Abstract
The High-Intensity Interval Training program quickly became one of the most popular exercise regiments due to its ability to improve health by significantly impacting the body. This experimental study focused on determining the effectiveness of a 1-month High-Intensity Interval Training program to 10 selected clients which are classified as overweight and obese. Based on the findings, it was found that after participating in High-Intensity Interval Training for one month, most of the participants successfully reduced body measurements, vital signs, and body mass index. In terms of girth measurements, participants’ abdomen, chest and waist circumference improved significantly; while forearm and the legs have a slight significant difference. Based on blood pressure, it was observed that High-Intensity Interval Training may positively help to keep blood pressure in the normal range. However, no evidence to imply that this particular program can regulate it. Lastly, based on the pre- and post-test scores of the clients, it was observed that High-Intensity Interval Training program has a significant effect on the improvement on their girth measurement, vital signs, and body mass index. Performing a similar study to support or repudiate the claims of this study is highly recommended.

Keywords
Body mass index, fitness, girth measurement, high-intensity interval training, vital sign