It started with an ordinary purchase. Steven Luemba decided to buy an Apple Watch in 2019 while living in London. For a while, it seemed like just another gadget, tracking steps and delivering notifications. Then one day in 2020, the watch chimed with a notification that would change everything. It alerted him to an irregular heart rhythm—atrial fibrillation.

At first, Steven didn’t think much of it. But as the notifications persisted, he decided to visit a doctor. That decision saved his life. The atrial fibrillation was confirmed, and timely medical treatment prevented a potentially fatal outcome.

Steven’s story is a powerful reminder of how wearables can be more than just tech accessories; they can be life-saving tools. Yet for most people, these devices come with an overwhelming flood of data. Heart rate zones, VO2 max, HRV—what does it all mean, and does it even matter?

In this article, we'll simplify things. We’ll show you which metrics are worth paying attention to, what they tell you about your health, and how to use them to make better decisions.

What is a wearable?

A wearable is any device you wear on your body that collects and tracks health data. Think Apple Watch, Garmin, Fitbit, Oura Ring, and Whoop. These devices measure everything from how many steps you take to how well you sleep.

Wearables are not just a trend—they’re becoming essential tools for personal health. With global awareness around fitness and prevention growing, the wearable technology market is booming: by 2030, it’s projected to grow to $150 billion globally.

The problem with wearable data

Here’s the issue: most people don’t know what to do with the data their wearable devices produce. You might check your heart rate or step count out of habit, but without understanding the numbers, you can’t use them to improve your health.

Adding to the confusion, wearables track so many metrics that it’s easy to get lost. Sleep stages, calories, blood oxygen—where do you even begin?

The solution: focus on what matters

The key is to keep things simple. Instead of worrying about every piece of data your wearable throws at you, focus on a few key metrics that are both:

1. Important for understanding your health.
2. Accurately measured by most modern devices.

You can even adjust your wearable’s settings to display only the data you need. Less clutter means better focus and fewer distractions.

Six wearable metrics that matter

1. Resting heart rate

Your resting heart rate is the number of times your heart beats per minute when you’re at rest. A lower RHR generally indicates better cardiovascular fitness.

• Why it matters: Changes in your RHR can signal stress, fatigue, illness, or improvements in fitness.
• Healthy range: 60-100 bpm (but athletes often have lower rates).

2. Exercise heart rate

During exercise, your heart rate helps you understand how hard you’re working. Training zones are percentage ranges of your maximum heart rate (e.g., 70-85%).

• Why it matters: Staying in the right zone ensures you’re training effectively for your goals—fat loss, endurance, or speed.
• Tip: Most wearables automatically show zones during workouts. Enter your maximum heart rate (if you know it) to improve the precision of the zones.

3. Total sleep time

Forget complicated sleep stages. Total sleep time is a simple, reliable indicator of sleep quality.

• Why it matters: Getting 7-9 hours of sleep is essential for recovery, focus, and overall health.
• Tip: Look for trends over weeks, not just nightly variations.

4. Heart rate variability (HRV)

HRV measures the variation in time between heartbeats. It reflects how well your body is balancing stress and recovery.

• Why it matters: Higher HRV usually means you’re well-rested and ready to perform. Lower HRV can indicate stress, illness, or overtraining.
• Note: HRV is highly individual—track changes over time.

5. Steps

Step count is a straightforward way to track daily activity.

• Why it matters: Regular movement reduces the risk of chronic disease and improves mental health.
• Target: Aim for at least 7,000-10,000 steps per day.

6. VO2 max

VO2 max is a measure of how efficiently your body uses oxygen during exercise. It’s one of the best indicators of cardiovascular fitness and longevity.

• Why it matters: Improving your VO2 max means better endurance and overall health.
• How to improve it: Regular aerobic exercise and interval training.

A note on accuracy

Wearables have come a long way, but not all devices measure metrics equally well. Accuracy varies widely depending on the brand and type of device. For example:

• Heart rate and steps are generally accurate across most major brands.
• Sleep stages and calories are still prone to error. Metrics like these involve algorithms that can be influenced by movement or body composition, leading to inaccuracies.

To get the best data, stick with established brands like Apple, Garmin, Polar, and Fitbit. Investing a little more in a high-quality wearable is worth it if you’re serious about your health and wellbeing.

Final thoughts

Wearables are powerful allies in your health journey. By focusing on a few key metrics—like resting heart rate, total sleep time, and VO2 max—you can cut through the noise and make meaningful changes to your health.

Let your wearable be your ally in building a healthier future. Simplify, focus, and take acti