Thirty-two well-trained male cyclists ( age 255 , weight 737 kg , maximum O2 uptake 605 mLkg ( -1 ) min ( -1 ) , Wmax 5.40.5 Wkg ( -1 ) ; mean SD ) were repeatedly subjected to a laboratory based standardized exercise protocol before and after 4 weeks of astaxanthin ( 20 mg/day ) , or placebo supplementation in a double-blind randomized manner .