Study On The Characteristics Of Substrate Metabolism And Maximum Fat Oxidation In Increasing Load Exercises In Population Aged 20-69

Objective:To study the metabolic characteristics of substrate in the progressive exercise experiment of 20-69 years old population,and to explore the changes of fat oxidation characteristics with age,gender and BMI.The age,sex and BMI of the maximum fat oxidation intensity were studied.Characteristics and correlation with metabolic indicators;explore the correlation between maximum fat oxidation intensity and anaerobic threshold intensity.Methods:Recruited 264 people aged 20-69 in Hezhou City,Guangxi.On the day of the test,the fasting blood was collected to measure the blood index,and then the basic function indexes such as height,weight,heart rate,and blood pressure were tested.The power bicycle step-by-step incremental load exercise test was used to test the cardiopulmonary endurance of the subject,and the gas metabolism data was collected throughout,according to These data calculate substrate metabolism,including carbohydrate?CHO?and fat oxidation rates,and statistical anaerobic threshold?AT?based on gas data results.The maximum fat oxidation rate?MFO?and the corresponding exercise intensity?Fatmax?were determined according to the linear change of the fat oxidation rate throughout the whole process.For the data that meets?or approximates?the normal distribution,the parameter test is used.For the data that does not conform to the normal distribution,the non-parametric rank sum test is used.The difference between the two groups is analyzed by the independent sample T test,and the three groups and above are used.The difference analysis was performed using one-way analysis of variance,and the correlation between Fatmax and metabolic indicators and AT was analyzed using partial correlation.Results:?1?The CHO and fat supply ratio of male overweight and obese people in progressively increasing load exercise was similar to that of normal weight group at0-50W,and the fat supply ratio of 75-150W overweight obesity and normal body weight was 28%VS23%,17%VS15%,14%VS10%,11%VS11%.The fat supply of female 0-150W overweight obesity and normal weight was 22%VS20%,34%VS33%,28%VS23%,14%VS7%,6%VS3%,2%VS6%,1%VS5%.?2?The fat supply rate of the 20-44 years old population peaked at 50W?the peaks of overweight and obese men,normal weight men,overweight and obese women,and normal weight women were27.71,31.23,21.37,19.44 cal/min/kg,respectively?.Overweight and obese men aged45-59 reached the peak fat supply rate of 24.45 cal/min/kg at 75 W,the peaks of normal weight male,overweight and obese female,normal weight female appeared at 50W were 23.88,20.45,19.43 cal/min/kg,respectively,the peak fat supply rate of men and women in 60-69 years old appeared at 50W,25W,respectively.The peak values of overweight and obese men,normal weight men,overweight and obese women,and normal weight women were 16.07,21.11,13.30,17.61 cal/min/kg,respectively,fat oxidation rate decreases with age.?3?Fatmax of women aged 50-59 was significantly higher than 20-29 years old?P<0.05?and 30-39 years old?P<0.05?,and Fatmax of 60-69 years old was significantly higher than 30-39 years old?P<0.05?.?4?There was a negative correlation between female Fatmax and waist circumference?r=-0.309,P<0.01?.?5?In the male population,Fatmax,MFO and AT of overweight and obese people have a significant positive correlation,and the correlation coefficient of normal weight is higher than that of overweight and obese?0.784VS0.653,0.602VS0.320?.There was a significant positive correlation between MFO and maximal oxygen uptake(VO_2max)in normal weight?r=0.349,P<0.01?.?6?There was a significant positive correlation between female normal body weight and overweight and obesity Fatmax and AT?r=0.508,0.323,P<0.05?.Fatmax of overweight and obese and normal weight women was significantly negatively correlated with VO_2max,the correlation coefficients were-0.303?P<0.05?and-0.293?P=0.01?,respectively.Conclusions:?1?Fatmax increases when women age,and Fatmax decreases with increasing waist circumference.The higher VO_2max,the lower Fatmax.?2?Fatmax is positively correlated with AT in the 20-69 years old population.The higher Fatmax,the higher AT.