine the effect of Melissa Officinalis L. extract supplementation on eccentric training induced muscle damage response and perceived pain.Materials: In this experimental study, sixteen healthy middle-age men (20 – 35 years of old) were divided into placebo (Plc) or supplement (S) group randomly according their muscle strength. Subjects in the S group consume 1.5 mg/kg of Melissa Officinalis L. extract for 14 days while subjects in the Plc group consume same dosage of dextrose. Then, all the subjects performed eccentric biceps curls with 120% of their 1RM on two occasions. Blood sample were taken before and after the supplementation and immediately after the eccentric training. Data were analyzed using repeated measure ANOVA and Bonferroni post hoc test. The study results indicated that LDH increased in Plc group after the eccentric training (p=0.01). Blood CK had not significant change after the intervention in both groups and perceived pain was increased in both groups (p=0.01). In summary, it seems that Melissa Officinalis L. extract supplementation can be considered as an effective way to reduce intense exercise induced-muscle damage, but more research is needed to draw definitive conclusions.