fatmax

The aim of study was to effect of short-term consumption of green tea on metabolic cost and substrate oxidation during acute exercise with Fatmax intensity in healthy overweight or obese men.

Fifteen men were studied as cross-examined in one group. First, on the treadmill connected to the gas analyzer, a sports protocol was performed at a speed of 3.5 km/hour, a slope of 1%, for 3 minutes, and after a 2-minute break (first stage), the activity was performed at a speed of 4 km/hour with a slope of one percent (second stage); and then at a speed of 5 km/hour (third stage); and then at a speed of 6 km/hour (fourth stage); And finally, it was implemented at a speed of 6.5 km/hour (4 minutes). Next, the participants consumed 1000 mg/day green tea for a week and came to the laboratory for the second time. Then they consumed placebo for a week and came to the laboratory for the third time. The maximum of fat oxidation (MFO) and the intensity of activity at which MFO occurs (Fatmax) were determined.

Between fat oxidation, respiratory exchange ratio, oxygen consumption and energy expenditure in two cases of 7 days green tea consumption and placebo; there was no significant difference (p>0.05).

Short-term consumption of green tea before acute exercise at Fatmax intensity has no effect on energy expenditure, oxygen consumption and fat reduction, and its consumption period and dosage should be studied further.

Amino acid taurine can increase the utilization of fatty acids and stimulation of lipolysis through augmentation of the expression of genes related to regulation of energy metabolism. The purpose of this study was to investigate the effect of taurine supplement on lipid oxidation and substrate selection during exercise in obese women. 15 obese women (Body weight: 34.53 ± 6.33 (kg), BMI: 33.12 ± 3.23 (kg/m2)) performed a standard incremental test before and after 21 days of taurine supplementation (50 mg/kg). Blood samples were collected before and after the test and breath by breath mesurment of respiratory parameters were done throughout the test. FATmax (as the point at which fat contributes the most to the consumed energy) and Cross over point (as the point at which the predominant fuel changes from fat to carbohydrates, COP) were calculated. Heart rate, workload, and oxygen consumption corresponding to FATmax and COP were determined and compared between attempts before and after supplement consumption using independent t-test and analysis of variance with repeated measures. Following taurine consumption for 21 days, the changes in serum levels of estrogen and progesterone hormones, maximum oxygen consumption, and time to exhustion during incremental exercise test were significantly higher than before supplement consumption. Nevertjeless, the consumption of supplement had no effect on heart rate, workload and oxygen consumption corresponding to FATmax and COP points. Despite the increase in performance variables during exercise, taurine supplementation has no effect on substrate selection during exercise in obese women.

The aim of this study was to compare of maximal fat oxidation and the exercise intensity that elicit maximal fat oxidation (Fatmax) between active and inactive elderly men.

10 healthy elderly men that had regular exercise (at least 10 past years, ,VO2max 44.6±4.5 ml.kg.min) and 10 healthy elderly men that hadn’t any regular exercise (at least 10 past years, VO2max 30.9±3.2 ml.kg.min), were selected as the subjects of this study. Then, the participants performed an incremental exercise test at 8 to 10 am in the fasting state, including: activity with 3 minutes stages on treadmill to exhaustion. The amount of maximal fat oxidation and Fatmax were measured through indirect calorimetry method using the gas analysis system with aim of stoichiometric equation. To compare the variables, independent t test (p>0.05) was used.

Fat oxidation rate in range of intensities, maximal fat oxidation and Fatmax in active elderly men was significantly higher than inactive elderly men (p<0/05). but, Carbohydrate oxidation rate in range of intensities were significantly lower in the active compared to inactive elderly (p<0/05).

In general, it was found that better state of fitness in active elderly associated with more fat oxidation and less carbohydrate oxidation in range of intensities. Moreover the amount of maximal fat oxidation and Fatmax decrease in elderly, but This decrease can partly be prevented with regular exercise.