Effect Of 8 Weeks HIIT On Cardiorespiratory Fitness In Sedentary Women

Objective: One of the most important public health problems in the 21 st century is sedentary behavior,which has caused more and more people’s attention.This behavior has a negative impact on cardiorespiratory fitness.High intensity interval training(HIIT)has been rampant in recent years.In the field of sports and fitness,there is less research on the influence of cardiorespiratory fitness in sedentary people,and whether it can improve cardiorespiratory fitness and optimal exercise capacity in sedentary people.The aim of this study was to observe the changes in cardiorespiratory fitness after HIIT training in order to observe the difference before and after training by measuring cardiac and lung related indicators.Methods: 26 female college students(18-28 years old)with no less than 30 minutes a day,3 days a week of moderate intensity physical activity were randomly allocated into MCT group(n = 13)and HIIT group(n = 13).The subject undertook a graded exercise test to obtain VO2 max.Then,they carried out a 8 weeks,three sessions per week exercise training,the MCT group was trained with 60% VO2 max intensity for 30 min,HIIT group with 90% VO2 max intensity every 3min,intermittent 2min,total 6 groups were trained three times a week training for 8 weeks,according to heart rate changes in the fourth week to adjust the training program to ensure that training can give the subject to effectively stimulate.Before and after 8 weeks of training,the subjects were tested for body shape,cardiorespiratory function and aerobic exercise capacity.Use SPSS20.0 for data analysis.Results:(1)BMI,percentage of body fat(Fat%)of HIIT group and MCT group showed significant changes before and after training,but there was no significant difference between the two groups.(2)In cardiorespiratory function on the other hand,there was a significant change in VC,vital capacity index,and MVV in HIIT group.There was also a significant change in VC and vital capacity index in MCT group,and there was a significant difference between the two groups.(3)In terms of aerobic exercise capacity,maximal oxygen uptake,running economy,and exhaustion time increased significantly before and after training,and the exhaustion time were significant different between the two groups.There was no significant difference in the lactic acid clearance between the HIIT group and the MCT group;the HRR4 in the HIIT group and the MCT group had significant changes before and after training.Conclusion: Both HIIT and MCT can significantly improve lung function and aerobic performance of sedentary female,but HIIT has a better effect than MCT training.