The benefits of astaxanthin on exercise performance are very positive, though most information about its effectiveness at increasing strength and endurance is anecdotal. The best human clinical study shows that astaxanthin increased strength and endurance by 55%. See full article on this study here.
In terms of human clinical trials, there is evidence of improved physical strength from taking astaxanthin. For example, Swedish researchers divided 40 students into two groups, with half taking astaxanthin daily and the other half getting a placebo.1 Standardized exercise tests after three and six months of supplementation demonstrated a significant difference in strength and endurance between the two groups, with the astaxanthin group performing with a superior results. Another such study is due out mid 2011 that is expected to bolster these findings.
Astaxanthin reduces fat
According to animal models, astaxanthin supplementation increases endurance capacity and significantly decreases the accumulation of fat.2 Be aware that animal models don't necessarily translate to humans, but they reveal the mechanisms that are at work in living things, and scientists use animal models as a precursor to testing in humans for that very reason.
In another mice testing regimen, mice were divided into four different groups: sedentary, sedentary treated with astaxanthin, running exercise, and exercise treated with astaxanthin. After four weeks of treatment, exercise groups performed treadmill running. Astaxanthin increased fat utilization (as opposed to glucose utilization) during exercise compared with mice on a normal diet.3
The benefits of astaxanthin on exercise performance are very positive, though most information about its effectiveness at increasing strength and endurance is anecdotal. The best human clinical study shows that astaxanthin increased strength and endurance by 55%. 
