The background of this study is the importance of core strength in supporting body stability and movement control. Members of an aerobic gymnastics community who regularly engage in physical activity do not necessarily possess optimal core muscle strength, as aerobic exercise does not specifically focus on strengthening the core muscles. Pilates Mat and Pilates Reformer are training methods that can be used to strengthen the core muscles, but they have different training characteristics. This study addresses the effects of Pilates Mat and Pilates Reformer training on core strength, the differences between the effects of these two methods, and which method produces greater improvements among members of an aerobic gymnastics community in Magelang. The purpose of this study was to determine the effects and differences between the two training methods and to compare their improvements in core strength. This study employed a quantitative approach with a quasi-experimental design using a Two-Group Pretest–Posttest Design. The sample consisted of 20 members of the Maple Magelang aerobic gymnastics community, with 10 participants in each group assigned through ordinal pairing. The intervention was conducted over 14 sessions. Data were measured using a Back and Leg Dynamometer and analyzed using Mixed Analysis of Variance (Mixed ANOVA). The results showed that the mean core strength of the Pilates Mat group increased from 46.00 to 88.05, representing a mean change of 42.05. In the Pilates Reformer group, the mean increased from 44.85 to 67.15, representing a change of 22.30. The Mixed ANOVA results indicated a significant change over measurement time (F = 85.091; p < 0.001) and a significant interaction between measurement time and training group (F = 8.015; p = 0.011). These findings indicate that changes in core strength differed significantly between the two groups. The analysis of the group effect also revealed a statistically significant result (F = 4.667; p = 0.044).