Is it better to sleep on a hard mattress or a soft mattress?

Until a few years ago there was the fashion of sleeping on hard orthopedic mattresses. In recent years, however, we understand that a too rigid mattress can lead to circulation problems. So, a good quality mattress should be balanced, neither too hard nor too soft in the center. What matters in a modern mattress and quality is the characteristic of adjust to the shape of the body without compressing them. In this connection it was born the memory form.