Effects Of Continuous/Intermittent High Intensity Interval Training With Different Volume Of Exercise On Weight Loss In Young Obese Women

Objective:Obesity is an important factor affecting public health,and it is imperative to prevent and control obesity,and exercise is one of the basic measures to control obesity.Studies have confirmed that High Intensity Interval Training（HIIT）has a good effect on weight loss,but most HIIT programs have a high-volume,relatively long single exercise time,and continuous training,which is difficult for obese people to adhere to.In this paper,we investigate the effect of low-volume intermittent HIIT on weight loss in young obese women and compare it with high-volume continuous HIIT.Methods:Seventy-five subjects were randomly divided into five groups:the high-volume continuous HIIT group,the high-volume intermittent HIIT group,the low-volume continuous HIIT group,the low-volume intermittent HIIT group,and the no-exercise control（CON）group,with 15 subjects in each group.The high-volume HIIT group overcames 200 kilojoules（KJ）of mechanical work per exercise and the low-volume HIIT group overcame 100 KJ of mechanical work per exercise;the continuous group exercised continuously for 8 weeks,and the intermittent group exercised for 2 weeks with a 1-week interruption until completion of the 8-week exercise intervention.The exercise protocols were all exercised at 90% VO_2maxintensity for 4 minutes with a 3-minute interval and repeated until 200 KJ or 100 KJ mechanical work was completed,4 times/week.The height,weight,body mass index（BMI）,total body fat mass,body fat percentage（Fat%）,abdominal visceral fat mass,and abdominal subcutaneous fat mass were tested subjects before and after the intervention.Energy expenditure,sugar and fat oxidation were tested during the 1st,17th and 32nd exercise training sessions and during the half-hour sedentary recovery period after training.Results:（1）Body weight,BMI,total fat mass and Fat%were lower in all four exercise groups after the intervention than before the intervention（p<0.01）,while there was no statistical difference in the control group before and after the intervention（p>0.05）.The volume of exercise and whether training was interrupted did not affect the effect of HIIT on reducing body weight and BMI（p>0.05）;the effect of high-volume HIIT on reducing total fat mass and Fat%was better than that of low-volume（p<0.05）,while whether training was interrupted did not affect the effect of HIIT on reducing total fat mass and Fat%for both exercise levels（p>0.05）.（2）Abdominal visceral fat mass and abdominal subcutaneous fat mass were lower in all four exercise groups after the intervention than before the intervention（p<0.01）,whereas there was no statistical difference in the control group before and after the intervention（p>0.05）.The effect of high-volume HIIT in reducing abdominal visceral fat mass and abdominal subcutaneous fat mass was better than that of low-volume HIIT（p<0.05）,while whether training was interrupted or not did not affect the effect of HIIT in reducing abdominal visceral fat mass and abdominal subcutaneous fat mass in both exercise levels（p>0.05）.（3）Energy expenditure and glycolipid oxidation were significantly higher in high-volume HIIT than in low-volume HIIT during the exercise period and the overall"exercise+recovery"phase（p<0.01）,but there was no difference in energy expenditure and glycolipid oxidation during the recovery period between exercise HIITs（p>0.05）.Conclusion:1.The effect of low-volume HIIT on weight and BMI reduction in young obese women was the same as that of high-volume HIIT,with no effect of training interruptions on their weight loss.2.Low-volume HIIT was able to reduce Fat%,total fat mass,abdominal visceral fat mass and abdominal subcutaneous fat mass in young obese women,but the effect was lower than that of high-volume HIIT,and whether the training was interruptions or not had no effect on its effect.