You don’t need one to start but a watch or bike computer can make training easier, more consistent, and more repeatable. Think of it like this: it won’t create fitness, but it helps you execute the right workout at the right effort. When it’s worth buying You train alone and want better pacing (easy stays easy, hard stays controlled) You like structure (intervals, target pace/HR/power, workout prompts) You want reliable tracking (distance, time, trends, progress) You’re doing longer rides and want navigation + ride data visible without stopping When you can skip it for now You’re just getting started and your main goal is consistency Budget is tight (shoes, comfort, and safety gear matter more early) You feel overwhelmed by data and just want to train by effort Watch vs bike computer (which is better?) A watch is best if: You want one device for run + swim + general training You want heart rate, pace, and basic structure on the run You’re doing pool tracking and want simple swim metrics A bike computer is best if: Cycling is a big focus (especially for 70.3/Ironman) You want a bigger screen for power/HR, lap intervals, and navigation You ride outdoors a lot and want safer “eyes up” visibility Many triathletes end up with both eventually but if you’re buying only one: Sprint/Olympic beginners: a watch usually gives the most value. 70.3/Ironman focused: a bike computer becomes very useful, especially with longer rides. Some Smart Watches also offer bike mounts where you can transiiton the watch to and from the bike during T1 and T2 Smart buying tips Buy for comfort and usability, not max features. If possible, get something that supports: Structured workouts GPS + lap button Heart rate compatibility (even if you add a strap later) Practice with it in training, not for the first time on race week. Bottom line: not mandatory but if you like structure and feedback, it’s one of the most useful upgrades you can make for consistent training.