Effects of high-intensity interval training on improving arterial stiffness in Chinese female university students with normal weight obese: a pilot randomized controlled trial

Fig. 1. Flow chart diagram. The recruiting and screening process of normal weight obesity (NWO) female university students for study protocol. The assessment indicators include the body composition, lipid profile, and cardiovascular function

Fig. 2. HIIT intervention protocol. HIIT was performed with 9 min of high-intensity exercise combined motion (40 s for each movement interspersed with 20 s for interval rest) followed by 1 min of recovery rest and this was repeated 3 bouts and ended with 10 min static stretching, five times a week. After 4-week, the body composition, lipid profile, and cardiovascular function were detected to observe the effects of HIIT

Fig. 3. Effects of HIIT on heart rate and blood pressure. Changes of A HR (heart rate), B SBP (systolic blood pressure), and C DBP (diastolic blood pressure) were examined pre- and post-experiment using PASESA AVE-2000 PLUS. n = 13 Control group, n = 17 HIIT group. Repeated measures ANOVA followed by simple effect test analysis were used. Data are presented as mean ± SE. *p < 0.05, **p < 0.01, HIIT group (post) vs. Control group (post); #p < 0.05, ##p < 0.01, pre vs. post in HIIT group; △p < 0.05, △△p < 0.01, pre vs. post in Control group

Fig. 4. Effects of HIIT on blood lipids. Changes of A TC (total cholesterol), B TG (Triglyceride), C LDL (Low-density lipoprotein), D HDL (High-density lipoprotein), and E TC/HDL (Total cholesterol/High-density lipoprotein) were examined pre- and post-experiment using Cholesterol Monitoring system CCM-111. n = 13 Control group, n = 17 HIIT group. Repeated measures ANOVA followed by simple effect test analysis were used. Data are presented as mean ± SE. *p < 0.05, **p < 0.01, HIIT group (post) vs. Control group (post); ##p < 0.01, pre vs. post in HIIT group; △p < 0.05, pre vs. post in Control group

Fig. 5. Effects of HIIT on AVI and API. Changes of A AVI (arterial velocity pulse index) and B API (arterial pressure volume index) were examined pre- and post-experiment using PASESA AVE-2000 PLUS. n = 13 Control group, n = 17 HIIT group. Repeated measures ANOVA followed by simple effect test analysis were used. Data are presented as mean ± SE. *p < 0.05, **p < 0.01, HIIT group (post) vs. Control group (post); ##p < 0.01, pre vs. post in HIIT group; △p < 0.05, pre vs. post in Control group