A bit late, but I want to share my experience anyways. I have been sleeping for 4,5 hours every day for about a year now and so far so good. Just make sure you get about 4,5 hours maybe, I have been sleeping even less than that, but after a while you won't be able to keep on doing that. Another tip from me , follow your sleeping cycles. As you might know when taking a catnap, it shouldn't last longer than 30 minutes. This is because in the first 30 minutes we are not yet in our deepest sleep, which follows the next hour. So, you have cycles of 1,5 hours, than you get back to 'light' sleep. If you wake up then, you will feel more refreshed them waking up 30 minutes later. That is also why I sleep 4,5 hours, not 4.