sleeping on the floor / on a futon . literally the easiest way to improve how your body feels and your looks at the same time because you don't have to think about it , sleeping on the floor will reduce back pain and spinal problems tremendously , whenever you sleep on a mattress your back and hips literally sink and get caved into your bed which causes weakness and misalignments , i used to have use back problems and sleeping on the floor legit fixed them in 3 months and better my overall body symetry , also it will better your posture a lot since it will keep your body straight and aligned during the night , there's more benefits like blood circulation and temperature regulation but you get the point , literally only upsides to doing it , don't know why it's not talked about more in these communities , personally i sleep on a futon which is the perfect in between to keep the comfort of the bed and the benefits of sleeping on the floor