It seems that some schools combine long hours with revolving days off so that teachers find it hard to recharge their batteries, let alone keep up the quality of their teaching.
As so often this comes back to cultural norms. Many teachers come from a background in which it is normal for the working week to run from Monday to Friday leaving Saturday and Sunday free. It can thus be difficult to adjust to working, say, six days before a day off arrives. Also if the two-day weekend is not on offer, the teachers’ chunk of free time is diluted and they find they can’t, for example, take an extended trip.
The same cultural expectations underpin teaching hours. The western model is for maximum to be around 24 or 25 contact hours but those hours are well prepared and ensure a dynamic performance from teachers. In some situations elsewhere, teachers are asked to teach 30 or more hours and find it hard to keep up. But if long hours in the classroom are required, it is probably expected that the teaching is more passive, with students doing some quiet work in the classroom that perhaps normally they would do for homework.
As so many teachers going abroad to teach are fairly new to the profession, it is very important for employers to explain exactly how the timetable works and what sort of input is expected. For example, if a teacher has the same class for three hours in the morning with just a short break midway, then has another three-hour class in the afternoon, it is necessary to vary the pace quite considerably for the sake of both teacher and students. At least some of that time could justifiably be devoted to fairly mechanical consolidation activities while the teacher can focus on preparation.
Teachers need to think also how they can recycle their lessons. If the school does not give them adequate preparation time, then all the lessons they do prepare will have to be reusable.
Another time-related problem occurs when teachers have to work on split sites and so lose time in traveling from one place to another. I think in general that young, enthusiastic teachers are willing to work hard but schools must realize that the quality of classroom delivery will be reflected in the way they treat their staff. If teachers are overworked, and physically tired by traveling long distances between assignments, they will not be able to maintain the creative classroom presence that we associate with English language teaching.