Chlorella supplementation may boost cycling performance: RCT

Three weeks of supplementation with chlorella may improve relative power during repeated cycling sprints, and lower average lactate and heart rate during endurance tests, says a new study from England.

Six grams per day of chlorella for 21 days was also associated with higher hemoglobin levels, compared to placebo, according to data published in the Journal of Dietary Supplements.

However, no improvements were observed for time trials or lactate thresholds, reported researchers from the University of Kingston.

“The novel findings of this study indicate that 6 g/day chlorella supplementation for 21-days can significantly improve relative power during RSPTs [repeated sprint performance tests] and allow submaximal exercise to be performed with lower homeostatic disturbances,” they wrote.

“Chlorella may therefore pose as an additional supplement for cyclists to consider, particularly for those cyclists who want to improve their sprinting.”

Chlorella

Chlorella was amongst the first algae to be cultivated for food supplement purposes. Industrial production of Chlorella began in Japan shortly after the Second World War. The alga is a rich source of amino acids, protein, minerals, vitamins, dietary fiber, antioxidants and other bioactive substances.

Microalgae is an emerging functional food source that is gaining traction and popularity in biopharmaceutical, nutraceutical, and sport and exercise nutrition field. Since most research within the sport and exercise nutrition field has focused on spirulina’s effects on exercise performance, the researchers believed “it’s worthy to investigate whether chlorella has analogous function and potential during exercise.”

“This is the first study to investigate the influences of chlorella supplementation on key physiological responses in trained cyclists during a submaximal endurance test,” noted the authors, led by Tom Gurney.

Study details

This double-blinded randomized counter-balanced cross-over design study included 14 male trained cyclists randomly assigned to receive either placebo or chlorella supplements (Indigo Herbs Limited) for 21 days. This was followed by a 14-day washout period before the participants crossed over to the other intervention.

Each participant completed a 2-day testing period comprising a 1-hour submaximal endurance test at 55% external power output max and a 16.1 km time trial, followed by a lactate threshold and repeated sprint performance tests. Heart rate, lactate and glucose, time, power output, and hemoglobin were compared across conditions.

Results showed that chlorella supplementation significantly lowered average lactate and heart rate during submaximal endurance tests, average power and peak power were significantly higher during repeated sprint bouts, and hemoglobin significantly increased in comparison to placebo.

However, no differences existed between conditions for all oxygen consumption values, 16.1 km time trial measures and lactate threshold tests.

This applied performance data provides further evidence in the possible efficacy of chlorella supplementation in the sport and exercise nutrition field. Further mechanistic research is warranted to explore the speculations, as currently conclusive interpretation of the results is limited.

Source: Journal of Dietary Supplements
Published online ahead of print, doi: 10.1080/19390211.2023.2186557
“The Efficacy of Chlorella Supplementation on Multiple Indices of Cycling Performance.”
Authors: T. Gurney, et al.