Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial

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 investiga...

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Main Authors: Tom Gurney, James Brouner, Owen Spendiff
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
Series:Journal of the International Society of Sports Nutrition
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Online Access:https://www.tandfonline.com/doi/10.1080/15502783.2025.2498484
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author Tom Gurney
James Brouner
Owen Spendiff
author_facet Tom Gurney
James Brouner
Owen Spendiff
author_sort Tom Gurney
collection DOAJ
description 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, [Formula: see text]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.
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spelling doaj-art-3771beaf23fc4b00b586d34855fda5762025-08-20T03:49:08ZengTaylor & Francis GroupJournal of the International Society of Sports Nutrition1550-27832025-12-0122110.1080/15502783.2025.2498484Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trialTom Gurney0James Brouner1Owen Spendiff2Kingston University, School of Life Sciences, Kingston upon Thames, EnglandKingston University, School of Life Sciences, Kingston upon Thames, EnglandKingston University, School of Life Sciences, Kingston upon Thames, EnglandBackground 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, [Formula: see text]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.https://www.tandfonline.com/doi/10.1080/15502783.2025.2498484Altitudealgaecyclinglactateheart rate
spellingShingle Tom Gurney
James Brouner
Owen Spendiff
Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
Journal of the International Society of Sports Nutrition
Altitude
algae
cycling
lactate
heart rate
title Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
title_full Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
title_fullStr Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
title_full_unstemmed Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
title_short Physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude (2,500 m): a randomized controlled trial
title_sort physiological effects of spirulina supplementation during lactate threshold exercise at simulated altitude 2 500 m a randomized controlled trial
topic Altitude
algae
cycling
lactate
heart rate
url https://www.tandfonline.com/doi/10.1080/15502783.2025.2498484
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