Serious triathletes may be the most tech-savvy of all athletes. You have the latest devices and know that data to improve your performance are at hand, but putting it all together can be a daunting, confusing task.

Triathlete, coach, researcher, and author Jim Vance maintains that, despite access to the relevant information, most triathletes start a race undertrained or overtrained. That's why he's developed Triathlon 2.0: Data-Driven Performance Training, the first program to take advantage of the latest science and technology.

Triathlon 2.0 examines the...