Comparing HICT and MICT for Health Improvements in Overweight Young Adults

• Participants will be recruited consecutively via online forms distributed throughout universities and networks across Jakarta and its surrounding area. Interested individuals will go through early screening. Eligible candidates will then complete an initial assessment at the research site.
• Research assistants will use standard operational procedures for each assessment. The training for research assistants will be done before data collection. One group of research assistants are responsible for main outcome data collection. The researcher is responsible for data analysis. Continuous evaluations will be done weekly to improve the research process.
• Sample size is measured from the 6-research outcomes using the sample size calculation formula for evaluating the mean difference between two variables in repeated measurements.
• Eligible candidates who passed the initial assessment will be randomly divided into HICT (intervention) and MICT (control). The 12-week exercise program in both groups will change gradually in volume, intensity, and supervision. Both volume and intensity will be increased according to heart rate targets. Supervision will decrease gradually from fully supervised in the first 4 weeks, partially supervised in the second 4 weeks, and no supervision in the third 4 weeks.
• Data will be collected and electronically recorded during each training session at the research site by the researcher and research assistants. This data includes time, heart rate, blood pressure, rating of perceived exertion (Borg Scale), training intensity, weight used, and enjoyment (PACES).
• Subjects are encouraged to report any problem during intervention via online messaging or during on-site sessions to the research assistants. The reports will be documented in a separate form. The research assistant leading the data collection will ensure that no data is missing by performing daily checking.
• Data collection for the main outcomes will be done by a different group of research assistants and will be masked from the intervention groupings.
• Data analysis will be done using SPSS 26.0 by the researcher. The analysis will be started after baseline measurements are completed. We will present all normally distributed numeric data as mean and standard deviations and non-normally distributed numeric data as median and minimum-maximum range. Bivariate analysis of normally distributed data will be done using repeated 2-way ANOVA test or mixed linear model in case of many dropouts. If data is not distributed normally, the Friedman test will be used. Any missing data will be stated and completed immediately. Close supervision for each subject will be done by research assistance to ensure all necessary reports are collected and analysed.

Inclusion criteria

• Overweight (BMI 23-24.9 kg/m2)
• Physically inactive in the last 6 months before the study (<150 minutes of moderate-intensity activity and <75 minutes of high-intensity activity)
• Willing to participate in exercise program for 12 weeks
• No other exercise program during the study period

Exclusion criteria

• Smoking
• Medical comorbidities (diabetes mellitus, hypertension, cardiovascular disease, asthma, dyslipidaemia, epilepsy)
• History of musculoskeletal injuries or health problems related to exercise in the last 1 year

Dropout Criteria

• Resigning
• Not participating in the endline assessment
• Not participating in the exercise program for 2 consecutive weeks
• Experiencing injury or health problems that led to the inability to participate in the program for 2 consecutive weeks