Smartwatches infer sleep quality from wrist movement and HRV, but this data may not fully capture performance or underlying physiological states.

“if you dig too much into some of these different things that you lose track you start to lose track exactly of how do you increase performance of somebody as well because it to to use another example today we have for example SmartWatches and other things as well that are trying to say something about a sleep and it's it's derived or infered basically from movement from your from your wrist for example and it's based on HRV”