{"title":"Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial.","authors":"Tom Gurney, James Brouner, Owen Spendiff","doi":"10.1080/15502783.2025.2498484","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Existing literature indicates that spirulina supplementation can improve a variety of blood morphological parameters (such as hemoglobin) in healthy and clinical populations. Given the importance of hemoglobin for endurance exercise, particularly at altitude, this study aimed to investigate whether spirulina supplementation can improve blood morphological parameters in healthy cyclists and positively influence physiological variables when completing a lactate threshold test at simulated moderate altitude (2,500 m).</p><p><strong>Methods: </strong>Twenty (18 male; 2 female) healthy participants (Mean ± SD; Age 37 ± 9 years, Stature 181 ± 6 cm, Mass 81 ± 9 kg, <math><mrow><mover><mi>V</mi><mo>˙</mo></mover></mrow></math>O<sub>2max</sub> 51.8 ± 7.8 ml·kg-1·min-1) ingested 6 g/day of spirulina or placebo for 3-weeks in a double-blinded randomized counter-balanced cross-over design, then completed a lactate threshold test at simulated moderate altitude, with a 14-day washout period between trials.</p><p><strong>Results: </strong>Following spirulina supplementation, heart rate at the lactate threshold was significantly lower in comparison to placebo supplementation (spirulina = 152 ± 11 b.min -1 vs. placebo = 155 ± 12 b.min -1, <i>p</i> < 0.05). No other physiological variables (Watts, RER, RPE, VO<sub>2</sub>) were significantly different (<i>p</i> > 0.05) at the calculated threshold, or during the first four lower stages. Red Cell Distribution Width significantly increased following spirulina supplementation in comparison to placebo (spirulina = 13.3 ± 0.9 % vs. placebo = 12.5 ± 0.7 %, <i>p</i> < 0.05). Plateletcrit significantly decreased following spirulina supplementation (spirulina = 0.288 ± 0.032 vs. placebo = 0.293 ± 0.050, <i>p</i> < 0.05). No other blood morphological parameters changed (<i>p</i> > 0.05).</p><p><strong>Conclusion: </strong>In conclusion, three weeks of spirulina supplementation at 6 g/day reduced heart rate during a lactate threshold test at a simulated moderate altitude (2,500 m), but did not produce additional physiological or hematological benefits.</p>","PeriodicalId":17400,"journal":{"name":"Journal of the International Society of Sports Nutrition","volume":"22 1","pages":"2498484"},"PeriodicalIF":4.5000,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12046610/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the International Society of Sports Nutrition","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1080/15502783.2025.2498484","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/5/1 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"NUTRITION & DIETETICS","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Existing literature indicates that spirulina supplementation can improve a variety of blood morphological parameters (such as hemoglobin) in healthy and clinical populations. Given the importance of hemoglobin for endurance exercise, particularly at altitude, this study aimed to investigate whether spirulina supplementation can improve blood morphological parameters in healthy cyclists and positively influence physiological variables when completing a lactate threshold test at simulated moderate altitude (2,500 m).
Methods: Twenty (18 male; 2 female) healthy participants (Mean ± SD; Age 37 ± 9 years, Stature 181 ± 6 cm, Mass 81 ± 9 kg, O2max 51.8 ± 7.8 ml·kg-1·min-1) ingested 6 g/day of spirulina or placebo for 3-weeks in a double-blinded randomized counter-balanced cross-over design, then completed a lactate threshold test at simulated moderate altitude, with a 14-day washout period between trials.
Results: Following spirulina supplementation, heart rate at the lactate threshold was significantly lower in comparison to placebo supplementation (spirulina = 152 ± 11 b.min -1 vs. placebo = 155 ± 12 b.min -1, p < 0.05). No other physiological variables (Watts, RER, RPE, VO2) were significantly different (p > 0.05) at the calculated threshold, or during the first four lower stages. Red Cell Distribution Width significantly increased following spirulina supplementation in comparison to placebo (spirulina = 13.3 ± 0.9 % vs. placebo = 12.5 ± 0.7 %, p < 0.05). Plateletcrit significantly decreased following spirulina supplementation (spirulina = 0.288 ± 0.032 vs. placebo = 0.293 ± 0.050, p < 0.05). No other blood morphological parameters changed (p > 0.05).
Conclusion: In conclusion, three weeks of spirulina supplementation at 6 g/day reduced heart rate during a lactate threshold test at a simulated moderate altitude (2,500 m), but did not produce additional physiological or hematological benefits.
期刊介绍:
Journal of the International Society of Sports Nutrition (JISSN) focuses on the acute and chronic effects of sports nutrition and supplementation strategies on body composition, physical performance and metabolism. JISSN is aimed at researchers and sport enthusiasts focused on delivering knowledge on exercise and nutrition on health, disease, rehabilitation, training, and performance. The journal provides a platform on which readers can determine nutritional strategies that may enhance exercise and/or training adaptations leading to improved health and performance.