Effect of milk consumption on healthy young men rehydration and endurance performance after dehydration due to intermittent exercise in warm environmental condition

Background and Objective: Rapid and adequate rehydration is important for many athletes, especially those taking multiple sessions of exercise each day, or those involved in weight category sports. The macronutrient and electrolyte concentration of the fluid ingested following exercise can affect the amount retained within the body can influence hydration status. This study was done to compare the effect of milk consumption on healthy young men rehydration and endurance performance after dehydration due to intermittent exercise in warm environmental condition

Methods: In this quasi-experimental study, the labroratory protocol was carried out by ten young healthy men in three sessions within one week intervals. Participants were on drinking regiment including water, low-fat milk, and powerade. Urine samples were collected pre-exercise, post-exercise, post-drinking and 1, 2 and 3 hours over recovery. Exercise capacity test commenced within 10 min after 3h recovery. This was undertaken in warm environmental condition at a power output corresponding to 70% V02 max. Exercise continued until voluntary exhaustion. Heart rate and RPE were recorded at 5 min intervals throughout exercise

Results: Pre-exercise urine specific gravity value was not different between the milk and the, powerade and the water groups. Total urine output was significantly reduced in the milk group in compared to powerade and the water consumption [P<0.05]. At the end of the study, net fluid balance was significantly positive in milk group compared to powerade and water groups [P<0.05]. Time of exhaustion on the exercise capacity test [70% V02 max] was significantly more in milk in comparision with powerade group [P<0.05]

Conclusion: Low-fat milk is more effective at rehydrating compared to water and exercise capacity in intermittent activity of heat in healthy young men

effect of 12 weeks aerobic exercise on DHEAso4, 17OH-Progestron concentrations, number of follicles and menstrual condition of women with PCOS

The effective method of treatment of Polycystic Overy Syndrome [PCOS] is lifestyle modification. The aim of this study was to evaluate the effect of 12 weeks aerobic exercise on DHEAso4, 17OH-Progestron Concentrations, number of follicles and menstrual condition of women with PCOS. In this clinical trial, 40 PCOS patients lean [BMI<20] and obese [BMI>25] randomly divided into two trained and sedentary control groups. DHEAso4, 17OHProgestron Concentrations, number of follicles and menstrual condition were measured before and after the program [12-week exercise training program, aerobic exercise at 60-80% of maximal heart rate, 25-30 min/day, 3 days/week]. Decline of DHEAso4, 17OH-Progestron Concentrations were significant after exercise in obese group [P=0.023, P<0.0001]. The number of follicles right and left ovaries decreased significantly after exercise in two groups lean and obese [Right; P=0.019, P=0.041 and Left ovary; P=0.005, P=0.008]. Menstrual situation was improved after exercise in obese and lean groups [P=0.028, P<0.0001]. The body weight decreased significantly after exercise in obese groups [P<0.0001]. It seems that a term of exercise with weight loss can induce decline of DHEAso4 and 17OH-Progestron. In addition, exercise lead to improved menstrual condition and reduction of number of ovarian follicles per groups of lean and obese

[Effect of Zinc supplementation on serum testosterone and plasma lactate in male cyclist after one bout of exhaustive exercise]

There is fairly scarce information about the effects of zinc, an essential trace element, on exercise performance. Studies concentrate mostly on the distribution of this element in the body in response to exercise. The purpose of this study was to investigate the effect of exhaustion exercise on the testosterone levels and plasma lactates in road cyclists who are supplemented with oral zinc for 4 weeks. In this semi experimental sixteen male road cyclists, who were healthy in the first evaluation were selected from the Tehran traffic team and were divided into two groups according to mass body index; zinc group and control group. After 4 weeks zinc supplementation [30 mg/day], blood samples were collected from each subject before and after an exhaustive exercise bout. Data were analyzed by independent and paired sample t test. Total testosterone, free testosterione and lactate levels in two groups were increased by exercise [P<0.05] and there was no significant differences between total testosterone and lactate levels in two groups before and after exhaustion exercise [P>0.05]. There was a significant difference between effects of exhaustion exercise on free testosterone levels between two groups [P<0.05]. According to this study, zinc supplementation has no significant effects on testosterone and lactate levels in response to exercise in subjects with a balance diet. However, free testosterone levels were increased by exercise after zinc supplementation

[Effect of zinc and selenium supplementation on serum testosterone and plasma lactate in cyclists after one bout of exhaustive exercise]

