article 2021 Intermittent Hypoxia Exposure Helps to Restore the Reduced Hemoglobin Concentration During Intense Exercise Training in Trained Swimmers Xiquan Weng, Jieru Lin, Yu Yuan, Baoxuan Lin, Weiwei Huang, Hiu Tung Tin, Jia Li, Xu Yan, Wentao Lin, Hao Chen JournalFrontiers in PhysiologyDOI10.3389/fphys.2021.736108Publication typeOriginal ResearchPopulationtrained swimmers View on DOI ↗