Algae: the next big ‘superfood’ for athletes? - by Tom Gurney

Over the past few years, global demand for edible algae has slowly increased and algae is now being consumed for reasons other than the traditional benefits for nutrition and health. Both spirulina and chlorella are unique green-blue freshwater algae that grow and thrive naturally in warm lakes, but are also commercially produced outdoors in large ponds.

The recent upsurge in attention towards these products has meant that the majority of keen sport nutritionists, athletes and sport enthusiasts have heard of spirulina. However, when many athletes hear about the potential health and ergogenic aid capabilities of algae, they instantly turn their nose up. Supposedly, the consumption of green-blue dried algae isn’t the most appealing, yet spirulina and chlorella have both been classified as ‘superfoods’ because they contain an exceptionally rich amount of vitamins, amino acids and iron. Surely if athletes and budding nutritionists know that, we may see a shift in attitudes?

Due to their ‘superfood’ status, spirulina and chlorella’s nutritional capabilities have been extensively researched within a clinical health setting. An abundance of positive reports predominantly indicates the improvement of anaemia, obesity, a range of cardiovascular risk factors, such as hypertension and atrial stiffness, and the deterrence of fatty liver disease. Thus far, only a handful of studies have tried to bridge the gap between these clinical findings and the potential ergogenic effect of these algae for athletes.

The paucity of attention focused on algae and its ergogenic capabilities for athletes begs several questions: can spirulina and/or chlorella conjunctively improve health and ergogenic parameters of an athlete? What athlete population responds the best? What does the research so far suggest?


Studies by Kalafati et al (1) and Lu et al (2) focused on the antioxidative properties of spirulina. Both researchers reported spirulina to increase the time to exhaustion in runners. Kalafati et al attributed the findings to increases in glutathione (GSH), which had previously been identified to modulate oxidative stress. But Lu et al attributed their findings to spirulina reducing the pre-oxidative levels in muscles during exhaustive exercise, predominantly due to the decrease in malondialdehyde (a metabolite derived from phospholipid peroxidation that causes toxic stress in cells and is a common indicator of oxidative stress).

However, Franca et al (3) concluded that spirulina supplementation had no significant ergogenic effects on chronic muscle damage and oxidative stress in highly trained cyclists after high-volume intensity training. This perhaps suggests that highly trained athletes with a high nutritional status (antioxidant status within normal range) will experience no significant ergogenic effect from spirulina.


Supplementing chlorella at 6g/day for four weeks significantly improved maximal oxygen uptake in cycling, predominantly attributed to chlorella significantly improving the nutritional status of participants (4). Chlorella intake has also been shown to significantly increase both mice and rats’ ability to complete a maximal number of HIT tests (5,6). Findings were attributed to the enhanced activity of lactate dehydrogenase (LDH) and the increase in fatty acid metabolism, suggesting improvements in the uptake and buffering capability of lactate in working skeletal muscles. LDH activation decreases blood lactate concentrations via the conversion of lactate into pyruvate, which then undergoes degradation via the Krebs cycle.

There were further increases in PGC-1α after the intake of chlorella. PGC-1α facilitates mitochondrial biogenesis and oxidative metabolism. Therefore, increases in PGC-1α suggest that the intervention of chlorella promotes the oxidation of lactate. Efficient lactate production and removal is particularly important for team sports or cycling, where a common prerequisite is to produce high-intensity sprints with the ability to use brief recovery periods to buffer the raised lactate levels. Fatigue resistance and the ability to replicate high-intensity efforts are considered a fundamental part of team sports and cycling. Therefore, any supplement that may contain performance-enhancing properties during intermittent sprint performances, such as lactate clearance or increasing maximal oxygen uptake from the intake of microalgae, could be highly sought after.


Despite minimal side effects reported by athletes, unless you like the taste of algae, capsule form may be the only reasonable way to ingest it. However, to ingest a relatively small daily dose of 6g, athletes would have to take up to 12 capsules a day, which seems excessive.

That said, if it gives athletes a one to two per cent increase in performance, the nuisance of taking 12 capsules a day may be worth considering several weeks prior to competition.

Ultimately, any improvements in exercise performance from algae supplementation is sporadic. Notably, research is at its early stages and due to algae being a multicomponent species, it is hard to pinpoint the exact mechanisms behind research findings. Research does suggest that recreational athletes may benefit the most from supplementing with 6-7g/day for at least two weeks.

Due to a distinct lack of research within the sport nutritional algae remit, within my PhD research at Kingston University, I am now investigating the effects of microalgae on exercise performance. My research project last year found significant increases in haemoglobin and VO2max scores in recreationally active males on the arm crank ergometer (unpublished data). This year, I am researching the lactate clearance capabilities of both spirulina and chlorella in cyclists. An interesting avenue yet to be explored is anaemic females and exercise performance. With such a high prevalence of anaemia in sporting females, if spirulina or chlorella can significantly improve anaemia, what could this also do for female performance?

To find out more about Tom Gurney’s research, you can email him here.

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  1. Kalafati et al (2010). Ergogenic and antioxidant effects of spirulina supplementation in humans. Med Sci Sport Exerc. 42(1):142-151.
  2. Lu HK et al (2006). Preventive effects of Spirulina platensis on skeletal muscle damage under exercise-induced oxidative stress. Eur J Appl Physiol. 98(2): 220.
  3. Franca AS et al (2010). Spirulina does not decrease muscle damage nor oxidative stress in cycling athletes with adequate nutritional status. Biol Sport. 27(4):249-253.
  4. Umemoto S & Otsuki T (2014). Chlorella-derived multicomponent supplementation increases aerobic endurance capacity in young individuals. J Clin Biochem Nutr. 55(2):143-146.
  5. Horii N et al (2017). High-intensity intermittent exercise training with chlorella intake accelerates exercise performance and muscle glycolytic and oxidative capacity in rats. Am J Physiol Regul Integr Comp Physiol. 312(4):520-528.
  6. Mizoguch T et al (2011). Influence of Chlorella powder intake during swimming stress in mice. Biochem Biophys Res Commun. 404(1):121-126.