Background: Previous studies have suggested reduced fat metabolism in older subjects. However, corrections for their reduced maximal oxygen consumption and the effects of training and substrate availability have not been fully examined. Objectives: Fat metabolism (FM) in older subjects (n=14, 75±7 yrs), and the effects of exercise training were compared with FM in younger subjects (n=16, 22±3 yrs).Materials and Methods: All subjects completed a maximal exercise test and a sustained submaximal run at 70% of their maximal capacity. The RESPIRATORY EXCHANGE RATIO (RER) and blood substrate levels were determined. Older subjects were re-tested after training. Results: Young subjects had higher oxygen consumption (VO2) peak (36.3±6.7 vs. 23.7±6.2 ml/kg/min) and lower slope of RER vs. VO2 than older subjects. However, the slope of the RER vs. VO2 relationship was not different between younger and older subjects, after correction for their VO2 peaks. Younger subjects had longer sustained exercise times (45.5±17.6 min) than the elderly (30.2±14.0 min), pre-training. Post training, there was a significant increase in VO2 peak (25%) in older subjects (P=0.001) and submaximal exercise time (30.2±14.0 vs. 58.3±27.3min, P=0.020). RESPIRATORY EXCHANGE RATIO was reduced during both exercises after training (0.90±0.03 vs. 1.00±0.03, P=0.04). Conclusions: The RER of older subjects was not different from that of younger subjects, after correction for the VO2 peak. The VO2 peak, sustained exercise time, and RER decreased after training in older subjects, indicating increased fat metabolism.

Background: Studies reported conflicting results about the relationship between anthropometric factors, RESPIRATORY EXCHANGE RATIO, energy expenditure and VO2 max. Therefore the aim of this study was to investigate the relationship between anthropometric factors, RESPIRATORY EXCHANGE RATIO and energy expenditure with VO2 max in sedentary men.Materials and Methods: Thirty one sedentary healthy men (23.67±2.45 years old age, BMI=22.49±1.58 kg/m2) volunteered for participation this study. After the measurement of anthropometric factors, subjects performed an acute endurance exercise on the ergometer for determination of VO2 max. Subjects performed major protocol, one hour cycling on ergometer via 70% VO2 max for the determination of the RESPIRATORY EXCHANGE RATIO and the rate of energy expenditure, 72 hours later.Results: The results of this study showed that there is not any significant relationship between VO2 max and anthropometric factors, RESPIRATORY EXCHANGE RATIO and energy expenditure. Also, regression analysis indicated that all these variables cannot predicate the VO2 max.Conclusion: According to the results of this study anthropometric factors, RESPIRATORY EXCHANGE RATIO and energy expenditure are not strong predictors of VO2 max in sedentary young men.

Introduction: RESPIRATORY EXCHANGE RATIO (RER) is the RATIO between produced CO2 and used O2 for body metabolism. It indicates the type of fuel that is metabolized in the body. This study aimed to measure and compare the RER in non-obese and obese sedentary young adults in rest, moderate-intensity, and vigorous-intensity exercise. Methods: This cross-sectional study was conducted with 23 non-obese and 24 obese sedentary young adults. Resting RER was measured with 12-h fasting after 15-min rest with an automated gas analyzer. Then, RER was measured during steady moderate-intensity and vigorous-intensity exercise on a cycle ergometer. RER was compared between males and females, non-obese and obese in resting, moderate-intensity, and vigorous-intensity exercise by t-test. Results: The Mean age of the non-obese and obese groups was 19. 35±, 1. 11 and 19. 79±, 0. 78 years, respectively. Males showed higher RER (in resting and moderate-intensity exercise) than females. In comparison to non-obese group, the obese group showed higher RER in resting (0. 802±, 0. 018 versus 0. 821±, 0. 022, P=0. 001), moderate-intensity exercise (0. 812±, 0. 013 versus 0. 83±, 0. 02, P<0. 001), and vigorous-intensity exercise (0. 853±, 0. 43 versus 0. 914±, 0. 032, P<0. 001). Concerning resting value, RER significantly increased during moderate-and vigorous-intensity exercise in both the non-obese and obese groups. Conclusion: Obese young adults use relatively more carbohydrates as fuel than non-obese in both resting conditions and during exercise. When the intensity of exercise increased, both obese and non-obese showed higher RER which indicates that sedentary young adults use relatively more carbohydrates as fuel in the higher grade of exercise.

Previous research has indicated that odorant presentations can have both positive and negative effects on psychological perceptions of athletic task performance. Some of the scientists found that the presence of pleasant odor in a testing room enhanced performance on cognitive and physical tasks (push-ups and 400-m run, hand grip) and led to subjects indicating more motivation and interest in the task. For many years menthol has been used for treatment of RESPIRATORY disorders although, a bronchodilator effect of menthol has yet to be described, and any .significant difference was not found in oxygen consumption. Inhaling peppermint is reported to be a stimulant for increased energy that would certainly benefit any athletic or non-athletic individual during an exercise bout.The purpose of this research was to determine the effect of peppermint odor on maximum heart rate, V02max, VO2, minute ventilation and the RESPIRATORY EXCHANGE RATIO (R). Subjects of this study were 36 female elite soccer players with mean age: 21.17±3.15 yrs, height: 160.12±6.24 cm, weight: 56.78±8.76kg and resting heart rate: 77.39±7.88 bpm. They were divided in to three groups randomly: control, inhalant peppermint essence and inhalant peppermint essence + alcohol. Kolmogorov-Smirnov Test showed that the distribution of data in groups were normal. Subjects' BMI were distinguished and ANOVA showed no significant difference in the mean of BMI of the groups (p>0.05).According to Bruce recipe the subjects did exercise on treadmill till exhaustion. Heart rate during exercise, VO2max, VO2, minute ventilation and R were measured by Gas Analyzer machine (k4b2). Statistics analysis for independent groups was by ANOVA (p>0.05). It showed that inhalation of ambient odor (peppermint essence) doesn't have any significant effects on mentioned variables (p>0.05), probably for intensity, time of exercise. So we suggest determining the effect of inhalation peppermint odor on exercise with longer time and lower intensity.

