Effects of core training on physical performance in team-sport athletes: a systematic review and meta-analysis

Core training has been widely explored as a way to enhance trunk function and improve sport-specific performance. Although previous reviews provide some evidence for improvements in core-related functions such as trunk strength, endurance, and balance, evidence in relation to physical performance is mixed. Team sports are characterized by repeated accelerations, decelerations, changes in direction and body orientation, and sequential explosive actions, all of which place high demands on trunk stability and neuromuscular control of the limbs. Previous systematic reviews and meta-analyses have examined the effects of core or trunk training on athletic performance. However, evidence remains limited regarding direct comparisons between core training and non-core training controls in team-sport athletes. Therefore, this study conducts a systematic review and meta-analysis to examine these effects in this population.

Four databases (Web of Science Core Collection, PubMed, EBSCOhost and the Cochrane Library) were systematically searched. Randomized controlled trials and controlled trials comparing core training with non-core training controls in team-sport athletes were included. Risk of bias was assessed using RoB 2 for randomized trials and ROBINS-I for non-randomized controlled studies, and certainty of evidence was assessed using the GRADE framework, with reporting conducted in accordance with the PRISMA 2020 guidelines. Meta-analyses of balance, vertical jump, linear sprint time, and change-of-direction ability were performed using Stata 18, and effect sizes were calculated as standardized mean differences (SMDs) with 95% confidence intervals. Publication bias was assessed using funnel plots and Egger's regression test.

A total of 22 studies involving 588 team-sport athletes were included. Compared with non-core training controls, core training resulted in a moderate improvement in balance (SMD = 0.67, 95% CI 0.30 to 1.04; I² = 66.6%), along with small but statistically significant effects on vertical jump (VJ) (SMD = 0.35, 95% CI 0.07 to 0.62; I² = 0.0%), linear sprint (SMD = - 0.52, 95% CI - 0.79 to - 0.25; I² = 15.2%), and change-of-direction ability (CODA) (SMD = - 0.40, 95% CI - 0.66 to - 0.14; I² = 13.9%). For balance, effects were larger with > 2 sessions per week than with ≤ 2 sessions per week (SMD = 0.97 vs. 0.20; P for subgroup difference = 0.015), while no subgroup differences were found for age, intervention duration, or intervention structure. Funnel plots and Egger's regression tests showed no evidence of publication bias.

Some evidence suggests that, compared with non-core training controls, core training improves balance, VJ, linear sprint, and CODA in team-sport athletes, with the largest effects observed for balance. Higher training frequencies of more than two sessions per week were associated with greater balance gains. However, given the low to very low certainty of evidence and methodological limitations within the current literature, these results should be interpreted with caution, and further high-quality controlled trials are warranted.