Do Sleep Trackers Even Know That You’re Asleep?

Do Sleep trackers work?

Fitness Trackers are increasingly offering sleep tracking as one of their many features. Sleep tracking in of itself may seem like something small, but it actually helps improve your overall wellbeing.

Firstly, let’s talk sleep

We don’t know why we sleep. We know it’s good for us, but there is no research (at least to my knowledge) that gives definitive proof why it’s good for us. But, we do have an idea of what goes on when you sleep.

You go through a number of stages during your average sleep cycle. Sleep stages can be split into three main groups: Light Sleep, Deep Sleep, and Rapid Eye Movement (or REM). Light Sleep and Deep Sleep are fairly self-explanatory, so I won’t go into them in detail. During REM your brain is almost as active as when you are awake. And even though your eyes are closed, they move rapidly from side to side. This is the stage where we have our most vivid dreams.

The sleep cycle refers to how we move from one stage to another. Obviously, everyone has slightly different sleep cycles, but we move between the different stages multiple times during the night.

sleep tracker watch

How do they track sleep?

During sleep, your heart rate slows, and your body paralyses you to an extent to prevent you from acting out your dreams, meaning you are less active. Some stages are objectively better to wake up in. The reasoning behind sleep tracking is that if on a particular morning you wake up feeling great, you can understand during what stage you woke up.

But how well do they work?

While some fitness trackers claim that they can track what sleep stage you are currently in, some experts are sceptical. Long story short, sleep stages are defined by brain activity, not by physical activity. During different stages of sleep, your brain emits different electrical signals. These can be easily measured by specialised equipment, but in most cases, they need to be physically on your head.

Do you find that the more you sleep, the more tired you wake up? Tell us about your experiences in the comments below.