What is improving sleep quality?

The mechanism by which exercise improves sleep quality and the reasons for it.

Types of sleep
Sleep is generally divided into the following four stages.

1. Non-REM sleep (NREM):
- Stage 1: Light sleep, a state where consciousness is hazy.
- Stage 2: Consciousness decreases further, and muscle tension relaxes. It accounts for about 50% of sleep.
- Stage 3: Deep sleep, the stage where the body and brain rest the most. It is characterized by slow brain waves called delta waves.

2. REM sleep (REM):
- A stage where you often dream. The brain is active, and memory organization and emotional processing take place.

Why deep sleep is good
The reasons why deep sleep (non-REM sleep stage 3) is important are as follows:
1. Physical recovery:
- Growth hormone is secreted during deep sleep, promoting cell repair and growth. Muscle and tissue repair and strengthening of immune function occur.
2. Brain rest:
- Because the brain rests the most during deep sleep, mental and cognitive performance for the next day improves. Waste products in the brain are also discharged at this time.
3. Memory consolidation:
- Information and experiences learned are organized at this stage and consolidated as long-term memory.
4. Emotional regulation:
- If deep sleep is insufficient, stress tolerance decreases, and emotional regulation can become difficult. Deep sleep also contributes to emotional stability.

Relationship between exercise and sleep quality
- Timing of exercise: Exercise done in the morning or during the day improves the quality of sleep at night. On the other hand, doing intense exercise right before bed can have the opposite effect.
- Type and intensity of exercise: Aerobic exercise (e.g., walking, jogging, cycling) and exercises with relaxing effects such as yoga promote deep sleep. Moderate-intensity exercise is effective.
- Formation of rhythm: Regular exercise regulates the body clock and forms a natural sleep rhythm. This makes falling asleep smoother and reduces nighttime awakenings.

Summary
Exercise promotes deep sleep and helps with physical and brain recovery, memory consolidation, and emotional regulation. Because this improves the next day's performance and mental health, exercise is an important factor in enhancing sleep quality.