Introduction: The purpose of this study was to investigate how exhaustion exercise affects testosterone levels and plasma lactates in road cyclists supplemented with oral zinc and selenium for 4 weeks

Materials and Methods: Twenty-four male road cyclists volunteers, were selected from the Tehran Traffic team, and based on BMI were divided into three groups; the selenium, zinc, and controls. The status of zinc and selenium in subjects was assessed at baseline. After 4 weeks of supplementation free, total testosterone, and lactate levels of all subjects were determined before and after exercise. Data was analyzed according to repeated measures ANOVA, and the Bonfferoni post hoc test, with a significance level of P<0.05

Results: Resting total, free testosterone, and lactate levels did not differ significantly between groups, and were increased by exercise [P>0.05]. Total testosterone levels in the Zn group were higher than in the Se group after exercise [P<0.05]. Free testosterone levels in the Zn group were higher than the other groups [P<0.05]. There was an insignificant difference between levels of lactate in the three groups after exercise [P>0.05]

Conclusion: According to this study, 4-week selenium and zinc supplementation had no significant effect on testosterone or lactate levels of subjects who had a zinc and selenium sufficient diet. Zinc supplementation increased levels of total testosterone in contrast with selenium group, and also increased free testosterone versus the other groups, whereas there was no change in the levels of lactate in the three groups post-test

[Effects of aerobic training with low and intermediate intensity on appetite, body weight, exercise energy expenditure and plasma ghrelin level in relatively thin and obese sedentary women]

The objective of this study was to compare the effects of 8 weeks of aerobic exercise with low and intermediate intensity on appetite, body weight, exercise energy expenditure, and plasma ghrelin level in women. Sixteen relatively obese [BMI>28] and 14 relatively thin [BMI<22] volunteer female-subjects were divided randomly into four groups, including obese with low intensity exercise [age=45.75 +/- 6.75 years, BMI=29.21 +/- 0.50 kg/m2]; obese with moderate intensity exercise [age=47.12 +/- 4.12 years, BMI= 29.59 +/- 0.127 kg/m2]; thin with low intensity exercise [age = 8 +/- 4.65 years, BMI = 21.21 +/- 0.53 kg/m2]; and thin with moderate intensity [age = 38.125 +/- 2.53 years, BMI= 21.49 +/- 0.377 kg/m2] exercise. Both the thin and obese groups with low intensity exercise ran 30 minutes per session [3 sessions/wk] for 8 weeks by 50% of the Maximum Heart Rate [MHR]. The intermediate exercise counterparts did the same exercise by 60% of MHR. Body weight at the beginning of each session and the distance run were recorded in each session. The Visual Analog Scale-based appetite questionnaires were filled in the morning of the 1st session of the first and fifth weeks and also in the morning of the day after the final session of the 8th week of the training; in all cases blood samples were taken to measure plasma acylated ghrelin level. The statistical tests used for data analysis included one-way ANOVA, ANOVA for repeated measurements, pair t-test, and partial Pearson correlation at 0.05 significance level. In all groups, feeling of hunger and plasma acylated ghrelin level increased, while body weight and satiety decreased [P<0.05]. There were significant differences in the magnitude of changes in hunger and satiety among the groups between the 4th and 8th weeks of exercise [P<0.05]. The distances run in each group between the 4th to 8th weeks were longer than those run in first 4-week of exercise [P<0.05]. The distances run by the thin groups in both the 1st and 2nd 4-week periods were longer than those run by the obese groups [P<0.05]. The data also showed that both the thin groups' exercise energy expenditures were higher than those of the obese groups between the 4th and 8th weeks of the training [P<0.05]. A statistically significant correlation was observed only in the thin group with low-intensity exercise between the body weight changes and hunger changes by the end of the 8-week period and between the aerobic exercise energy expenditure and the acylated ghrelin level changes between the 4th and 8th weeks [P< 0.05]. Moreover, there was a significant correlation between the distance run and changes in the plasma acylated ghrelin level between the 4th and 8th week of the training only in the thin group with moderate-intensity excercise [P<0.05]. It is unlikely that the aerobic exercise intensity or obesity/thinness would be the only effective factors on appetite in women. It seems moderate-intensity exercise would be preferential in weigh loss programs because of its higher energy expenditure. Additionally, it is expected that moderate-intensity exercise would give better results also in body weigh gain programs due to smaller increases in a feeling of hunger in thin individuals with low-intensity exercise. However, since true energy intake was not measured in this study [and considering lack of evidence in this area], longitudinal studies are needed to throw more light on the subject