During this stage, your heartbeat and breathing slow down further, eye movements stop, and body temperature drops. The brain continues to slow its activity, but sudden bursts of electrical signals, known as sleep spindles, still occur. These play an important role in memory and learning.
Stage Three: Deep Restorative Sleep
Stage three is essential for physical recovery. At this point, your heartbeat and breathing reach their lowest levels, muscles are fully relaxed, and it becomes very difficult to wake you. This is when the body repairs tissues and strengthens the immune system.
