Apple recently pushed out Watch OS 1.0.1 to the Apple Watch, which looks to have watered down the heart rate monitor on Watch compared to when it first launched with v1.0 software.
Before the v1.0.1 patch, Watch was recording the heart rate of Watch wearers every 10 minutes, but post-patch, it is no longer being recorded anywhere near as frequent. Apple has updated its website, where it has said: "Apple Watch attempts to measure your heart rate every ten minutes, but won't record it when you are in motion or your arm is moving". The original v1.0 software did not differentiate between a Watch user and their arm being still, or moving.
Watch owners thought that the original software was recording their heart rate details without problems, but post-patch, users are up in arms over the new heart rate monitor. Some are questioning whether Apple baked in the change to safe battery life on Watch, but at the cost of the heart rate monitor not being as accurate as the original OS when it launched not too long ago.