Background: Breath-hold training (BHT) has emerged as a novel strategy to enhance metabolic efficiency and autonomic resilience in national-level athletes. This signalgenerating single-case study examined physiological and neuroendocrine adaptations to an eight-week BHT program in a nationally ranked competitive swimmer. Methods: A national-level 23-year-old female freestyle sprinter (50 m best time = 26.59 s; 100 m = 60.40 s) completed three weekly BHT sessions integrated into her regular training. Pre- and postintervention assessments included an incremental Mader cycling test with measurements of blood lactate ([La−]), heart rate (HR), salivary cortisol (sCort), and salivary alpha-amylase (sAA). Blood chemistry and pulmonary function, including diffusing capacity of the lung AcademicEditor: Giuseppe Musumeci Received: 20April2026 Revised: 9May2026 Accepted: 25May2026 Published: 28 May2026 Copyright: ©2026bytheauthors. Licensee MDPI,Basel,Switzerland. This article is an open access article distributed under the termsand conditions of the Creative Commons Attribution (CC BY)license. for carbon monoxide (DLCO), were also evaluated. Results: Post intervention, the athlete demonstrated reduced [La−] and HR at all workloads, a 20 W increase in power at 4 mmol·L−1 [La−], and an elevated final workload achieved during the Mader test. Salivary stress biomarkers showed blunted responses with significant reductions in area under the curve and large effect sizes. These changes were observed under standardized preanalytical conditions and individualized training adjustments. Conclusions: This study highlights coordinated improvements in metabolic, cardiovascular, and stress regulation mechanisms following BHT in a swimmer with verified national-level performance benchmarks. BHT, when applied in sport-specific contexts, may serve as an effective adjunct to high-performance training.
Metabolic, Cardiovascular, and Stress Biomarker Adaptations to Breath-Hold Training in a National-Level Swimmer: ASignal-Generating Single-Case Study
Gabriella D'Orsi
;Paride Vasco;Giulia Scioscia;Giuseppe Cartagena;Luigi Antonio Marinaccio;Giuseppe Cibelli;Anna Antonia Valenzano
2026-01-01
Abstract
Background: Breath-hold training (BHT) has emerged as a novel strategy to enhance metabolic efficiency and autonomic resilience in national-level athletes. This signalgenerating single-case study examined physiological and neuroendocrine adaptations to an eight-week BHT program in a nationally ranked competitive swimmer. Methods: A national-level 23-year-old female freestyle sprinter (50 m best time = 26.59 s; 100 m = 60.40 s) completed three weekly BHT sessions integrated into her regular training. Pre- and postintervention assessments included an incremental Mader cycling test with measurements of blood lactate ([La−]), heart rate (HR), salivary cortisol (sCort), and salivary alpha-amylase (sAA). Blood chemistry and pulmonary function, including diffusing capacity of the lung AcademicEditor: Giuseppe Musumeci Received: 20April2026 Revised: 9May2026 Accepted: 25May2026 Published: 28 May2026 Copyright: ©2026bytheauthors. Licensee MDPI,Basel,Switzerland. This article is an open access article distributed under the termsand conditions of the Creative Commons Attribution (CC BY)license. for carbon monoxide (DLCO), were also evaluated. Results: Post intervention, the athlete demonstrated reduced [La−] and HR at all workloads, a 20 W increase in power at 4 mmol·L−1 [La−], and an elevated final workload achieved during the Mader test. Salivary stress biomarkers showed blunted responses with significant reductions in area under the curve and large effect sizes. These changes were observed under standardized preanalytical conditions and individualized training adjustments. Conclusions: This study highlights coordinated improvements in metabolic, cardiovascular, and stress regulation mechanisms following BHT in a swimmer with verified national-level performance benchmarks. BHT, when applied in sport-specific contexts, may serve as an effective adjunct to high-performance training.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
