The reason for the boom in triathlon popularity comes down to one factor: distance. Specifically, the greater number of sprint-distance events. The shorter legs—typically a half-mile swim, 12-mile bike ride, and three-mile run—are as attractive to timid newbies (“Hey, I can do that”) as they are to hard-charging competitors (“I’m gonna redline the whole way!”). Almost anyone can make it to the finish line, but how fast you get there can result in a dramatically different kind of race.

Not that it’s ever easy. “Just because it’s ­labeled a sprint doesn’t mean it isn’t challenging,” says Matt Dixon, a coach and former pro triathlete. “It’s going to take even the most accomplished athlete more than an hour of racing—that’s not short.”

For first-timers, building balanced endurance fitness, honing a race strategy, and practicing transitions will make the race go faster and boost your enjoyment. You’ll taste the unique thrill of multisport racing and—perhaps even more addictive—reap the physical and mental benefits of cross-training.

Have your eyes set on an Ironman? Top coaches like Dixon and Joe Friel, author of The Triathlete’s Training Bible, still recommend you start small. “Gradually working up to longer distances is the healthy way to do it,” says Friel, who advises new athletes to stick with sprint races for their first year. And once you’ve moved up to longer events, he still recommends regular participation in sprints. “Not only are they good for developing speed,” he says, “they’re also good mental tune-ups for bigger races.”