{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T21:30:06Z","timestamp":1775856606859,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,4,30]],"date-time":"2022-04-30T00:00:00Z","timestamp":1651276800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>Background: The use of normobaric hypoxia can bring benefits to sports performance because it improves haematological parameters and\/or physical activity tests. Our objective was to conduct a systematic review so as to analyse the methods used in hypoxia and to detect its effects on middle- and\/or long-distance runners. Methods: Research was conducted using five electronic databases (PubMed, SportDiscus, Cochrane Library, Scopus and PEDro) until December 2021. The methodological quality of the included studies was assessed using the PEDro scale. Results: Having analysed 158 studies, 12 were chosen for the qualitative and quantitative synthesis. A significant improvement on time until exhaustion was detected, and oxygen saturation decreased after the intervention. There were no significant changes in the 3000-metre time trial or in the haematocrit percentage. The changes in percentage of reticulocytes, heart rate, maximal heart rate, lactate concentration and erythropoietin were heterogeneous between the different research studies. Conclusion: short exposure (less than 3 h to normobaric hypoxia significantly increases the time to exhaustion). However, longer exposure times are necessary to increase haemoglobin. Altitude and exposure time are highly heterogeneous in the included studies.<\/jats:p>","DOI":"10.3390\/biology11050689","type":"journal-article","created":{"date-parts":[[2022,4,30]],"date-time":"2022-04-30T05:44:07Z","timestamp":1651297447000},"page":"689","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["The Effect of Normobaric Hypoxia in Middle- and\/or Long-Distance Runners: Systematic Review"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8121-0290","authenticated-orcid":false,"given":"In\u00e9s","family":"Albertus-C\u00e1mara","sequence":"first","affiliation":[{"name":"Research Group of Physical Exercise and Human Performance, Mare Nostrum Campus, University of Murcia, 30100 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vicente","family":"Ferrer-L\u00f3pez","sequence":"additional","affiliation":[{"name":"Research Group of Physical Exercise and Human Performance, Mare Nostrum Campus, University of Murcia, 30100 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3664-2115","authenticated-orcid":false,"given":"Ignacio","family":"Mart\u00ednez-Gonz\u00e1lez-Moro","sequence":"additional","affiliation":[{"name":"Research Group of Physical Exercise and Human Performance, Mare Nostrum Campus, University of Murcia, 30100 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.neubiorev.2017.01.019","article-title":"Effect of acute hypoxia on cognition: A systematic review and meta-regression analysis","volume":"74","author":"McMorris","year":"2017","journal-title":"Neurosci Biobehav. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"975","DOI":"10.3357\/ASEM.3315.2012","article-title":"Hypoxic hypoxia at moderate altitudes: Review of the state of the science","volume":"83","author":"Petrassi","year":"2012","journal-title":"Aviat. Space Environ. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1258","DOI":"10.1152\/japplphysiol.00359.2005","article-title":"Exercise training in normobaric hypoxia in endurance runners. III. Muscular adjustments of selected gene transcripts","volume":"100","author":"Zoll","year":"2006","journal-title":"J. Appl. Physiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1152\/jappl.2001.91.1.173","article-title":"Molecular adaptations in human skeletal muscle to endurance training under simulated hypoxic conditions","volume":"91","author":"Vogt","year":"2001","journal-title":"J. Appl. Physiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1123\/ijspp.5.4.497","article-title":"Hypoxia Increases Muscle Hypertrophy Induced by Resistance Training","volume":"5","author":"Nishimura","year":"2010","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1767","DOI":"10.1007\/s00421-013-2605-z","article-title":"Effects of resistance training combined with vascular occlusion or hypoxia on neuromuscular function in athletes","volume":"113","author":"Manimmanakorn","year":"2013","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1097\/00005768-199903000-00018","article-title":"Design and analysis of research on sport performance enhancement","volume":"31","author":"Hopkins","year":"1999","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1610","DOI":"10.1249\/mss.0b013e3180de49e6","article-title":"Application of altitude\/hypoxic training by elite