Workouts are essential parts of any serious car racer's regimen, but Hunter-Reay adds an underwater twist by free diving – that is, submersing while holding his breath. What motivates him to reach depths between 25 and 65 feet below the surface? Spearfishing is most effective at those depths. "It's a good cardio workout that helps you build lung capacity," he comments. "I think that helps in the car, too."