SYSTEMATIC REVIEW article
Front. Physiol.
Sec. Exercise Physiology
This article is part of the Research TopicPhysiological and Pathological Responses to Hypoxia and High Altitude, Volume IVView all 4 articles
The Effect of Hypoxic Interventions on Swimming Performance in Competitive Athletes: A Systematic Review and Meta-Analysis
Provisionally accepted
- 1Inha University, Michuhol-gu, Republic of Korea
- 2Daegu University, Gyeongsan-si, Republic of Korea
- 3Jeonbuk National University, Jeonju-si, Republic of Korea
- 4Guangxi Science and Technology Normal University, Laibin, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Objectives: To evaluate the effects of hypoxic interventions (HI) on swimming performance and physiological outcomes in competitive swimmers. Design: Systematic review and meta-analysis following PRISMA guidelines and registered in PROSPERO (CRD420251170303). Methods: Seven databases were searched to identify controlled trials comparing hypoxic and normoxic training under identical conditions. Eleven studies (n = 182 swimmers) were included. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated using a random-effects model. Subgroup analyses were performed by event distance and simulated altitude. Results: HI produced a small but significant improvement in swimming performance (SMD = −0.34, 95% CI [−0.62, −0.06], p = 0.02) with low heterogeneity (I² = 30%). No significant changes were observed for VO₂max, HRmax, or VEmax (all p > 0.05). Subgroup analyses indicated greater benefits for 100 m and 200 m freestyle and for interventions conducted at simulated altitudes ≥3500 m. Conclusion: Hypoxic interventions yield meaningful yet modest enhancements in competitive swimming performance, likely through non-hematological adaptations such as improved muscle oxygen utilization and fatigue tolerance. Tailoring HI protocols to event-specific demands and sufficient hypoxic stimulus levels may optimize outcomes.
Keywords: Competitive athletes, hypoxic interventions, physiological outcomes, Simulated altitude, swimming performance
Received: 27 Nov 2025; Accepted: 27 Jan 2026.
Copyright: © 2026 Chen, Xing, Gong and Song. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Ditao Song
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.