[The effect of interval exercise in hypoxia on responses of PYY[3-36] and appetitein overweight individuals]

Introduction: since obesity and overweight have dramatically increased in recent years, the purpose of this study was to compare the effects of hypoxia on responses of PYY3-36 and the appetite to interval exercise among overweight individuals

Materials and Methods: eight healthy male subjects [age, 22.14+/-2.11 yrs; height,175.28+/-7.69 cm; weight, 87.03+/-5.95 kg; BMI, 28.4+/-1.5 kg/m2] voluntarily participated in the study and performed an exercise protocols [cycling] in noromxic and hypoxic conditions on two separate sessions [Counterbalance] with a one week interval. Interval exercise included 5 repetitions of 4-min activity at 85%of HRmax, followed by 2-min active restat 50% of HRmax. The environmental and training conditions were kept constant in two sessions, with the exception that the interval exercise was performed with 15% reduction in oxygen partial pressure in a hypoxic trial. Blood samples were taken before and after exercise [10, 20, 40, 60 and 80 minutes] and were analyzed for measuring the PYY3-36 using the ELISA technique

Results: environmental conditions did not induce significant effect on PYY3-36 responses to interval exercise [P=0.1], though, exercise increased the PYY3-36, especially in normoxic conditions. In addition, although there was a reduction in the appetite following the two trials, environmental conditions had no significant effect on appetite [p=0.872]

Conclusion: interval exercises increase circulating levels of PYY3-36 and reduce appetite, irrespective of the environmental conditions [normoxia or hypoxia] in which the exercise is performed

[Effects of different types of isokinetic contraction on hemodynamic parameters in men]

The purpose of this study was to compare the effect of different types of isokinetic contractions on hemodynamic parameters in men. Ten healthy male subjects [age, 26.1 +/- 3.4 years] in three separate sessions performed three exercise protocols included Concentric/Concentric [C/C], Eccentric/Eccentric [E/E] and Concentric/Eccentric [C/E] contractions [flexion and extension] in the knee joint. In each session subjects performed 4 sets, 10 repetitions, at the speed of 60 degree per second. Hemodynamic parameters [heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and rate of pressure product] were measured before exercise, immediately after exercise and after 30 min recovery. Data were analyzed using two- way repeated measures of ANOVA. Statistical analysis of data showed significant increases in heart rate, systolic blood pressure [P<0.001], mean arterial blood pressure [P=0.053] and rate of pressure product [P<0.001] during exercise and significant reductions in these parameters in recovery period. Rate of perceived exertion [RPE] was significantly different among the contraction protocols [F[2,34]=15.5] and post-hoc test showed that RPE was lower in E/E protocol than the other two protocols. Hemodynamic parameters change in response to different muscular contractions, though these changes are not related to contraction type

[Effect of upper and lower body exercises on cardiovascular, metabolic and hematologic factors]

Considering the sophisticated responses of cardiovascular system to different types of body exercises, dealing with this system and the effect of exercise on it has assumed an added importance. The aim of this study was to compare the effect of two types of exercise, arm cranking and leg cycling, on cardiovascular, metabolic and hematologic factors. After obtaining informed consent 10 non athlete female students with a mean age of 25 +/- 2.69 years and mean height of 161.75 +/- 5.5cm participated in this study. They completed four experimental testing sessions [two maximal oxygen consumption test on a cycle ergometer and arm cranking to assess variations in respiratory gases and heart rate by using ergometer cycling and arm cranking vO[2]max, and two sub-maximal exercises including warm up for 5 minutes and body exercise on cycle ergometer or arm cranking with 70% of maximum O[2] consumption or 75-80% of maximum heart rate, for 30 minutes. Then the subjects took a 30 min rest in the sitting position. Heights and weights of the subjects were measured before exercise. Before and after exercise and after 30 min rest in sitting position, heart rate and blood pressure were recorded and blood samples were collected for measurement of blood lactate concentration, RBC, Hb, Hct, MCV, MCH and MCHC. No differences were found between the two types of exercises in regard to the HR, RBC, Lac, HG, Hct, MCV and MCHC but there were significant differences in relation to BP and MCH [P=0.013 and f[1.9] =9.385 for blood pressure; P=0.046 and f[1.9]=5.372 for MCH]. The results indicated no differences in the cardiologic, hematologic and metabolic factors during exercises with similar relative intensity. But we found a higher BP after arm cranking and an increase in MCH after leg exercise. Also, there were significant differences in all parameters except HG and MCH, before and after exercise

