How to Choose the Right Fitness Tracker for Your Training Goals | Power Athlete

These days, we’re surrounded by fitness tech, some helpful, some just hype. From budget-friendly wristbands that monitor your heart rate to $2,000+ Garmin watches tracking everything from sleep stages to Pulse Ox, the options can be overwhelming. This article breaks down the core differences between these devices, what features to look for, and how to choose the right one for your training goals.

Heart Rate Monitoring: Optical vs. ECG

The most common feature across all wrist-based fitness trackers is heart rate (HR) monitoring. Most devices use optical sensors, which work by shining light into your skin to measure blood flow. A less common, but more medically accurate, method is ECG (electrocardiography), which uses electrode sensors to detect the heart’s electrical activity.

While ECG sensors are becoming more common, most smartwatches still rely primarily on optical sensors for day-to-day heart rate tracking. That’s because optical monitoring is less power-intensive and allows for continuous tracking without draining the battery.

Accuracy tip: Optical sensors can struggle with accuracy if you have tattoos under your watch or during high-intensity activity. For casual, daily use, they’re generally reliable, but if you’re serious about training…

Step It Up: Use a Chest Strap

If you want accurate heart rate data during workouts, a chest strap HR monitor is the gold standard. Most quality smartwatches can pair with a chest strap via Bluetooth or ANT+. I use one for all activity to include Brazilian jiu-jitsu sessions. It's great, unless it gets knocked loose during a roll.

GPS and Accelerometers: The Other Core Sensors

Beyond heart rate, smartwatches gather training data using GPS and accelerometers. These are the other key sensors we’ll focus on in this series:

Understanding how your watch collects and processes this data is crucial for using it effectively, which we’ll dig into in Part 2 of this series.

Bill Williams is a former U.S. Army infantryman and current quality engineer who brings a powerful blend of leadership, discipline, and athletic grit to everything he does. A husband and proud father of four daughters, he holds a Bachelor’s in Aerospace Engineering from Embry-Riddle, a Master’s in Engineering and Technical Management from Texas A&M, and an MBA from UT Dallas.Outside of his professional life, Bill is a certified Power Athlete Block One Coach and lifelong competitor. From playing college rugby and representing the Fort Benning men’s team to stepping onto the mats as a Brazilian Jiu-Jitsu white belt, he thrives in high-performance spaces that demand toughness, teamwork, and relentless growth.Whether he’s training, parenting, or leading in the workplace, Bill leads with purpose—and lives to push the limits of what’s possible.