This randomized controlled trial aimed to investigate the effects of a 12-week halotherapy intervention on respiratory muscle strength, pulmonary function, aerobic capacity, and intermittent running performance in elite female soccer players. Participants were randomly assigned to either a halotherapy group or a control group. Both groups followed the same preseason soccer training program, while the halotherapy group additionally received regular halotherapy sessions. Pre- and post-intervention assessments included spirometric measurements, respiratory muscle strength, estimated VO₂max, and Yo-Yo Intermittent Recovery Test Level 1 performance.

Aerobic capacity and respiratory efficiency are critical determinants of performance in elite soccer. Halotherapy, a non-pharmacological intervention involving inhalation of dry salt aerosol in a controlled environment, has been shown to improve pulmonary health in clinical populations; however, evidence in athletic populations remains limited.

This randomized parallel-group trial was conducted during the preseason period of the Turkish Women's First League. Twenty-eight elite female soccer players were randomly allocated to a halotherapy group or a control group. Both groups completed an identical 12-week soccer training program. In addition to training, the halotherapy group underwent 45-minute halotherapy sessions three times per week in a controlled halochamber environment.

Outcome measures included maximal inspiratory and expiratory pressures (MIP, MEP), pulmonary function parameters (FVC, FEV₁, PEF, MVV), aerobic capacity estimated via the Yo-Yo Intermittent Recovery Test Level 1, and total distance covered in the Yo-Yo test. Measurements were collected before and after the intervention period. The study aimed to determine whether halotherapy provides additive benefits to standard soccer training in elite female athletes.

Inclusion Criteria:

• Female soccer players aged 18-30 years
• Competing in the Turkish Women's First League
• Minimum of 5 years of competitive soccer experience
• Regular training ≥10 hours per week
• Free from injury at study entry
• Non-smokers
• Not using chronic medication
• Provided written informed consent

Exclusion Criteria:

• Presence of respiratory, cardiovascular, or metabolic disease
• Current musculoskeletal injury
• Smoking
• Pregnancy
• Use of medications affecting respiratory or cardiovascular function

Female soccer players aged 18-30 years Competing in the Turkish Women's First League Minimum of 5 years of competitive soccer experience

Individual participant data will not be shared because the study involves a small sample of elite athletes from a single professional team, which may increase the risk of indirect participant identification. Additionally, the informed consent obtained from participants did not include explicit permission for public sharing of individual-level data. Data are therefore available only in aggregated form to protect participant confidentiality.