If your watch says you burned 800 calories today, don’t trust it.

This is my usual morning run, I go for about an hour and try to stay in Zone II, which is 60-70% of my max heart rate.

Fat burning territory.

I only trust my average heart rate and total time running,

I never trust calorie burn. It’s only a wild guess.

A Stanford study tested seven popular fitness trackers, and none were accurate for calorie burn, with some off by as much as 93%.

The reason is that they use rough estimates of heart rate movement, not your actual metabolism.

Calorie burn is personal. Age, muscle mass, stress, sleep, and hormones all play a role.

While wearables are great at tracking habits, steps, or even heart rate trends, when it comes to calories burned, they are playing the guessing game.

So WATCH out. 🙂