Effects of core training on physical fitness in trained adolescent athletes: a systematic review and meta-analysis

Abstract Core training is widely used to support youth athletic development, yet its effects in trained adolescent athletes remain uncertain. This systematic review and meta-analysis evaluated whether core-focused interventions improve physical fitness in athletes aged 10–19 years classified as McKay Tier 2 or above. PubMed, Web of Science, Cochrane Library, Embase, and Scopus were searched for controlled trials, including randomized and non-randomized designs. Random-effects models were used to pool standardized mean differences with Hedges’ g. Thirty-one studies involving 818 athletes were included. Compared with control conditions, core training was associated with significant improvements in countermovement jump, standing long jump, ≥ 20-m sprint, change of direction, dynamic balance, static balance, core stability, dynamic core endurance, and isometric core endurance. The evidence for ≤ 10-m sprint performance was inconclusive. The certainty of evidence ranged from moderate to very low. Overall, benefits appeared more consistent for balance and core-related outcomes than for jumping, sprinting, and change-of-direction performance. These findings suggest that core-focused exercises may serve as a supplementary component of regular training, particularly for improving postural control, core stability, and core endurance, while indicating that transfer to jumping, sprinting, and change-of-direction performance may be more limited. PROSPERO registration: CRD420261379288.