Why does the body feel weak after waking up?

Many of our cells are damaged as a result of working all day. As a result, when we sleep, our damaged cells recover. It burns a lot of calories in our body, which makes our body feel tired. Moreover, even when we sleep, our body has many functions going on, such as breathing, heartbeat, dreaming and many more. All this is controlled by our subconscious mind, which never sleeps. So when we wake up, our subconscious mind does so much work all night that it also takes a while to recover. Due to which we feel weak after waking up.