PURPOSE: The ultimate frisbee (UF) is characterized by performing throwing and receiving actions in different directions with the upper body with a pivot in the lower body while running, changes of direction, accelerations, deceleration and jumps during the frisbee moves. It demands a high muscular load on the lower body, especially the knee joint. The purpose is determine the effect of core strength training on the development of strength in the hamstrings. METHODS: Quasi-experimental study that implements 8 weeks of core training, carried out in 12 elite athletes of Colombian team. The hamstrings are evaluated through a uniaxial force platform using the isometric hamstring test. Each player was asked to perform a maximum isometric contraction for 3 seconds in the supine position with flexion of the knee and hip at 90°.Three trials were made with each leg, with 30 second rest intervals between each. Training is carried out in times of pandemic which it is done virtually. RESULTS: The differences found were not significant between the pre and subsequent performance of the core strengthening protocol with respect to the vertical peak force (192.5 N vs. 213.3 N, p = 0.082). Likewise, it was found that the variation between the right leg (182.8 N vs 207.5 N, p = 0.14) and the left leg (202.2 N vs 219.2 N, p = 0.35) had no changes significant. CONCLUSIONS: The findings show that the core training used is a good training strategy for the central region but has no influence on stability and load transfer to the lower body (Knee Stabilizers). The rehabilitation protocols focus on the hamstring, however, in traditional training, the specific preparation and strengthening of the stabilizing region of the knee is not taken into account, which is the one with the highest incidence and prevalence of injury. The training mechanisms must not only depend on a good CORE for the performance of the sport and prevention of injuries, it must focus on exercises and types of eccentric contractions which are the most common injury mechanism. Although the transfer of energy and forces through fascial tissue is carried out by muscle chains and through the muscle group that allows the body to stabilize (CORE), the joint training of all muscle chains is required without the exclusivity of a single approach.