The One Thing Your Fitness Tracker Misses (But Your Heart Needs Daily)

We’ve entered an era where data drives everything — from sleep cycles to strain scores. Wearables like Oura Rings, Whoop bands, and Apple Watches can track nearly every heartbeat and breath. But even the most advanced devices miss one crucial indicator of heart health: your body’s Nitric Oxide (NO) levels.

Why Nitric Oxide Matters

Nitric Oxide is a simple gas with a powerful role — it signals blood vessels to relax and widen, improving blood flow and oxygen delivery throughout the body. It’s essential for healthy blood pressure, energy, recovery, sexual performance and overall cardiovascular function.

The challenge? Our ability to produce Nitric Oxide naturally declines with age — by 40, it decreases by 50% — as well as due to stress, poor diet, and even common habits like using antibacterial mouthwash. When NO levels fall, blood flow efficiency drops — long before you might see changes in heart rate or blood pressure readings.

What Wearables Can’t Measure

Fitness trackers excel at monitoring heart rate, heart rate variability (HRV), temperature, and recovery — but none measure how well blood is actually moving through your vessels.

Metrics like HRV or resting heart rate tell you how your body responds to stress or exertion, but they don’t capture the vascular side of performance — the ability of your arteries to dilate and deliver oxygen efficiently. That missing piece is what Nitric Oxide represents.

How to Check Your Nitric Oxide Levels at Home

Since wearables can't monitor Nitric Oxide, Berkeley Life's quick, at-home, non-invasive saliva-based test provides an easy way to gain insights into your vascular health.

Here’s how Berkeley Life's saliva-based NO test strips work:

1. Place the test strip on your tongue with the "saliva here" side facing down. Hold for 5 seconds.

2. Fold the strip in half, pressing the sides together gently for 10 seconds.

3. Unfold and compare your results with the Nitric Oxide Scale on the package — the darker the color, the higher your Nitric Oxide levels.

The test gives near-instant feedback on how your diet, hydration, or lifestyle may be influencing your circulation — something no wearable can currently do.

Connecting the Dots

If you already use a fitness tracker, consider pairing your daily data with Nitric Oxide testing.

• When recovery or HRV scores dip, check if your NO levels are also low.

• Track how nitrate-rich foods (like spinach, arugula, or beets) or lifestyle changes affect your readings over time.

This combination offers a fuller picture of cardiovascular readiness — both the electrical activity your wearable sees and the vascular function it can’t.

The Bottom Line

Smart rings and trackers can tell you how your heart is functioning. Nitric Oxide shows you how well your blood is flowing to support all those vital organs.

Berkeley Life simplifies the process of knowing your NO levels with a quick 15-second at-home test. For those who want to ensure optimal NO levels, consider Berkeley Life's two-capsule daily dose NO Foundation, which is clinically backed and made with a nitrate blend, vitamin C, and magnesium. Together, they offer a more comprehensive view of everyday, full-body health.