athletes","volume":"39","author":"Wilber","year":"2007","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Ambro\u017cy, T., Maciejczyk, M., Klimek, A.T., Wiecha, S., Stanula, A., Snopkowski, P., Pa\u0142ka, T., Jaworski, J., Ambro\u017cy, D., and Rydzik, \u0141. (2020). The Effects of Intermittent Hypoxic Training on Anaerobic and Aerobic Power in Boxers. Int. J. Environ. Res. Public Health, 17.","DOI":"10.3390\/ijerph17249361"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1152\/jappl.1997.83.1.102","article-title":"Living high-training low: Effect of moderate-altitude acclimatization with low-altitude training on performance","volume":"83","author":"Levine","year":"1997","journal-title":"J. Appl. Physiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1089\/15270290260131911","article-title":"Intermittent Hypoxic Training: Fact and Fancy","volume":"3","author":"Levine","year":"2002","journal-title":"High Alt. Med. Biol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1590","DOI":"10.1249\/mss.0b013e3180de49bd","article-title":"Effect of Hypoxic Dose on Physiological Responses and Sea-Level Performance","volume":"39","author":"Wilber","year":"2007","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"i31","DOI":"10.1136\/bjsports-2013-092840","article-title":"Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis","volume":"47","author":"Gore","year":"2013","journal-title":"Br. J. Sports Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1007\/s40279-014-0177-7","article-title":"Hypoxia and Resistance Exercise: A Comparison of Localized and Systemic Methods","volume":"44","author":"Scott","year":"2014","journal-title":"Sports Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1123\/ijspp.8.4.391","article-title":"Physiological and Performance Responses to a Preseason Altitude-Training Camp in Elite Team-Sport Athletes","volume":"8","author":"McLean","year":"2013","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2165\/11317920-000000000-00000","article-title":"Combining Hypoxic Methods for Peak Performance","volume":"40","author":"Millet","year":"2010","journal-title":"Sports Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"107","DOI":"10.2165\/00007256-200939020-00002","article-title":"Sea-Level Exercise Performance Following Adaptation to Hypoxia","volume":"39","author":"Bonetti","year":"2009","journal-title":"Sports Med."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Moher, D., Liberati, A., Tetzlaff, J., Altman, D.G., and PRISMA Group (2009). Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med., 6.","DOI":"10.1371\/journal.pmed.1000097"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1093\/ptj\/83.8.713","article-title":"Reliability of the PEDro Scale for Rating Quality of Randomized Controlled Trials","volume":"83","author":"Maher","year":"2003","journal-title":"Phys. Ther."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1800","DOI":"10.1152\/japplphysiol.00969.2003","article-title":"Intermittent normobaric hypoxia does not alter performance or erythropoietic markers in highly trained distance runners","volume":"96","author":"Julian","year":"2004","journal-title":"J. Appl. Physiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"112611","DOI":"10.1016\/j.physbeh.2019.112611","article-title":"Psycho-physiological responses to perceptually-regulated interval runs in hypoxia and normoxia","volume":"209","author":"Hobbins","year":"2019","journal-title":"Physiol. Behav."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1152\/japplphysiol.00808.2005","article-title":"Eighteen days of living high, training low stimulate erythropoiesis and enhance aerobic performance in elite middle-distance runners","volume":"100","author":"Brugniaux","year":"2006","journal-title":"J. Appl. Physiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"630","DOI":"10.3389\/fphys.2020.00630","article-title":"Effect of Acute Hypoxia on Cardiorespiratory Coherence in Male Runners","volume":"11","author":"Uryumtsev","year":"2020","journal-title":"Front. Physiol."},{"key":"ref_24","first-page":"644","article-title":"Effects of Intermittent Hypoxia on Running Economy","volume":"31","author":"Burtscher","year":"2010","journal-title":"Laryngo-Rhino-Otologie"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1238","DOI":"10.1152\/japplphysiol.00742.2005","article-title":"Exercise training in normobaric hypoxia in endurance runners. I. Improvement in aerobic performance capacity","volume":"100","author":"Dufour","year":"2006","journal-title":"J. Appl. Physiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2309","DOI":"10.1519\/JSC.0b013e318295d338","article-title":"Effects of Normobaric Hypoxia Equivalent to 2,000-m Altitude on Sleep and Physiological Conditions of Athletes","volume":"27","author":"Hoshikawa","year":"2013","journal-title":"J. Strength Cond. Res."