[Effects of Ramadan fasting and regular exercise training on fat and CHO metabolism]

The purpose of the present study was to investigate the combined effects of endurance training and fasting during Ramadan on fat and carbohydrate metabolism. Twenty four healthy men [age, 25.4 +/- 2.3 years] were randomly allocated to two groups of fasting [F, n=12] and fasting + endurance training [F+ET, n=12]. The study protocol for the F group included 10 and the F+ET group had 12 subjects. The fasting group only fasted during Ramadan, whereas the F+ET group, in addition to fasting, performed three sessions of endurance training on the treadmill after Iftar. Antropometric indices, blood samples and dietary intakes were documented the beginning of Ramadan and after the first week and at the end of Ramadan. Weight and body mass index did not change significantly during Ramadan in either group [P>0.05], but the body fat percentage reduced significantly [P<0.05] during Ramadan in both groups. Fat oxidation, carbohydrate oxidation, insulin, glucose, glycerol, and non-esterified free fatty acid changed in the first week of Ramadan, more pronouncedly in F+ET group, whereas in the F group these changes occurred more during the second half of the Ramadan, though the changes did not differ significantly between the two groups. Combining Ramadan fasting and exercise training affects the trend of changes in fat and carbohydrate oxidation during Ramadan. Generally however the effects of two protocols were similar and adding the endurance training to fasting did not induce more changes than fasting perse

[ effect of endurance training accompanied by fasting and a period of detraining on serum leptin and fructosamine in overweight men]

The purpose of the present study was to determine the effect of endurance training accompanied by fasting and a period of detraining on serum leptin and fructosamine in overweight men. Twenty-one healthy male subjects [Mean +/- SD; age 25.2 +/- 3.7 years; weight 78.3 +/- 12.7 kg; BMI 26,1 +/- 3.7] voluntarily participated in the study and were divided into the fasting [F] and endurance training+ fasting [F+ET] groups. The F+ET group performed a training program on treadmills for four weeks, 3 times per week during Ramadan. The energy expenditure in each exercise session during at the first week of Ramadan was 500 Kcal and increased to 800 Kcal per session by the last week of Ramadan. At the end of Ramadan, the F+ET group stopped training and fasting and underwent 2 weeks of detraining, and the F group returned to a normal diet during this period. Anthropometric characteristics were measured and three blood samples were taken before, at the end of Ramadan and after detraining. Data were analyzed by using repeated measures of ANOVA with a between group factor. The between-group comparison showed that changes in serum leptin and fructosamine were not significantly different between the two groups [p>0.05]. Furthermore, serum leptin and fructosamine levels did not change [within-group comparison] in the F and F+ET groups [p>0.05]. Based on the findings of the present study it could be concluded that compared to fasting per se, combining endurance training and fasting do not induce more changes in leptin and fructoseamine

[Effects of resistance exercise intensity on adipokines and insulin resistance index]

