Work

The effect of an 8-week Life Kinetics exercise program on salivary cortisol, alpha-amylase, and ımmunoglobulin-A in U14 female cross-country skiers

Year: 2026

Type: article

Abstract: Introduction The aim of this study is to investigate the effects of an 8-week Life Kinetics exercise program on salivary biomarkers (α-amylase, cortisol, and immunoglobulin-A) in U14 female cross-country skiers. Methods A total of 20 female cross-country skiers volunteered to participate in this study. The study was designed as a pre-/post-test controlled experimental study, and adolescent individuals were randomly assigned to either the cross-country skiing (control; n = 10) or cross-country skiing + Life Kinetics groups (experimental; n = 10). The control group participated in cross-country skiing training for 45 min, 3 days a week, for 8 weeks. The experimental group participated in Life Kinetics exercises in addition to the control group’s exercises. Pre-test and post-test saliva measurements were taken before and after the 8-week protocols. Results No significant group, time, or group × time interaction effects were observed for salivary cortisol levels ( p > 0.05). For α-amylase, a significant group effect was detected ( p = 0.003), whereas neither the time effect nor the group × time interaction reached statistical significance ( p > 0.05). For sIgA, the group × time interaction was significant ( p = 0.003), while the main effects of group and time were not significant ( p > 0.05). The experimental group demonstrated an increase in sIgA levels from pre- to post-intervention, whereas the sIgA levels decreased in the control group. Conclusion The present findings indicate that the 8-week Life Kinetics intervention did not produce significant changes in salivary cortisol levels, suggesting no evidence of altered chronic stress regulation in adolescent female skiers. Although a significant group × time interaction was observed for sIgA, the overall findings should be interpreted cautiously. Taken together, the results suggest that Life Kinetics training was well tolerated from a physiological stress perspective, while further studies with larger sample sizes, longer intervention periods, and repeated biomarker assessments are needed to better clarify its effects on stress- and immune-related responses.

Source: Frontiers in Physiology

DOI: 10.3389/fphys.2026.1847163