Wearable Wars: Who’s Tracking You & Is It Worth It?
Comparing the Apple Watch, Whoop, Oura and Ultrahuman Rings and Withings
I have tried all these, so you don’t have to.
Health wearables have exploded in popularity, promising better sleep, fitness, and recovery tracking. But with so many options—Apple Watch, Whoop, Withings, Oura, and Ultrahuman Rings—which one is actually worth your money?
More importantly, do these devices improve your health, or are they just expensive digital trophies?
In this breakdown, we’ll compare features, accuracy, HRV (Heart Rate Variability) and “strain” tracking, battery life, hidden costs, and privacy concerns—so you can make the best choice for your lifestyle.
We have come a long way since the pedometer - which I used to buy and give to my post op surgery patients to encourage them to walk.
What Do These Devices Track?
Most modern wearables track heart rate, sleep, HRV, activity levels, and even blood oxygen and temperature. More than just steps - which they all track, but each device has its strengths:
Apple Watch – Tracks HRV, ECG (FDA-cleared for atrial fibrillation), and fall detection. However, cellular models require a monthly subscription for full use, and it no longer tracks blood oxygen (SpO2) due to a patent dispute.
Whoop – Focuses on recovery, strain, and sleep—but requires a costly subscription and has no screen.
Oura Ring – A discreet ring tracking sleep stages, HRV, and body temperature.
I have been a fan of Withings Watches for years. They look like a great watch, and everyone seems to have an Apple watch. So I decided to buy a new one, because I missed the look of a great watch Withings – The only one besides Apple to be FDA-cleared for atrial fibrillation detection, with a focus on medical-grade tracking (smart scales, blood pressure monitors, and sleep mats). Unlike Apple, Withings still tracks blood oxygen (SpO2). Withings also tracks heart rate continuously during sleep, and thanks to its long battery life, it can be worn at night for weeks without interruption. No subscription required.
Ultrahuman Ring – A newer ring with a focus on metabolic tracking and recovery.
Scientific Insight:
A 2020 Nature Digital Medicine study found that wrist-based devices overestimate activity but underestimate calories burned, while rings tend to be more reliable for sleep and HRV.
HRV and Strain: What Do These Metrics Really Mean?
What is HRV (Heart Rate Variability)?
HRV is the variation in time between heartbeats—a measure of how well your autonomic nervous system is functioning.
Higher HRV = Better recovery, lower stress, and improved cardiovascular health.
Lower HRV = Fatigue, overtraining, stress, or even illness.
However, HRV is highly variable based on factors like hydration, sleep, and time of day.
How Wearables Measure HRV:
Apple Watch, Whoop, Oura, Withings, and Ultrahuman all track HRV, but accuracy depends on when and how it’s measured.
Whoop and Oura measure HRV during deep sleep, which is considered more stable than spot-checks.
Apple Watch and Withings measure HRV periodically throughout the day, which may be less reliable due to external factors.
💡 Bottom Line: HRV is useful for tracking trends over time, but daily fluctuations can be misleading.
What is “Strain” and Is It Useful?
Strain is Whoop’s proprietary score that estimates how hard your body works based on HRV, heart rate, and activity levels.
High Strain = More exertion, requiring longer recovery.
Low Strain = Your body is well-recovered.
🚨 The Problem?
Strain scores don’t account for individual fitness levels—what’s high strain for one person may be normal for another.
External factors like caffeine, stress, and dehydration can artificially raise strain scores.
💡 Bottom Line: While strain tracking can help athletes fine-tune training, it’s not always meaningful for the average user.
Accuracy & Reliability: Can You Trust the Data?
Not all wearables are created equal.
Withings and Apple Watch are both FDA-cleared for atrial fibrillation detection, meaning they have been tested for medical accuracy.
Apple Watch’s ECG is 97% accurate for detecting AFib (JAMA Cardiology, 2023).
Whoop and Oura’s HRV tracking is solid, but they are not medical-grade devices.
Withings devices have been used in clinical research, meaning their data is considered highly reliable for medical use.
Withings still provides blood oxygen (SpO2) tracking, while Apple Watch lost this feature due to a patent dispute.
Withings tracks heart rate continuously during sleep, while Apple Watch requires the user to trigger measurements manually or wear the device overnight (which can be inconvenient due to short battery life).
Bottom Line:
For medical-grade tracking, Withings and Apple Watch are the best choices.
For recovery & strain, Whoop and Oura perform well, but lack medical validation.
For long-term health monitoring, Withings is the clear winner.
More for our paid subscribers below - comparing battery life, hidden costs and the overall winner