Background & Aims: Diagnostic criteria for acute lung injury (ALI) and acute RESPIRATORY distress syndrome (ARDS) requires acute onset of disease, chest radiograph demonstrating bilateral pulmonary infiltrates, lack of significant left ventricular dysfunction and pao2/fio2(PF) RATIO£300 for ALI or£200 for ARDS. And the latter one requires invasive arterial sampling. Measurement spo2 by pulse oxi metry and calculation spo2/Fio2 (SF) RATIO may be a reliable non invasive alternative to the PF RATIO.Materials & Methods: In this cross sectional study, 70 patient diagnosed for ALI or ARDS admitted in Tabriz children's hospital PICU were enrolled. Then spo2, Fio2, Pao2 charted within 5 minutes were measured and the RATIO of SF and PF were calculated and compared. SF threshold the values were determined to replacement PF RATIO for diagnose ARDS and ALI.Results: The relationship between SF and PF RATIO was described by the following regression equation SF=57+0.61PF (P<0.001). SF RATIOs of 181 and 235 corresponded of PF RATIO 300 and 200. The ALI SF cutoff of 235 had 57% sensitivity and 100% specificity, and ARDS, SF cutoff of 181 had 71% sensitivity and 82% specificity.Conclusion: SF RATIO is a reliable noninvasive marker for PF RATIO to identify children with ALI or ARDS. And can be replaced pulse oximetry by arterial blood sampling.

This study aimed to compare the effects of high intensity and high volume training on lactate accumulation, time performance and VO2peak in 10-14 years old distance runners. 20 male endurance runners aged 12.5±2.32 years old and with a height of 154.62±3.27 cm, weight of 34.5±5.12 kg, maximum heart rate of 207.5±3.1 and VO2max of 36.45±3.22 ml /kg/min took part in the experiment. The experiment was undertaken randomly in a crossover form between two modes and two groups of runners (Group A and B), and two intermittent exercise models. The exercise models included: (i) a high intensity and low volume (HT) model (60 seconds exercise with 90% VO2 peak and 60 seconds rest with 30% VO2 peak) within 30 minutes activity and (ii) a low intensity and high volume (VT) model (60 seconds exercise with 65% VO2 peak and 60 seconds rest with 30% VO2 peak) within 60 minutes activity. The experiments were performed during two 6-week periods with a 5-week rest in between. RESPIRATORY EXCHANGE RATIO (RER), Time performance in 1500 meters (T1500m) and Lactate maximum (Lacmax) were measured throughout the exercises. Repeated-measures ANOVA and Bonferroni post hoc tests were used to determine any significant difference between the groups and exercises. The results showed that there was a significant difference in the value of T1500m between pre and post HT and VT models (P<0.05).With regard to the maximum amount of RER and lactate, there was only a significant difference between pre and post HT exercise model (P<0.05). The results revealed that both HT and VT models had a significant difference in VO2peak between pre and post exercise (P<0.05). Overall, the findings of this study showed that the HT exercise model compared to the VT exercise model had higher performance on the RER, Lacmax, T1500m andVO2peak parameters. Where time limitation is an issue for athletes, the HT exercise model may therefore be a good substitution for long and boring training models.

Arterial blood gas parameters were analyzed in forty-nine healthy persons (31 males, 18 females) to determine reference values fo these parameters and their relation to the time from last food intake to arterial puncture (T). The mean ± standard deviation of arterial oxygen pressure, arterial carbon dioxide pressure and pH at core body temperature were 84.4±7.0 mmHg (Male: 83.0±6.5, Female: 86.7±73), 37.7±2.8 mmHg (Male: 38.5±2.7, Female: 36.2±2.4) respectively 7.41±0.02 (Male: 7.41±0.02 Female: 7.42±0.03). the mean PCO2 was lower in comparison with most of the studies at sea level. The difference between males and females was significant in PCO2 and PH (P=0.004, P=0.02 respectively) but in was not significant in PO2 (P=0.07). The PCO2 and pH had no statistically significant relationship with age (P=0.42, P=0.25 respectively). The relationship between Po2 with age, PCO2 and T was significant (P=0.02, P=0.017, and P=0.019 respectively). The best linear predictive equation was: Po2= 1.28 AO2-29.4 for T<10hours → AO2 =0.21 (Baro.47) –(1+0.02T) PCO2 for T >10hours Þ AO2 = 0.21(Baro-47) – (1.2PCO2