Effects Of Different High-intensity Interval Training Programs On Abdominal Visceral Fat In Obese Young Women

Abdominal obesity,especially excessive visceral fat,is a negative health risk factor to modern human beings.Exercise training is a basic strategy for the improvement of body fat,and exercise intensity is a critical element in reducing abdominal visceral fat.Although moderate-low intensity endurance exercise with high volume has been confirmed to be effective for the abdominal visceral fat reduction,the prolonged aerobic-type exercise requires a huge commitment by participants in terms of time and effort,making it less practical for development into strategy for controlling obesity.An important factor that restricts modern people's adherence exercising is lack of time.Therefore,it is necessary to find short-term,easy to adhere and effective ways to lose weight.In recent years,a growing body of literature showed that high-intensity interval training?HIIT?regimes could induce similar favourable metabolic adaptations and obesity control associated with moderate-intensity continuous training?MICT?,and it appears to be more effective than MICT for controlling abdominal visceral fat with equal exercise energy expenditure or work of interventions.However,most studies currently use the minimum exercise intensity of HIIT,and the volume of exercise is still relatively high.whether to enhance the intensity of HIIT?while more shorten the exercise time?,and reducing the volume of exercise reduce is still valid needs further study.Objective:This study was to compare the changes in body fat content,especially abdominal visceral fat in obese young females resulting from a 12-week MICT and three different intensity levels of the HIIT programs.Methods:75 participants were randomly assigned to one of five groups:SIT?n=15?,HIIT₁₂₀?n=15?,HIIT₉₀?n=15?,MICT?n=15?,or CON?n=15?.The SIT,HIIT₁₂₀,HIIT₉₀0 and MICT all completed the exercise intervention of 12 weeks?44times?,and the CON group did not training.The SIT group consisted of repeated cycles of sprinting for 6 s followed by a 9 s passive recovery until the 40 sets?4min of exercise time?is achieved.HIIT₁₂₀ group consisted of repeated 1-min cycling exercise bouts with intensity set at 120 _2max,followed by a 1.5-min passive recovery until the targeted 200 kJ of work is achieved.HIIT₉₀ group consisted of repeated 4-min cycling exercise bouts at an intensity of 0 _2max,followed by a passive recovery?RPE decreasd to 13?until the targeted 200 kJ of work is achieved.MICT group exercised at 60 _2max until the targeted 200 kJ of work is achieved.The abdominal visceral fat area?AVFA?and abdominal subcutaneous fat area?ASFA?of the participants were measured through computed tomography scans preintervention and postintervention.Total fat mass and the fat mass of the android,gynoid,and trunk regions were assessed through dual-energy X-ray absorptiometry.Dietary energy intake and habitual energy expenditure were not altered during the intervention.Results:After the intervention,a significant reduction in whole body fat mass and the fat mass of the trunk regions was observed in both intervention groups?p<0.05?;the reduction in the three high intensity groups was significantly greater than MICT?p<0.05?.A significant reduction in the fat mass of the android regions was observed in both intervention groups?p<0.05?;the reduction in the HIIT₉₀ groups was significantly greater than MICT?p<0.05?.A significant reduction in the fat mass of the gynoid regions was observed in both HIIT groups?p<0.05?;MICT did not change significantly?p>0.05?.A significant reduction in AVFA was observed in both HIIT groups,?p<0.05?;MICT did not change significantly?p>0.05?.A significant reduction in ASFA was observed in the SIT and MICT?p<0.05?;HIIT₁₂₀ and HIIT₉₀ did not change significantly?p>0.05?.None of the variables in the CON group differed significantly post-intervention?p>0.05?.Conclusions:1.At a lower volume of exercise,HIIT and MICT regimes successfully produced significant reductions in the fat mass of the whole-body in obese young females,and HIIT had a greater effect than MICT.2.At a lower volume of exercise,HIIT regimes can significant reductions in the AVFA in obese young females.But MICT did not.3.Sprint interval training can still reduce AVFA in young obese women.