What can wearables NOT tell me about my heart health?

Wearables cannot measure ApoB, Lp(a), hs-CRP, coronary artery calcium, carotid intima-media thickness, ejection fraction, valve function, bundle branch block, ST-segment depression, chamber hypertrophy, or practically any structural or biochemical cardiac finding that cardiologists use for risk stratification. A $399 Oura ring cannot tell you whether you have silent LAD disease. A Whoop band cannot tell you whether your ApoB is building plaque in your coronary arteries. A perfect wearable recovery score can coexist with a CAC score of 400.

The clinical consequence of this limitation is specific and important: do not let consistently positive wearable data substitute for a cardiac workup. The man who watches his HRV improve over six months, celebrates his resting heart rate of 48, and decides he does not need a CAC score or a lipid panel has made a category error. Wearables cover rhythm, rate, activity, and sleep architecture. They do not cover the primary drivers of the cardiovascular events most likely to kill men at 50: atherogenic particle count, inflammatory burden, and subclinical coronary plaque. Those require blood draws and imaging. (Apple Health website, https://www.apple.com/health/)

Cardiologist's calibrated position, Solid (1) for this list of limitations. This is a factual statement about sensor physics and biochemistry, not a criticism of wearable technology.

What to do: Use your wearable for what it actually measures. Book a CAC score and ApoB test for what it cannot. Both tools answer different questions. You need both.

For the full picture, read What Your Apple Watch Is Trying to Tell You.