Background: Background: The direction of coaching is emphasized as a factor affecting the physical conditions of pencak silat martial arts athletes in all categories. One of the physical exercises that affects body composition is aerobic activity. Objective: This study aimed to examine the effects of aerobic interval (AI) training performed for five weeks on the body mass index (BMI), basal heart rate, and the VO2max of elite athletes. Methods: The study used an experimental design involving total sampling. Thirty national-level pencak silat elite athletes (17 men and 13 women) were involved in this study. Of the participants, 23 had a normal BMI of 18.5 – 24.9 kg/m2, and 7 had a BMI above 25 kg/m2 (overweight). Their average age was 23.67 + 4.10 years with an average height of 166.03 + 7.15) cm and average initial weight of 64.84 + 12.65 kg. They were in the preparation phase of their training. This experimental research used a one-group pre-test and post-test design. The Mi Xiaomi Body Scale 2 was used for bioimpedance analysis (BIA), and body composition (body weight, BMI, body fat percentage, bone mass, protein percentage, total water body percentage, visceral fat, body age, muscle mass, and basal metabolic rate [BMR]) and VO2max measurements were acquired using a multistage fitness test (MFT). The athletes lived in a dormitory where the food, type of training and exercise, and sleeping time were controlled to the exact condition. The AI training lasted 67–77 minutes per session, twice a week for five weeks, with vigorous intensity at 80–85% of the maximal heart rate, 5 minutes per interval, and 1 minute of rest between each interval. Results: The weight, BMI, body fat percentage, basal heart rate, and VO2max showed significant differences (p 0.05) after five weeks of AI training. However, AI training did not significantly alter muscle mass, percentage of water, percentage of protein, bone mineral density, or biological age. Conclusion: AI training performed for five weeks improved VO2max and decreased basal heart rate, body weight, and fat percentage.