Two-time Ironman Hawaii World Champion Craig Alexander doesn't just train with power. He samples his power data along a blood lactate curve to analyze, in-depth, how his body responds to increasing amounts of load. Earlier in the season, his top-end power was higher, meaning he could generate a high power for a longer period of time without as much lactate buildup. Now, as ne's focusing on defending his Ironman Hawaii title to take his third crown, he needs to be able to hold his mid-range power for longer. The lactate test reveals where he is with his form, and how his training has affected that curve.