Adipose tissue secretes multiple proteins known as adipokines that modulate various biological functions. The present study was designed to determine the effect of resistance exercise intensity on leptin, adiponectin and the insulin resistance index in young healthy men. Fifteen healthy male subjects [Mean +/- SD; age 26.2 +/- 4.1 years; weight 75 +/- 9.1 kg; height 174 +/- 7.0 cm] voluntarily participated in the study. After two familiarization sessions and determining of maximal strength, all subjects completed three resistance exercise trials at an intensity corresponding to 30%, 55%, and 80% of 1-RM randomly. The three resistance exercise protocols included the performance of 1] 3 sets of 20 repetitions at 30% of 1-RM, 2] 3 sets of 11 equated for volume and one minute rest was allowed between exercises and sets. Two blood samples were obtained before exercise and immediately after exercise and analyzed for leptin, adiponectin, plasma insulin and glucose. To determine the effect of resistance exercise intensity, data were analyzed using two-way repeated measures of ANOVA. Data analysis revealed that resistance exercise increase adiponectin [F1, 12=47.2], insulin [F1, 11=19.7], glucose [F1,13=9.6], concentrations and the insulin resistance index, while reducing the leptin concentration [F1,12=31.1] significantly. However, resistance exercise intensity had no significant effect on any of the above variables [P>0.05] except for leptin concentration [F2,24=5.5, P=0.01]. Based on the findings of the present study it could be concluded that resistance exercise induces significant changes in adipokines and insulin resistance index but when the resistance exercise volume is equal, except for changes in leptin, these changes are not related to the intensity of exercise

Effects of stimulator substances on aerobic methyl tert-butyl ether biodegradation by microbial consortium

In this study dissolved humic substances and yeast extract were tested in different concentrations for enhancing methyl tert-butyl ether mineralization by isolated microorganisms from a variety of sources. All experiments were conducted at a constant temperature of 25?C. Vials of 50 mL and 125 mL volume sealed with Teflon-lined Mini-Nert caps was used for microcosm experiments. In all experiments 1% sodium azide were used as control. Samples of bacterial cultures that metabolize methyl tert-butyl ether have been analysed by direct GC analysis using flame ionization detector. Cultures able to metabolize have been found in activated sludge and soils. These microorganisms were gram-positive bacterium. An aerobic microbial consortium was enriched in laboratory for four months. Methyl tert-butyl ether has been shown to biodegrade under aerobic and co-metabolic conditions. A microbial consortium isolated from activated sludges was identified as Cocobacillus. The concentration of the initial attached biomass was about 0.11 g/L of dry weight. The maximum mineralization rate and beneficial effects of stimulator substances on aerobic biodegradation of methyl tert-butyl ether occurred with the culture by combined concentrations of 500 mg/L of yeast extract and 20 mg/L of peat humic growth support of microbial consortium within 216 h and in presence of high oxygen levels and well mixing conditions. It was shown that adding, peat humic and yeast extract together had better stimulatory effect on methyl tert-butyl ether biodegradation. Results clearly showed a stimulatory effect on methyl tert-butyl ether consumption higher than 20%. Consortium was capable of degrading concentrations of 1000 mg/L, were not degraded

[Study of the effective parameters on the making use of protective devices in Qom province workers community in 2006]

Noise threats health of many groups of industrial workers and causes hearing loss. Use of personal protective device is the best control method to protect against hazardous conditions. Hence, this investigation was carried out to determine situation of using of protective devices and effective parameters on it, in Qom province workers community in 2006. This research is descriptive-sectional study. Sample volume was designed 378 persons working in factories in Qom. First of all, list of Qom factories with noise pollution problems, were collected and 30 important factories among them were selected randomly. In the second stage, 378 persons were selected randomly from workers. The interest information was obtained by questionnaire and collected data were analyzed by SPSS software. The obtained results showed that, 83.6% of workers have been using ear protective devices. 296 of them, which were using ear protective devices, had an occupational hygienist in their workplaces. This research also showed that, 109 workers that used ear protective devices, had moderate knowledge level. Moreover, 82.5% of trained workers have used ear protective devices. The statistical analysis of the results showed that there were no significant relationship between use of ear protective devices and existence of occupational hygienist in workplace, knowledge and age of workers, worker's antecedent, physical health of workers and kind of ear protective devices [p > 0.05]. These results showed that among all considered parameters; only four parameters were effective in using ear protective devices; education of workers before employment, head workman and employer's knowledge level, factories facilitation and kind of ear protective devices