## 2 Methods
### Study Measures and Methods  
(1) Body composition test  
To measure body composition, the participants fasted for 2 h before the test. Height was measured using an automatic height scale (DS-103M, Dong Sahn Jenix Co., Seoul, Korea), and after removing all metal accessories on the body, weight (kg), body fat (kg), skeletal muscle mass (kg), BMI (kg/m\({}^{2}\)), visceral fat level, and percent body fat (%) were measured using a body composition analyzer (In-Body 770, Biospace Co., Seoul, Korea).  
(2) Abdominal obesity  
To test for abdominal obesity, abdominal subcutaneous fat thickness and abdominal and hip circumference were measured. Subcutaneous fat thickness was measured using a skinfold caliper (Harpenden HSK-BI, Skinfold Caliper, British Indicators, UK). With the participant standing upright with both arms comfortably rested on the side, the examiner pulled the skin 3 cm lateral to the naval to measure the thickness (mm) of subcutaneous fat. Abdominal and hip circumference were measured twice using a tape ruler around the widest part around the naval and buttocks, and the average value was used.  
(3) Blood test  
The participants fasted from 9 p.m. the day before until 10 a.m. on the day of the blood glucose and lipid test. At 10 a.m., 5 mL of blood sample was taken from the brachial vein. After 30 min of incubation at room temperature, the blood sample was centrifuged (3000 rpm, 10 min) to separate the serum layer and was immediately taken to Green Cross Laboratories, Inc. for insulin, Total Cholesterol (TC), Triglyceride (TG), low-density lipoprotein cholesterol (LDL), High-density lipoprotein cholesterol (HDL) analysis.  
(4) Muscle strength test  
Muscle strength was measured using an isometric dynamometer (TKK-5401, Takei, Japan). The participants stood with their two feet shoulder-width apart with both arms naturally rested on the sides, held the digital dynamometer with four fingers (excluding the thumb) perpendicular to the handle, and squeezed it as hard as they could. Grip strength was measured twice for each hand, and the best record was used for analysis.  
(5) Stress Index test  
Stress Index was measured using the Korean version of the Perceived Stress Scale (PSS) modified by [PERSON] (2016) based on the original scale developed by [PERSON] (1988) [28; 29]. This 10-item tool asks about perceived stress in the past months using a 5-point scale (0 = never, 1 = rarely, 2 = sometimes, 3 = frequently, 4 = very often). Negatively worded  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Nodes** & **Contents** & **Time (min)** & **Set and Rest** & **RPE** \\ \hline
**Warm-up** & Breathing, Static Stretching & 5 & & 12 \\ \hline
**HIIT exercise** & & & & \\  & Level 1: 1-2 week & & & \\  & Squat, Back lumge, Kneeing push-up tap, & & & \\  & Side steps, Crunch, Spine twist, Burpree test & & 85–90\% HRmax & \\  & Level 2: 3–4 week & & 20 s, 70\% HRmax & \\
**Main Exercise** & & & & 30 s X 10 & 15–17 \\  & Lung side kick, Down dog and push up, & & & \\  & Squat Jump, Legs raise, Plank & & & Total 2 set & \\  & Level 3: 5–8 week & & & \\  & Wall squat, Lung-twist, Knee up runs, & & & \\  & Push-up, 100 Breathing, Burpree jump & & & \\ \hline
**MICT exercise** & & & & \\  & Cycle cytometer & & & \\ \hline
**Cool-down** & Deep breathing, Total body stretching & 5 & & 12 \\ \hline \hline \end{tabular} Note: HIIT: high intensity interval training, MICT: moderate intensity continuous training.  
\end{table}
Table 2: High-intensity interval training and moderate intensity continuous training programs.  
items 4, 5, 7, and 8 were reverse scored, and the total possible score is 40, where a higher score indicates more severe stress. The reliability (Cronbach's \(\alpha\)) of the PSS used in this study was 0.83, and it was processed using SPSS 22.0 software.