},{"key":"ref_27","first-page":"75","article-title":"Effect of intermittent hypoxia on oxygen uptake during submaximal exercise in endurance athletes","volume":"92","author":"Katayama","year":"2004","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.resp.2004.11.007","article-title":"Changes in ventilatory responses to hypercapnia and hypoxia after intermittent hypoxia in humans","volume":"146","author":"Katayama","year":"2005","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"828","DOI":"10.1152\/japplphysiol.00265.2007","article-title":"The effects of nightly normobaric hypoxia and high intensity training under intermittent normobaric hypoxia on running economy and hemoglobin mass","volume":"103","author":"Neya","year":"2007","journal-title":"J. Appl. Physiol."},{"key":"ref_30","first-page":"379","article-title":"Effectiveness of intermittent training in hypoxia combined with live high\/train low","volume":"110","author":"Robertson","year":"2010","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1249\/MSS.0b013e3181b34b57","article-title":"Reproducibility of Performance Changes to Simulated Live High\/Train Low Altitude","volume":"42","author":"Robertson","year":"2010","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/j.pcad.2010.02.013","article-title":"Is Hypoxia Training Good for Muscles and Exercise Performance?","volume":"52","author":"Vogt","year":"2010","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref_33","first-page":"471","article-title":"Effects of physical training in a hypobaric chamber on the physical performance of competitive triathletes","volume":"73","author":"Vallier","year":"1996","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1089\/152702903769192250","article-title":"Intermittent Hypoxia Improves Endurance Performance and Submaximal Exercise Efficiency","volume":"4","author":"Katayama","year":"2003","journal-title":"High Alt. Med. Biol."},{"key":"ref_35","first-page":"708","article-title":"Effects of Normobaric Hypoxia on Matched-severe Exercise and Power-duration Relationship","volume":"42","author":"Sousa","year":"2021","journal-title":"Laryngo-Rhino-Otologie"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1007\/s004210050621","article-title":"Live high, train low does not change the total hemoglobin mass of male endurance athletes sleeping at a simulated altitude of 3000m for 23 nights","volume":"80","author":"Ashenden","year":"1999","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"S86","DOI":"10.1097\/00005768-199905001-00277","article-title":"Effect of living in hypoxia and training in normoxia on sea level VO2max and red cell mass","volume":"31","author":"Rusko","year":"1999","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2005","DOI":"10.1152\/japplphysiol.00315.2007","article-title":"Changes in sleep quality of athletes under normobaric hypoxia equivalent to 2,000-m altitude: A polysomnographic study","volume":"103","author":"Hoshikawa","year":"2007","journal-title":"J. Appl. Physiol."},{"key":"ref_39","first-page":"1279","article-title":"Adaptations to high-intensity training are independent of gender","volume":"111","author":"Astorino","year":"2011","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_40","first-page":"472","article-title":"Effects of a 12-day \u201clive high, train low\u201d camp on reticulocyte production and haemoglobin mass in elite female road cyclists","volume":"80","author":"Ashenden","year":"1999","journal-title":"Graefe\u2019s Arch. Clin. Exp. Ophthalmol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1007\/s00421-006-0240-7","article-title":"Living high-training low: Effect on erythropoiesis and maximal aerobic performance in elite Nordic skiers","volume":"97","author":"Robach","year":"2006","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"931","DOI":"10.1152\/japplphysiol.00725.2003","article-title":"Improved running economy in elite runners after 20 days of simulated moderate-altitude exposure","volume":"96","author":"Saunders","year":"2004","journal-title":"J. Appl. Physiol."}],"container-title":["Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-7737\/11\/5\/689\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:04:47Z","timestamp":1760137487000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-7737\/11\/5\/689"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,4,30]]},"references-count":42,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["biology11050689"],"URL":"https:\/\/doi.org\/10.3390\/biology11050689","relation":{},"ISSN":["2079-7737"],"issn-type":[{"value":"2079-7737","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,4,30]]}}}