| Nowadays, the incidence of obesity and its related metabolic disease (ascoronary disease and diabetes Type II) has dramatically increased worldwide,becoming one of main health risk factors, as a result of sedentary jobs, physicallyinactive lifestyle and/or high caloric diet. Therefore, increasing exercise and dietcontrol are basic means of preventing such diseases. Moderate-intensity ContinuousTraining (MCT) has become an acceptable way of losing weight and body buildingsince it may increase fat consumption and improve glycolipid level and aerobic fitness.However, moderate-intensity aerobic training regime is an exercise of monotony andrequires a huge commitment by participants in terms of time and effort, mostpopulations, obese people in particular, generally do not adhere to the training.In recent years, the results of High-intensity Interval Training (HIT) on people’shealth have been widely followed by scholars. The effectiveness of HIT has beenpreliminarily confirmed in improving cardio-pulmonary function, insulin resistanceand vascular endothelial function and in lowing blood glucose and body fat content.For equivalent amount of exercise, HIT requires less time and adherence than MCT.The weight-reducing effects of HIT are mostly assessed by using BMI and body Fat%at home and abroad while the study on the effects of HIT on different body parts,particularly abdominal fat, is not sufficient. Moreover, contrastive study on theweight-reducing effects between HIT and MCT of equivalent exercise amount arealso wanting.Purpose: To make a comparison between the changes in body fat content, bodyfat%, local fat%, especially in abdominal visceral fat and subcutaneous fat areas inobese women resulting from a12-week HIT and MCT programs by doing equivalentmechanical work.Methods:43obese women (Fat%:8.6±3%) were stochastically divided into threegroups, i.e. HIT group, MCT group and CON group, for12-week training intervention.Participants of HIT group and MCT group undergone cycle ergometer training respectively at90%V O2maxand60%V O2max,1time/day and4day/wk (3day/wk forthe first4weeks). For HIT group,4-min exercise was performed as a bout with3-4min interval while for MCT group, continuous exercise was performed. Adjust theexercise time of both groups to keep an equivalent mechanical work (from200KJ to400KJ). Participants in those three groups maintained the same caloric intake, dietaryhabits and physical activity amount with that before training intervention. Before andafter such training intervention, dual energy X-ray was adopted to determine bodyfat%and local fat%. Computerized tomographic scanning was used to measure thearea of abdominal subcutaneous/visceral fat. Meanwhile, energy consumption, heartrate and feeling of fatigue were also monitored during the training.Results:(1) Except serum cholesterol (P=0.045), the initial level of each index in thosethree groups had no statistical significance.(2) Changes in weight, body fat%and fat mass in those three groups:For HIT group and MCT group before and after intervention, reductions wereobserved in weight (HIT:68.94±12.06kg vs64.97±10.2kg, P=0.000; MCT:68.35±9.55kg vs64.13±7.9kg, P=0.000), body fat%(HIT:38.23±2.39vs36.34±2.53,P=0.000; MCT:38.66±3.32vs37.03±2.5, P=0.004) and fat mass (HIT:26.54±6.05kgvs23.78±4.98kg, P=0.000; MCT:27.26±5.5kg vs23.79±3.71kg, P=0.003), havingstatistical significance. However, the reduction ranges for the said two groups had nostatistical significance. For CON group before and after intervention, such indexes asweight (P=0.986) and fat mass (P=0.823) had no statistical significance; but bodyfat%(P=0.027) increased, having statistical significance.(3) Changes of fat mass in different body parts in those three groupsAfter12-wk intervention, HIT group resulted in reduction of fat mass inabdominal Android area (2.07±0.63kg vs1.88±0.58kg, P=0.001), having statisticalsignificance. For MCT group and CON group, fat mass had no statistical significancein abdominal Android area (MCT:1.96±0.45kg vs1.82±0.29kg, P=0.055; CON:2.33±0.83kg vs2.3±0.86kg, P=0.683).After12-wk intervention, HIT group and MCT group resulted in reduction of fat mass in pelvic Gynoid area (HIT:4.6±0.84kg vs4.31±0.74kg, P=0.000; MCT:4.49±0.81kg vs4.27±0.62kg, P=0.038), having statistical significance, but thereduction ranges had no statistical significance. For CON group, fat mass had nostatistical significance in pelvic Gynoid area (4.99±1.39kg vs5.02±1.39kg, P=0.657).After12-wk intervention, HIT group and MCT group resulted in reduction of fatmass