[zamadatix]

I don't think time worked linearly correlates with profitability, especially when talking about long timeframes. E.g. working 120 hours per week for a year is extremely unlikely to result in 3x the productivity as 40 hours a week. Same with working 3/5ths as much, it's unlikely to linearly scale down to 3/5ths the value (not that "it can't ever", just not as a typical expectation).

That aside, plenty of places offer a 4x10, or are fine with it when asked, and I think that's a more productive way to put in 40 hours each week while also being more convenient for yourself (before even getting into wanting to lower total hours).

[instagib]

4x10 is rough. I’ve been in positions that started with 5x8 then went to 4x10, then others 8,10, or 12 with built in overtime or comp time to get to 40hrs average.

You end up trying to cheat meals for speed eating unhealthy. High amounts of caffeine, little family time, and at least the first day off is usually wasted catching up on lost sleep. If you happen to do shift work, good luck trying to get much done as you need to shift to a different schedule to be somewhere during open hours.

We were more inefficient going from 5x8 to 4x10. Try training on little sleep before coffee kicks in. You need to re-do it later. Try sleeping after drinking coffee all day to stay awake, it’s great for your heart and blood pressure.

[zamadatix]

If you're already time constrained to the point working 2 extra hours means you can't get through the day without caffeine and skipping meals then of course it's a bad idea, but that's not an inherent fault of a 4x10 in itself.

A 4x10 is particularly attractive for those able to work remote and/or without lots of other time commitments. If you have an hour commute each way, kids to drop off/pick up from school/sports, responsibility for cooking meals 100% of the time, and so on then it really doesn't make sense to point the finger at the 2 extra hours as the sole root cause of the problem in that situation.