Inside Tracker, a service used by Olympians to improve internal health (and thereby performance)

To help prepare for track meets, competitive 5K races and especially the Olympics, Boston-based runner Ruben Sanca runs 116 miles per week, takes vitamins and mostly watches his diet. But he would still feel fatigued after training runs. Then a blood analysis and a special software program revealed his internal chemistry needed some adjusting. Read Popular Science and see InsideTracker.