Effects of slackline training on trunk muscle endurance, dynamic balance, and physical performance in young adults: a randomized controlled trial

This study aimed to investigate the effects of slackline training on trunk muscle endurance, dynamic balance, and physical performance parameters in young adults. Forty participants were randomly assigned to the slackline group or a control group. The slackline group completed 18 supervised slackline sessions over six weeks (three sessions per week, each lasting 45 min), while the control group maintained their usual activities. Trunk muscle endurance, dynamic balance (Y Balance test), sprint performance, and vertical jump height were assessed before and after the intervention. The effects of the intervention were analyzed using ANCOVA, with group and gender as fixed factors and baseline scores as covariates. At the 6-week assessment, baseline- and gender-adjusted between-group differences favored the slackline group for trunk muscle endurance (adjusted between-group mean difference: 27.19 s; 95% CI:20.87 to 33.51; p < 0.001; partial η²=0.679) and Y Balance Test performance (adjusted between-group mean difference: 14.92 cm; 95% CI:12.19–17.65; p < 0.001; partial η²=0.773). The slackline group also showed a lower 20-m sprint time (adjusted between-group mean difference: -0.61 s; 95% CI: -0.75 to -0.48; p < 0.001; partial η² = 0.704) and greater vertical jump height (adjusted between-group mean difference:4.06 cm; 95% CI:3.05 to 5.06; p < 0.001; partial η²=0.650). Component-level analyses of trunk muscle endurance showed between-group differences favoring the intervention group, particularly for trunk flexion and extension endurance. Six weeks of supervised slackline training produced favorable between-group differences in trunk muscle endurance, dynamic balance, 20-m sprint time, and vertical jump height, adjusted for baseline and gender, compared with usual daily activities in healthy young adults. These findings support the potential use of slackline training as an exercise modality targeting these specific functional and performance outcomes. NCT07050849. Retrospectively registered on 30/05/2025 ( https://clinicaltrials.gov/study/NCT07050849 ).