Yes, some teachers do this and have done this for a long time. Previously, they notified students in a little green box (for status updates) on their profile or included it in the course titles, specifying that it was a 55-minute lesson, not 60, or 25 as opposed 30. They do this because many teachers have to work several hours in a row, and that's not humanly possible without a short break to stretch, use the bathroom, maybe eat or drink something.

I don't do this, because I don't teach more than 2.5 hours in a row as a matter of preference. I don't like speaking longer than that and don't think I'm giving my best beyond that. However, I am glad that italki has written this officially, to show support for teachers who do need breaks and have to work more hours in a row.

If 5 minutes makes a big difference to you as a student, ask the teacher about their personal policy before you start taking regular lessons.

Thanks to everyone who has responded!

I have taken many lessons on Italki before, but I haven't seen this until today. It does not worry me as a student; I just wanted to hear a teacher's perspective.

Personally, I''m used to teaching three-hour lessons to classes of teenagers and adults, so no, I absolutely do not need a five-minute break during a one-hour lesson. If there are a few lessons back-to-back, I may excuse myself two minutes early to go the bathroom — students normally understand that, so I don't know why it would need to be an official policy. You can always ask potential teachers about that in your introductory message that you send before booking your first class.