Zoom meetings and other forms of video conferencing have become the norm during the pandemic, but they can also be uncomfortably draining. Now, scientists say, they know why "zoom fatigue" happens and how to minimise it. There are four reasons why video calls sap our energy, according to study Nonverbal Overload: A Theoretical Argument for the Causes of Zoom Fatigue, carried out by Jeremy Bailenson, professor of communication at Stanford.