Effect Of High-Intensity Interval Training On Cardiac Fitness Improvement Of Adults With Overweight/Obesity From Tanzania

ObjectivesObesity is a global and multifaceted pandemic associated with the advent of several comorbidities that are risk factors for malignant cardiac remodeling and disease.In Tanzania,the number of adults who suffered from obese or overweight had increased and caused mortality death.However,there is a lack of effective treatment strategies for obesity management because of the complexity of pathologic process in obesity.Due to its beneficial effects on cardiac health in obese or overweight subjects,high-intensity interval training（HIIT）has gained significant interest.In this study,we applied anthropometric,biochemical analysis,a 6-minutes walking test（6MWT）,and electrocardiogram（ECG）to evaluate the effect of HIIT program on the improvement of cardiac fitness（CF）in adults with overweight/obesity from Tanzania.The primary aim of this work is to provide a research basis for the treatment and rehabilitation of cardiac diseases induced by overweight or obesity in adults.MethodsSeventy-six adults（23-71 years,WHR?0.8 or BMI?25kg/m²,52.6%females）were recruited from Ligula-Mtwara and Tumbi-Kibaha Tanzania regional hospitals and randomized into an eight-week intervention as follows:（1）HIIT group[n=26,supervised HIIT program consisted of 5-6 1min bouts at80%-90%maximum heart rate（HRmax）,interspersed with 1min of active recovery at 60%-70%HRmax,4times/week];（2）Diet control group[n=25,nutrition advice was mainly performed in evening meal through diet plan,4 times/week];（3）HIIT plus Diet control group[n=25,HIIT and nutrition advice together].At baseline and after program completion,this study evaluated the interventional effects of intra-and inter-group comparisons through（1）Anthropometric,including weight,body mass index（BMI）,waist circumference（WC）,hips circumference（HC）,and WC/HC ratio.（2）Biochemical analysis,including high-density lipoprotein（HDL）,low-density lipoprotein（LDL）,Cholesterol,triglyceride（TG）,and fasting blood glucose（FBG）.（3）Cardiac fitness,including a 6-minute walking test（6MWT）,heart rate（HR）,blood pressure（BP）,blood oxygen saturation（Sp O₂）,and Electrocardiogram（ECG）.Results（1）Anthropometrics:HIIT,diet control,and HIIT plus diet control all significantly decreased the weight,BMI,WC（P<0.01,P<0.01,P<0.01）of participants,respectively.There is no difference between the three interventions.HIIT and Diet methods downregulated HC（P<0.01,P<0.01）and WC/HC ratio（P<0.05,P<0.05）,respectively.（2）Lipid profile of blood sample:HIIT,Diet control,and HIIT plus Diet control significantly decreased the FBG,LDL,and TG（P<0.01,P<0.01,P<0.01）of participants,respectively.HIIT and Diet control group displayed evident downregulation in cholesterol content of participants（P<0.01,P<0.01）,respectively.Diet and HIIT plus Diet control group significantly decreased the HDL concentration of subjects（P<0.01,P<0.01）,respectively.There is no significant difference between three interventions in lipid profile improvement of blood sample in participants.（3）Cardiac fitness:HIIT improved the walking distance of 6MWT in participants from 259.73±63.45m to 386.85±65.23m（P<0.01）,HIIT plus diet increased the data from 257±58.87m to 380.92±83.17m（P<0.01）.Compared to diet control,HIIT showed significant differences（P<0.05）.For ECG results,HIIT could significantly decreased the ST segment elevation from 53.8%to 7.7%（P<0.001）,which represents the decrease in the incidence of myocardium infarction in participants.HIIT also obviously decreased the rate of obesity-induced cardiac hypertrophy from 15.4%to 0%in subjects（P<0.001）.Conclusion（1）Eight weeks of HIIT and diet interventions showed positive improvement in anthropometrics of adults with overweight/obesity from Tanzania.（2）Eight weeks of HIIT and diet interventions decreased the high lipid profile of adults with overweight/obesity from Tanzania.（3）Eight weeks of HIIT displayed significant improvement in myocardial infection,cardiac hypertrophy,and cardiac fitness（6MWT）of adults with overweight/obesity from Tanzania.It suggested that HIIT might be the more effective method for improving cardiac function of adults who suffered from overweight/obesity in Tanzania.