in left arm (HIT:1.58±0.38kg vs1.4±0.34kg, P=0.000; MCT:1.54±0.39kg vs1.42±0.29kg, P=0.022), right arm (HIT:1.54±0.42kg vs1.42±0.37kg, P=0.002;MCT:1.56±0.37kg vs1.43±0.24kg, P=0.015), trunk (HIT:12.74±3.58kg vs10.78±2.84kg, P=0.000; MCT:12.68±2.59kg vs10.72±1.86kg, P=0.001) and right leg(HIT:4.88±0.97kg vs4.63±0.82kg, P=0.002; MCT:4.94±0.99kg vs4.62±0.81kg,P=0.009), having statistical significance, but the reduction range of each indexabove-mentioned had no statistical significance. Before and after12-wk intervention,for CON group, fat mass had no statistical significance in left arm (1.63±0.55kg vs1.57±0.54kg, P=0.127), right arm (1.75±0.73kg vs1.78±0.73kg, P=0.416) and trunk(13.91±4.9kg vs13.48±4.45kg, P=0.361). Nevertheless, the fat mass in right leg(5.35±1.6kg vs5.56±1.64kg, P=0.004) resulted in an increasing, having statisticalsignificance.After12-wk intervention, HIT group resulted in reduction of fat mass in left leg(4.73±0.88kg vs4.49±0.75kg, P=0.009), having statistical significance. For MCTgroup and CON group, fat mass in left leg (MCT:4.74±1.1kg vs4.54±0.84kg,P=0.139; CON:5.23±1.57kg vs5.31±1.58kg, P=0.304) had no statistical significance.After12-wk intervention, MCT group resulted in reduction of fat mass in head(1.1±0.1vs1.06±0.09, P=0.008), having statistical significance. For HIT group andCON group, fat mass in head (HIT:1.62±2.19kg vs1.06±0.11kg, P=0.332; CON:1.07±0.09kg vs1.12±0.12kg, P=0.002) had no statistical significance.(4) Changes of abdominal visceral/subcutaneous fat areas in those three groupsBefore and after intervention, HIT group resulted in16.38%reduction in area ofabdominal subcutaneous fat (34.53±16.38cm2vs29.67±11.96cm2, P=0.007) whileMCT group had no statistical significance (P=0.843). The interaction of change valuebetween HIT group and MCT group was observed (16.38%vs0.7%, P=0.023). For CON group before and after intervention, abdominal visceral fat area had nostatistical significance (33.05±9.13cm2vs32.53±11.23cm2,P=0.691).HIT group and MCT group resulted in reduction in abdominal subcutaneous fatareas by18.3%and12.5%respectively (HIT:131.61±42.04cm2vs111.25±35.64cm2,P=0.000; MCT:132.94±31.98cm2vs118.18±20.25cm2,P=0.01), comparedwith that before intervention, having statistical significance, but the reduction rangeshad no statistical significance. For CON group, abdominal subcutaneous fat area(142.99±41.68cm2vs143.47±37.48cm2, P=0.941) had no statistical significance.(5) Changes of serum index and V O2maxin those three groupsBefore and after12-wk intervention, such indexes as glycerin trilaurate (HIT:0.84±0.38mmol· L-1vs1.01±0.44mmol· L-1; MCT:0.9±0.29mmol· L-1vs0.92±0.42mmol· L-1; CON:0.84±0.26mmol· L-1vs0.95±0.36mmol· L-1),cholesterol (HIT:3.25±0.52mmol· L-1vs3.45±0.72mmol· L-1; MCT:3.74±0.56mmol· L-1vs3.75±0.7mmol· L-1; CON:3.38±0.5mmol· L-1vs3.47±0.92mmol· L-1), low density lipoprotein (HIT:1.8±0.4mmol· L-1vs1.94±0.56mmol· L-1; MCT:2.09±0.49mmol· L-1vs2.25±0.53mmol· L-1; CON:1.85±0.36mmol· L-1vs2.01±0.71mmol· L-1) had no statistical significance (P>0.05).After12-wk intervention, MCT group resulted in reduction in high densitylipoprotein (1.24±0.2mmol· L-1vs1.08±0.18mmol· L-1, P=0.042), having statisticalsignificance. For HIT group and CON group, such index (HIT:1.07±0.25mmol· L-1vs1.05±0.23mmol· L-1, P=0.812; CON:1.15±0.27mmol· L-1vs1.03±0.23mmol· L-1, P=0.162) had no statistical significance.After12-wk intervention, HIT group and MCT group resulted in increasing inV O2max(HIT:30.18±4.4ml·kg-1·min-1vs34.34±4.55ml·kg-1·min-1, P=0.000; MCT:28.11±3.81ml·kg-1·min-1vs31.71±3.75ml·kg-1·min-1, P=0.000), having statisticalsignificance, but the increasing range had no statistical significance. CON groupresulted in reduction in V O2max(29.56±3.65ml·kg-1·min-1vs28.09±3.6ml·kg-1·min-1,P=0.02), having statistical significance.Conclusion:(1) Both12-wk HIT and MCT programs with equivalent mechanical work resulted in reductions in body fat%and fat-total in obese young women, having nodifferent results.(2)12-wk HIT resulted in reductions in abdominal while MCT with equivalentmechanical work had no statistical significance in fat reduction.(3)12-wk HIT resulted in reductions in abdominal visceral fat while MCT withequivalent mechanical work had no statistical significance in fat reduction, in thisconnection, HIT was better than MCT; both HIT and MCT resulted in reductions inabdominal subcutaneous fat.(4)12-wk HIT and MCT resulted in enhancement in V O2maxin obese youngwomen and had no different results. |
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