The cyclists were given either 4mg/day of an astaxanthin extract supplied by Swedish supplier BioReal or placebo for 28 days, with the astaxanthin group showing better endurance and power in a 20km time trial (TT).
But they observed: “The mechanism of action for these improvements remains unclear, as we observed no treatment effects for carbohydrate and fat oxidation, or blood indices indicative of fuel mobilization. While AST significantly improved TT performance the mechanism of action explaining this effect remains obscure.”
Published in the International Journal of Sports Medicine , the research tested for various indices like VO2max and lactate thresholds with riders between the ages of 18-39 that had to complete the 20km TT following a two-hour pre-exhaustion ride following a 10-hour fast.
“The goal in using this type of protocol was to minimize the contributions of carbohydrate for energy provision; hence, creating an increased reliance on fat oxidation,” the researchers wrote.
While only seven riders completed the study in each of the astaxanthin and placebo groups, the astaxanthin group showed a 5% (2-minute) improvement and a 15% (20 watt) improvement in power output.
“…the plaecbo group showed minimal improvements and were fairly evenly split between faster and slower performances,” the researchers said. “Despite these improvements in cycling performance the mechanism of action to explain our findings remain enigmatic.”
They added: “Though we were successful in demonstrating that AST appears to have an ergogenic effect, we acknowledge that the true effectiveness of AST supplementation relative to competitive exercise performance is not yet known given that our feeding schema does not adequately represent dietary practices associated with competition.”
“If fat metabolism is of future research interest, those investigators undertaking that task may wish to consider a lower intensity exercise regime more closely identified with the purported range of maximal fat oxidation."
“If performance is an area of interest, we suggest that these issues be examined under conditions more closely related to feeding strategies of those athletes engaged in the sport of interest.”
International Journal of Sports Medicine
‘Effect of Astaxanthin on Cycling Time Trial Performance’
Authors: C. P. Earnest, M. Lupo, K. M. White, T. S. Church