Karate is a martial art that originated in Japan It is characterized by its diverse techniques, including punches, kicks, strikes, and open hand techniques. Generally, karate practitioners shall execute techniques fast, with an impactful finishing towards the target. The present study aims to examine the effectiveness of customized gym sessions in enhancing the athletes’ general performance with a duration of 3-months’time. A total of 7 tests were monitored, i.e., anthropometric measurement, sit and reach test, stork balance stand test, T-test, counter movement jump, 20m sprint, and Yo-Yo endurance test. 4 male amateur athletes (state representative) that has practiced karate for at least 6 years, with at least 5 days training per week, were selected. The age ranges from 15 to 20 years old. The athletes were requested to have a proper rest (at least 7 hours sleeping time) five days before the actual test day. The results show that all athletes have at least maintained or improved stork balance for both legs. The balance improvement ranges from 0% up to 134.69%. However, both the T-test and 20m sprint test demonstrated a negative outcome. The time consumed to complete 20m is increased, which deteriorated the linear speed capability by 1.89% up to 8.93%. Also, 3 out of 4 athletes show that the T-test performance does not provide a satisfactory achievement. The agility of athletes was found to drop by 3.58% up to 10.60%. Interestingly, the athletes’ stamina was found to improve based on the VO2 max prediction and Yo-Yo test. The enhancement of VO2 max prediction and Yo-Yo test recorded as 0% - 7.53% and 9.09% - 20%, respectively. So far, there is no clear indicator on the flexibility of the athletes’ spine and length of the hamstring muscles, based on the sit and reach test. Short-term gym sessions with a duration of 3 months might improve the strength and body balance of athletes. However, the impact on the responsiveness and agility of athletes did not show any significant breakthrough. In future study, it is recommended that a large sample of participants should be included in the analysis.