Effect Of Short-term High-intensity Interval Training On Abdominal Fat In Obese Young Women

With the rapid development of society, living conditions of human beings are getting improed and the numbers of problem related to obesity have also been increasing. In recent years, especially, the metabolic disorders caused by obesity show an upward trend. Obesity is a chronic metabolic diseases. There are many ways of sub-classification of fat. Based on the location of fat distribution, obesity can be divided into subcutaneous fat and visceral fat. The relationship between obesity-related metabolic disorders and excessive visceral fat accumulation is complicated and important. So it is significant to study how to reduce visceral fat to improve the health of obese patients.In recent years, the effects on improving the health have make high intensity intermittent exercise become a hot research. Some researches indicate that high-strength intermittent training can improve the capacity of heart and lung, insulin sensitivity and endothelial function, and also reduce body fat, blood sugar. Compared with continuous training of moderate intensity, high intensity interval training is more likely to be accenpted by people because of short time and fast pace. Related studies have indicated that high-intensity intermittent exercise can reduce abdominal fat and visceral fat. However, many intermittent high intensity exercise programs require much time. Therefore, for some sedentary obese people, they prefer short-term high intensity interval training. But there are no many studies on the optimization of intermittent high intensity training programs. Until now, high efficient program on losing weight has still not to be found. So, the research about short-term high-intensity intermittent exercise need to be developed.Purposes: Compare and analyze the results of short-term high intensity interval training and other two training programs on abdominal subcutaneous fat, visceral fat, affect body fat and aerobic capacity in obese young women. Provide theoretical guidance and new options for exercisig and losing weight for healthy and obese peple.Methods: 58 young obese women(body fat percentage: 38.59 ± 2.6%) were randomly divided into four groups: S group, H group, M group, Group C. They need to exercise for 12 weeks. In S group, Monark 894 anaerobic power bicycle was choiced to train subjects. And short-term high-intensity intermittent exercise was used in S group. The programe concludes 20 minutes and 15s(6s:all-out sprint; 9s:intermittent) is considered to be a circle. In M, H groups, Monark 839 aerobic power bicycle was used to offer subjects with same mechanical work( in the first two weeks,subjects need to overcome 200 kj mechanical work. In the next 10 weeks, the 300 kj mechanical work need to be overcomed). In M group, exercise intensity was 60% VO2 peak and exercise was continuous; In H group, exercise intensity was 90% VO2 peak, but exercise is intermitten(exercise for 4min and stop until the RPE decreased to 13) During the exercise intervention, all subjects were required to maintain the same diet and physical activity habits before intervention. After 12 weeks exercise intervention, dual energy X-ray and CT were used to measure respectively the body fat content, abdominal subcutaneous fat and visceral fat.Results1. Except VO2 peak, all the initial parameters were not significant differences between groups(P> 0.05). VO2 peak was statistically significant difference between the three exercise groups(P = 0.64).2. Changes of abdominal subcutaneous fat and visceral fat areaVisceral fat area in S group after the exercise intervention reduced by 9.1 %(69.27±23.43cm2 VS 62.95±21.85cm2, P = 0.042). Visceral fat area in H group reduced by 13.4%(68.96±24.71cm2 VS 59.87±19.09cm2, P = 0.019). There is no value interaction between S and H groupd. change(P=0.831). In addition, there was no significant difference on visceral fat area in group M and C(69.4±26.63cm2 VS 60.21±23.52cm2, P = 0.053; 69.81 ± 21.30cm2 VS 69.43 ± 19.49cm2, P = 0.725 seperately).Abdominal subcutaneous fat area in S group after the exercise intervention reduced by 7.1%(244.89±62.27cm2 vs 227.54±51.83cm2, P=0.040). Abdominal subcutaneous fat area in H group reduced by 14.1%(248.43±61.19cm2 vs213.37±51.03cm2, P=0.005). And abdominal subcutaneous fat area in M group reduced by 12.9%(219.87±47.56cm2 vs191.58±35.50cm2, P=0.008). There were no interaction between the three groups(P = 0.797,P = 0.145, P=0.234). Additionally, the data in group C show no significantly different(302.62±91.18cm2 vs 299.72±92.72cm2, P = 0.373).3. The change of fat percentage, body fat mass and body weight in experimental groupThe fat percentage, body fat mass, weight in S group, H group, M group after the exercise intervention were significantly reduced, and there was no interaction between the three groups(S group: 38.41±2.33% VS 36.34±2.12%, P = 0.000; H group: 38.14±2.28% VS 35.62±1.98%, P = 0.000; M group : 38.00±2.13% VS 35.64±2.33%, P = 0.000. S group: 25.67±3.45 kg VS 23.68±3.33 kg, P = 0.000; H group: 25.72±3.28 kg VS 22.85±3.04 kg, P = 0.000; M group: 38.00 ±2.13 kg VS 35.64±2.33 kg, P = 0.000. S group: 66.68±6.41 kg vs 64.94±6.15 kg, P = 0.000; H group: 67.33±6.09 kg VS 64.00±5.99 kg, P = 0.000; M group: 68.52±8.00 kg VS 65.14 ±7.72 kg, P = 0.000 seperately). Fat percentage, body fat mass, body weight were no significant difference in group C after the exercise intervention(P = 0.973, P = 0.437, P = 0.462).4.The changes of VO2 peak in experimental groupAfter 12 weeks of exercise training, the data about VO2 peak levels from S, H, M group were significantly improved(S group: 30.75±3.54 ml / min / kg VS 38.50±4.79 ml / min / kg, P = 0.000; H Group: 31.49± 2.17 ml / min / kg VS 39.79 ± 4.48 ml / min / kg, P = 0.000; M group: 30.61±3.53 ml / min / kg VS 38.33±4.44 ml / min / kg, P = 0.000) and There was no interaction between the three groups. VO2 peak level after the exercise intervention in C group was not significant difference(27.62 ± 2.81 ml / min / kg VS 27.56±2.20 ml / min / kg)ConclusionsAfter 12 weeks intervention, compared with other two groups, short-term high intensity interval training(HIIT) is time-conserved and high efficient on weight loss. And HIIT can effectively reduce the amount of body fat, Fat% in obese young women. Particularlly, HIIT show a good effect on reducing abdominal fat. In addition, maximal oxygen upake levels werer increased after intervention. As a result, HIIT provide obese people with a new choice to lose weight.