Spirulina and arm cycling oxygen use in men
What it found
In eleven untrained men, taking spirulina for seven days raised hemoglobin and lowered oxygen uptake and heart rate during arm cycling.
Oxygen uptake at the point of fatigue was higher after spirulina.
What they found
Studies in people
Hemoglobin increase
After spirulina, hemoglobin was significantly higher than after placebo (154.5 g/l vs 144.1 g/l).
Oxygen uptake during submaximal exercise
During the 30-minute submaximal arm cycling, average oxygen uptake was significantly lower after spirulina than placebo (2170 ml/min vs 2311 ml/min).
Heart rate during submaximal exercise
Average heart rate during the 30-minute submaximal exercise was significantly lower after spirulina than placebo (149 bpm vs 154 bpm).
Oxygen uptake at fatigue
Oxygen uptake at the point of fatigue was significantly higher after spirulina than placebo (37.37 ml/min/kg vs 34.10 ml/min/kg).
Time to fatigue
Time taken to reach fatigue was not significantly different between spirulina and placebo (530 s vs 503 s).
Respiratory exchange ratio
Respiratory exchange ratio during submaximal exercise was not significantly different between spirulina and placebo (1.00 vs 1.01).
What the authors conclude
“Spirulina supplementation significantly reduces oxygen uptake and HR during arm cycling submaximal exercise, allowing for an increased oxygen uptake during an incremental test to fatigue.”
Also in their conclusions
- They conclude that seven days of spirulina supplementation at 6 g per day significantly increased hemoglobin and reduced oxygen uptake and heart rate during arm cycling submaximal exercise.
- They state that this allowed for an increased oxygen uptake during an incremental test to fatigue.
- They suggest that spirulina can be considered an effective ergogenic aid for both submaximal and maximal intensities, particularly for arm cycling exercise modalities.
How it was done
Spirulina has been reported to improve high-intensity exercise and hemoglobin, but its effect on arm cycling exercise had not been investigated. The authors wanted to see how spirulina supplementation affects hemoglobin and oxygen uptake, RER and heart rate during seated arm cycling.
Eleven healthy males unfamiliar with arm cycling took 6 g a day of spirulina or a placebo for seven days in a double-blinded randomized crossover design. They did 30-minute submaximal arm cycling bouts at 55% of their maximal oxygen uptake, followed by an incremental test to fatigue, with a seven-day wash-out between conditions.
What it can’t tell you
- The study included only eleven untrained men, so the results may not apply to women or trained athletes.
- The study lasted only seven days, so it cannot show what happens with longer-term spirulina use.
- The authors did not measure antioxidant effects or other possible mechanisms, so they cannot say exactly how spirulina caused these changes.
Who paid
- Conflicts
- The authors declare that they have no conflicts of interest to report.
- Authors work at
- Kingston University, UK
The paper
- Title
- Spirulina supplementation improves oxygen uptake in arm cycling exercise
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Gurney T, Spendiff O (2020). Spirulina supplementation improves oxygen uptake in arm cycling exercise. European journal of applied physiology. doi:10.1007/s00421-020-04487-2Free full textPubMed 32892320DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error