Countless new gadgets advertise the ability to monitor your stress. Some log heart rate; others record electrical impulses. Granted, the only 100% bombproof method would be collecting saliva and blood samples to chart your stress hormones. Even so, wearables do a really good job. For one week, I wore a Spire monitor ($150, spire.io), which tracks respiratory rhythms. Here are three things I learned.
What our correspondent learned after spending a week under the watchful gaze of the newest body tracker.