A randomized controlled trial was conducted, recruiting 24 eligible kayakers aged 14-22 years from the Jiangxi training base, China. Participants were randomly assigned to the SUCT group and the DUCT group. Both groups completed a 12-week unstable core training program consisting of 1-hour sessions, 3 times/week. Balance ability was assessed using the flamingo balance test and star excursion balance test. Trunk muscle strength was assessed using the abdomen, back, side bridge tests, sit-up, back extension, and trunk rotation tests. Paddling performance was evaluated using the average stroke power and stroke rate for the men's K-1 200m land ergometer sprint tests.