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Showing 5 results for Cortisol

Hamidreza Barzegarpoor, Hamid Rajabi, Saied Mohammadi, Rana Fayazmilani,
Volume 0, Issue 0 (11-2019)
Abstract

Performing a mental exertion during an exercise increase fatigue indices and the amount of fatigue seems to depend on the type of mental exertion. So, the purpose of the present study is comparing the effects of performing types of mental exertion during cycling exercise on fatigue indicators. Methods: 10 cyclist men with average peak power output 236 ± 36 W invited for 5 different sessions. In the first session, anthropometric characteristics and of cycling peak power output (PPO) have determined. In the next four sessions, cycling for 45-min at 65% PPO on the cycle ergometer with (Stroop, AX-CPT and PVT) or without mental exertion. Rate of perceived exertion (RPE) and heart rate were recorded while cycling every 10 min and cortisol concentration was measured before and 30 min after exercise finished. Two-way repeated-measures ANOVAs were used to analyzing data. Results: Performing 45 minutes of Stroop mental exertion during cycling exercise increased RPE and cortisol concentration compared to cycling exercise alone (P˂0/05) but there is no differences between AX-CPT and PVT to cycling exercise alone. Conclusion: The results of the present study showed that performing Stroop mental exertion during the cycling exercise than cycling exercise alone increase more the fatigue indices.
Dr Mohsen Mohammadnia Ahmadi, Mrs Razieh Heidari,
Volume 0, Issue 0 (11-2019)
Abstract

Nowadays, the use of traditional herbal remedies for the prevention and treatment of diseases along with exercise has become very popular. The aim of this study was to investigate acute effect of hydro alcoholic extract of melissa officinalis on metabolic rate, substrate oxidation and salivary cortisol during and after high-intensity interval exercise (HIIE) in inactive women. Ten inactive women in Birjand were selected based on criteria (age 24±6 years, BMI 22-23 kg/m2). Individuals participated in two separate sessions (one week apart). In the first session, hydro alcoholic extract of melissa officinalis supplements (500 mg) were intake one hour before HIIE. In the second session, the placebo (500 mg of starch) was intake. The HIIE program consisted of 11 alternates (1-minute with 90% vVO2max followed by 2-minute rest intervals with 60% vVO2max). Pre, during and after HIIE, oxygen consumption and carbon dioxide excreted by the breath was measured using the respiratory gas analyzer and was used to calculate metabolic rate (Energy Expenditure, VO2) and substrate oxidation (Fat oxidation, Respiratory Exchange Ratio (RER)). Salivary cortisol after collection was measured by chemiluminescence method. Repeated analysis of variance was used for statistical analysis of the data. Based on results, there was no significant difference in VO2 (P =0.51), Fat Oxidation (P= 0.9), RER (P= 0.76) and energy expenditure (P=0.6) between melissa officinalis and placebo intake. Also, there was no significant difference in salivary cortisol (P= 0.15). Generally, hydro alcoholic extract of melissa officinalis supplement intake along HIIE has no effect on metabolic rate, substrate oxidation and cortisol level in inactive women.
 
Dr Hamdollah Hadi,
Volume 0, Issue 0 (11-2019)
Abstract

Purpose: 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. 
Materials and methods: The subjects of the present research were 10 commanders of Valiasr Police Training Center in Tabriz who had participated in the shooting competitions of the armed forces, 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. On the first day of the research, the height and weight of all subjects were measured. 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)
Findings and results: 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.
Conclusion: 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.
 
Atefe Yar Ahmadi, Dr Mohammad Ali Samavati Sharif, Shima Eghbali Khosro, Poriya Hesari,
Volume 13, Issue 9 (4-2015)
Abstract

Introduction and aim: The aim of present study was to assess the effect of six weeks Badminton training
on changes of stress and cortisol levels in non-athletic female students. Materials and Methods: In this
study estimated stress of 120 non-athlete students by stress questionnaire (HAD scale). Were measured
Among subjects who had suffered highest stress, 30 subjects with a mean age of 86/2 ± 22 years, height
56/5 ± 163 cm and weight 95/4 ± 57 kg were selected. Cortisol were measured by the bloodletting. The
subjects were divided into two experimental and control groups as homogeneous. But the control group did
not perform any activity. After training protocol variables were measured again in the same conditions. To
estimate the effect of independent variables on the dependent variable of the t-test and the independent ttest
to compare groups with a significance level (p <0/05) was used. Data were analyzed using spss and
Excel software.
Results: The results of this study showed that doing a six-week badminton practice reduces cortisol levels
(p =0.005), and decreasing stress (p =0.03) in the experimental group.
Conclusion: There was significant change in levels of cortisol and stress in experimental group.


S Nezami, M.a Samavati Sharif, A Chezani Sharahi,
Volume 15, Issue 13 (9-2017)
Abstract

The purpose of the current study was the effect of 8-week high intensity resistance training (the Split training method), on Testosterone, Cortisol and Testosterone/Cortisol serum level and its influence on muscle mass and development of muscle strength. 20 persons beginner in bodybuilding (body mass index: 23.80±2.25 kg/m2; age: 24.65±2.55 year) participated in this study. The subjects divided randomly into strength training (10 persons) and control groups (10 persons). Training program was designed according to the Split method with 85%-100% of 1RM for six times per weeks. The same strength and duration was applied for the control group based on the traditional training. Before and after training the thickness of Triceps muscle was measured with ultrasound in both groups. Resting blood samples were collected before and after training. The results showed, compared with traditional training, training with Split method increased muscle strength (p=0.01), muscle mass (p=0.001) and the Testosterone to Cortisol (T/C) ratio (p=0.02). Moreover, there were significant correlation between the maximum strength and hypertrophy(r=0/55, p=0/001) and between (T/C) and maximum strength (r=0/74, p=0/03). The results of this study shows that resistance training with high intensity (the Split Training Method) causes increase in anabolic stimulation and muscle mass which subsequently increases maximum strength.



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